Major rework/standardization:

* DDSEncoderType, DX10DXGIFormat merged with DDSType for a single way to describe a DDS format
 * Added constants for DXGI formats
 * DDSImageWriteParam is now mutable and supports standard way of setting compression type
 * DDSImageMetadata now supports more of the format
 Performance:
 * DDSReader now use seek() to jump to correct mipmap instead of reading all bytes
 * DDSImageWriter now uses getTile(0, 0) instead of getData() for better performance

imageio/imageio-core/src/main/java/com/twelvemonkeys/imageio/StandardImageMetadataSupport.java

@@ -23,6 +23,7 @@ import static com.twelvemonkeys.lang.Validate.notNull;
  * {@link ImageTypeSpecifier}.
  * Other values or overrides may be specified using the builder.
  *
+ * @see <a href="https://docs.oracle.com/en/java/javase/11/docs/api/java.desktop/javax/imageio/metadata/doc-files/standard_metadata.html">Standard (Plug-in Neutral) Metadata Format Specification</a>
  * @author <a href="mailto:harald.kuhr@gmail.com">Harald Kuhr</a>
  */
 public class StandardImageMetadataSupport extends AbstractMetadata {
@@ -79,11 +80,11 @@ public class StandardImageMetadataSupport extends AbstractMetadata {
         textEntries = builder.textEntries;
     }
 
-    public static Builder builder(ImageTypeSpecifier type) {
+    protected static Builder builder(ImageTypeSpecifier type) {
         return new Builder(type);
     }
 
-    public static class Builder {
+    protected static class Builder {
         private final ImageTypeSpecifier type;
         private ColorSpaceType colorSpaceType;
         private boolean blackIsZero = true;

imageio/imageio-core/src/main/java/com/twelvemonkeys/imageio/util/IIOUtil.java

@@ -35,6 +35,8 @@ import com.twelvemonkeys.lang.Validate;
 
 import javax.imageio.IIOParam;
 import javax.imageio.ImageIO;
+import javax.imageio.ImageReadParam;
+import javax.imageio.ImageWriteParam;
 import javax.imageio.spi.IIOServiceProvider;
 import javax.imageio.spi.ServiceRegistry;
 import javax.imageio.stream.ImageInputStream;
@@ -45,7 +47,9 @@ import java.io.BufferedInputStream;
 import java.io.BufferedOutputStream;
 import java.io.InputStream;
 import java.io.OutputStream;
+import java.util.Arrays;
 import java.util.Iterator;
+import java.util.Objects;
 import java.util.SortedSet;
 import java.util.TreeSet;
 
@@ -359,4 +363,109 @@ public final class IIOUtil {
             System.arraycopy(srcRow, srcPos + x, destRow, destPos + x / samplePeriod, pixelStride);
         }
     }
+
+    /**
+     * Copies all the standard param values from source to destination.
+     * <p>
+     * Typical use (in some imaginary {@code FooImageWriter} class):
+     * <pre>
+     * ImageWriteParam param = ...
+     * FooImageWriteparam fooParam = param instanceof FooImageWriteParam
+     *      ? (FooImageWriteParam) param
+     *      : copyStandardParams(param, getDefaultWriteParam());
+     * </pre>
+     * </p>
+     * May also be useful for {@code ImageReader}s that delegate reading to other plugins
+     * (like a TIFF plugin delegating JPEG format decoding to a {@code JPEGImageReader}).
+     *
+     * @param source the source parameter, may be {@code null}
+     * @param destination the destination parameter
+     * @return destination
+     *
+     * @param <T> the plugin specific subclass of {@code IIOParam}
+     *
+     * @throws NullPointerException if destination is {@code null}
+     */
+    public static <T extends IIOParam> T copyStandardParams(IIOParam source, T destination) {
+        Objects.requireNonNull(destination);
+        Validate.isTrue(source != destination, "source must be different from destination");
+
+        if (source != null) {
+            destination.setController(source.getController());
+            destination.setSourceSubsampling(
+                source.getSourceXSubsampling(), source.getSourceYSubsampling(),
+                source.getSubsamplingXOffset(), source.getSubsamplingYOffset()
+            );
+            destination.setSourceRegion(source.getSourceRegion());
+            destination.setSourceBands(source.getSourceBands());
+            destination.setDestinationOffset(source.getDestinationOffset());
+            destination.setDestinationType(source.getDestinationType());
+
+            // TODO: API & usage... Is it ever useful to copy from a read to a write param or vice versa?
+            //  If not, maybe throw an IllegalArgumentException instead
+
+            if (source instanceof ImageReadParam && destination instanceof ImageReadParam) {
+                ImageReadParam sourceReadParam = (ImageReadParam) source;
+                ImageReadParam destinationReadParam = (ImageReadParam) destination;
+
+                destinationReadParam.setDestination(sourceReadParam.getDestination());
+                destinationReadParam.setDestinationBands(sourceReadParam.getDestinationBands());
+
+                if (destinationReadParam.canSetSourceRenderSize()) {
+                    destinationReadParam.setSourceRenderSize(sourceReadParam.getSourceRenderSize());
+                }
+
+                destinationReadParam.setSourceProgressivePasses(
+                    sourceReadParam.getSourceMinProgressivePass(),
+                    sourceReadParam.getSourceMaxProgressivePass()
+                );
+            }
+
+            if (source instanceof ImageWriteParam && destination instanceof ImageWriteParam) {
+                ImageWriteParam sourceWriteParam = (ImageWriteParam) source;
+                ImageWriteParam destinationWriteParam = (ImageWriteParam) destination;
+
+                // TODO: Usage... It's very unlikely that compression settings of one plugin is compatible with another...
+                //  Is the the below useful?
+                //  Also, is it okay to just silently ignore settings from one format that isn't compatible with another?
+
+                // Quirky API, we can't query for compression mode, unless source.canWriteCompressed is true...
+                if (sourceWriteParam.canWriteCompressed() && destinationWriteParam.canWriteCompressed()) {
+                    int compressionMode = sourceWriteParam.getCompressionMode();
+                    destinationWriteParam.setCompressionMode(compressionMode);
+
+                    if (compressionMode == ImageWriteParam.MODE_EXPLICIT
+                        && sourceWriteParam.getCompressionType() != null) {
+                        if (Arrays.asList(destinationWriteParam.getCompressionTypes())
+                            .contains(sourceWriteParam.getCompressionType())) {
+                            destinationWriteParam.setCompressionType(sourceWriteParam.getCompressionType());
+                            destinationWriteParam.setCompressionQuality(sourceWriteParam.getCompressionQuality());
+                        }
+                    }
+                }
+
+                if (sourceWriteParam.canWriteProgressive() && destinationWriteParam.canWriteProgressive()) {
+                    destinationWriteParam.setProgressiveMode(sourceWriteParam.getProgressiveMode());
+                }
+                if (sourceWriteParam.canWriteTiles() && destinationWriteParam.canWriteTiles()) {
+                    int tilingMode = sourceWriteParam.getTilingMode();
+                    destinationWriteParam.setTilingMode(tilingMode);
+
+                    if (tilingMode == ImageWriteParam.MODE_EXPLICIT) {
+                        // TODO: What if source can offset (and has offsets) and dest can't? Is it ok to just ignore the setting?
+                        boolean canWriteOffsetTiles =
+                            sourceWriteParam.canOffsetTiles() && destinationWriteParam.canOffsetTiles();
+
+                        destinationWriteParam.setTiling(
+                            sourceWriteParam.getTileWidth(), sourceWriteParam.getTileHeight(),
+                            canWriteOffsetTiles ? sourceWriteParam.getTileGridXOffset() : 0,
+                            canWriteOffsetTiles ? sourceWriteParam.getTileGridYOffset() : 0
+                        );
+                    }
+                }
+            }
+        }
+
+        return destination;
+    }
 }

imageio/imageio-core/src/test/java/com/twelvemonkeys/imageio/util/IIOUtilTest.java

@@ -1,8 +1,20 @@
 package com.twelvemonkeys.imageio.util;
 
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.function.Executable;
+
 import static org.junit.jupiter.api.Assertions.*;
 
+import java.awt.Point;
+import java.awt.Rectangle;
+import java.awt.image.BufferedImage;
+
+import javax.imageio.ImageReadParam;
+import javax.imageio.ImageTypeSpecifier;
+import javax.imageio.ImageWriteParam;
+import javax.imageio.plugins.bmp.BMPImageWriteParam;
+import javax.imageio.plugins.jpeg.JPEGImageReadParam;
+
 /**
  * IIOUtilTest
  */
@@ -204,4 +216,220 @@ public class IIOUtilTest {
     private int divCeil(int numerator, int denominator) {
         return (numerator + denominator - 1) / denominator;
     }
+
+    @Test
+    void copyStandardParamsDestinationNull() {
+        assertThrows(NullPointerException.class, () -> IIOUtil.copyStandardParams(null, null));
+        assertThrows(NullPointerException.class, () -> IIOUtil.copyStandardParams(new ImageReadParam(), null));
+    }
+
+    @Test
+    void copyStandardParamsSame() {
+        ImageReadParam param = new ImageReadParam();
+        assertThrows(IllegalArgumentException.class, () -> IIOUtil.copyStandardParams(param, param));
+    }
+
+    @Test
+    void copyStandardParamsSourceNull() {
+        ImageReadParam param = new ImageReadParam() {
+            @Override
+            public void setSourceRegion(Rectangle sourceRegion) {
+                fail("Should not be invoked");
+            }
+        };
+
+        assertSame(param, IIOUtil.copyStandardParams(null, param));
+    }
+
+    @Test
+    void copyStandardParamsImageReadParam() {
+        int sourceXSubsampling = 3;
+        int sourceYSubsampling = 4;
+        int subsamplingXOffset = 1;
+        int subsamplingYOffset = 2;
+        Rectangle sourceRegion = new Rectangle(1, 2, 42, 43);
+        int[] sourceBands = { 0, 1, 2 };
+
+        Point destinationOffset = new Point(7, 9);
+        int[] destinationBands = { 2, 1, 0 };
+
+        ImageReadParam sourceParam = new ImageReadParam();
+        sourceParam.setSourceRegion(sourceRegion);
+        sourceParam.setSourceSubsampling(sourceXSubsampling, sourceYSubsampling, subsamplingXOffset, subsamplingYOffset);
+        sourceParam.setSourceBands(sourceBands);
+
+        sourceParam.setDestinationOffset(destinationOffset);
+        sourceParam.setDestinationBands(destinationBands);
+
+        JPEGImageReadParam jpegParam = IIOUtil.copyStandardParams(sourceParam, new JPEGImageReadParam());
+
+        assertEquals(sourceRegion, jpegParam.getSourceRegion());
+        assertEquals(sourceXSubsampling, jpegParam.getSourceXSubsampling());
+        assertEquals(sourceYSubsampling, jpegParam.getSourceYSubsampling());
+        assertEquals(subsamplingXOffset, jpegParam.getSubsamplingXOffset());
+        assertEquals(subsamplingYOffset, jpegParam.getSubsamplingYOffset());
+        assertArrayEquals(sourceBands, jpegParam.getSourceBands());
+
+        assertEquals(destinationOffset, jpegParam.getDestinationOffset());
+        assertArrayEquals(destinationBands, jpegParam.getDestinationBands());
+    }
+
+    @Test
+    void copyStandardParamsImageReadParamDestination() {
+        // Destination and destination type is mutually exclusive
+        BufferedImage destination = new BufferedImage(2, 2, BufferedImage.TYPE_INT_ARGB);
+
+        ImageReadParam sourceParam = new ImageReadParam();
+        sourceParam.setDestination(destination);
+
+        assertEquals(destination, IIOUtil.copyStandardParams(sourceParam, new JPEGImageReadParam()).getDestination());
+    }
+
+    @Test
+    void copyStandardParamsImageReadParamDestinationType() {
+        // Destination and destination type is mutually exclusive
+        ImageTypeSpecifier destinationType = ImageTypeSpecifier.createFromBufferedImageType(BufferedImage.TYPE_BYTE_GRAY);
+
+        ImageReadParam sourceParam = new ImageReadParam();
+        sourceParam.setDestinationType(destinationType);
+
+        assertEquals(destinationType, IIOUtil.copyStandardParams(sourceParam, new JPEGImageReadParam()).getDestinationType());
+    }
+
+    @Test
+    void copyStandardParamsReadToWrite() {
+        int sourceXSubsampling = 3;
+        int sourceYSubsampling = 4;
+        int subsamplingXOffset = 1;
+        int subsamplingYOffset = 2;
+        Rectangle sourceRegion = new Rectangle(1, 2, 42, 43);
+        int[] sourceBands = { 0, 1, 2 };
+
+        Point destinationOffset = new Point(7, 9);
+
+        ImageWriteParam sourceParam = new ImageWriteParam(null);
+        sourceParam.setSourceRegion(sourceRegion);
+        sourceParam.setSourceSubsampling(sourceXSubsampling, sourceYSubsampling, subsamplingXOffset, subsamplingYOffset);
+        sourceParam.setSourceBands(sourceBands);
+
+        sourceParam.setDestinationOffset(destinationOffset);
+
+        JPEGImageReadParam jpegParam = IIOUtil.copyStandardParams(sourceParam, new JPEGImageReadParam());
+
+        assertEquals(sourceRegion, jpegParam.getSourceRegion());
+        assertEquals(sourceXSubsampling, jpegParam.getSourceXSubsampling());
+        assertEquals(sourceYSubsampling, jpegParam.getSourceYSubsampling());
+        assertEquals(subsamplingXOffset, jpegParam.getSubsamplingXOffset());
+        assertEquals(subsamplingYOffset, jpegParam.getSubsamplingYOffset());
+        assertArrayEquals(sourceBands, jpegParam.getSourceBands());
+
+        assertEquals(destinationOffset, jpegParam.getDestinationOffset());
+        assertNull(jpegParam.getDestinationBands()); // Only in read param
+    }
+
+    @Test
+    void copyStandardParamsImageWriteParam() {
+        int sourceXSubsampling = 3;
+        int sourceYSubsampling = 4;
+        int subsamplingXOffset = 1;
+        int subsamplingYOffset = 2;
+        Rectangle sourceRegion = new Rectangle(1, 2, 42, 43);
+        int[] sourceBands = { 0, 1, 2 };
+
+        Point destinationOffset = new Point(7, 9);
+
+        ImageWriteParam sourceParam = new ImageWriteParam(null);
+        sourceParam.setSourceRegion(sourceRegion);
+        sourceParam.setSourceSubsampling(sourceXSubsampling, sourceYSubsampling, subsamplingXOffset, subsamplingYOffset);
+        sourceParam.setSourceBands(sourceBands);
+
+        sourceParam.setDestinationOffset(destinationOffset);
+
+        BMPImageWriteParam fooParam = IIOUtil.copyStandardParams(sourceParam, new BMPImageWriteParam());
+
+        assertEquals(sourceRegion, fooParam.getSourceRegion());
+        assertEquals(sourceXSubsampling, fooParam.getSourceXSubsampling());
+        assertEquals(sourceYSubsampling, fooParam.getSourceYSubsampling());
+        assertEquals(subsamplingXOffset, fooParam.getSubsamplingXOffset());
+        assertEquals(subsamplingYOffset, fooParam.getSubsamplingYOffset());
+        assertArrayEquals(sourceBands, fooParam.getSourceBands());
+
+        assertEquals(destinationOffset, fooParam.getDestinationOffset());
+    }
+
+    @Test
+    void copyStandardParamsImageWriteParamEverything() {
+        int sourceXSubsampling = 3;
+        int sourceYSubsampling = 4;
+        int subsamplingXOffset = 1;
+        int subsamplingYOffset = 2;
+        Rectangle sourceRegion = new Rectangle(1, 2, 42, 43);
+        int[] sourceBands = { 0, 1, 2 };
+
+        Point destinationOffset = new Point(7, 9);
+
+        String compressionType = "Foo";
+        float quality = 0.42f;
+
+        ImageWriteParam sourceParam = new ImageWriteParam() {
+            {
+                canWriteProgressive = true;
+
+                canWriteTiles = true;
+                canOffsetTiles = true;
+
+                canWriteCompressed = true;
+                compressionTypes = new String[] { "Foo", "Bar" };
+            }
+        };
+        sourceParam.setSourceRegion(sourceRegion);
+        sourceParam.setSourceSubsampling(sourceXSubsampling, sourceYSubsampling, subsamplingXOffset, subsamplingYOffset);
+        sourceParam.setSourceBands(sourceBands);
+
+        sourceParam.setDestinationOffset(destinationOffset);
+
+        sourceParam.setProgressiveMode(ImageWriteParam.MODE_DEFAULT); // Default is COPY_FROM_METADATA...
+        sourceParam.setTilingMode(ImageWriteParam.MODE_EXPLICIT);
+        sourceParam.setTiling(1, 2, 3, 4);
+        sourceParam.setCompressionMode(ImageWriteParam.MODE_EXPLICIT);
+        sourceParam.setCompressionType(compressionType);
+        sourceParam.setCompressionQuality(quality);
+
+        FooImageWriteParam fooParam = IIOUtil.copyStandardParams(sourceParam, new FooImageWriteParam());
+
+        assertEquals(sourceRegion, fooParam.getSourceRegion());
+        assertEquals(sourceXSubsampling, fooParam.getSourceXSubsampling());
+        assertEquals(sourceYSubsampling, fooParam.getSourceYSubsampling());
+        assertEquals(subsamplingXOffset, fooParam.getSubsamplingXOffset());
+        assertEquals(subsamplingYOffset, fooParam.getSubsamplingYOffset());
+        assertArrayEquals(sourceBands, fooParam.getSourceBands());
+
+        assertEquals(destinationOffset, fooParam.getDestinationOffset());
+
+        assertEquals(ImageWriteParam.MODE_DEFAULT, fooParam.getProgressiveMode());
+
+        assertEquals(ImageWriteParam.MODE_EXPLICIT, fooParam.getTilingMode());
+        assertEquals(1, fooParam.getTileWidth());
+        assertEquals(2, fooParam.getTileHeight());
+        assertEquals(3, fooParam.getTileGridXOffset());
+        assertEquals(4, fooParam.getTileGridYOffset());
+
+        assertEquals(ImageWriteParam.MODE_EXPLICIT, fooParam.getCompressionMode());
+        assertEquals(compressionType, fooParam.getCompressionType());
+        assertEquals(quality, fooParam.getCompressionQuality());
+    }
+
+    // A basic param that supports "everything"
+    static class FooImageWriteParam extends ImageWriteParam {
+        FooImageWriteParam() {
+            canWriteProgressive = true;
+
+            canWriteTiles = true;
+            canOffsetTiles = true;
+
+            canWriteCompressed = true;
+            compressionType = "Unset";
+            compressionTypes = new String[] { "Bar", "Foo" };
+        }
+    }
 }

imageio/imageio-dds/src/main/java/com/twelvemonkeys/imageio/plugins/dds/BlockCompression.java

@@ -0,0 +1,11 @@
+package com.twelvemonkeys.imageio.plugins.dds;
+
+enum BlockCompression {
+    BC1,
+    BC2,
+    BC3,
+    BC4,
+    BC5,
+//    BC6H,
+//    BC7
+}

imageio/imageio-dds/src/main/java/com/twelvemonkeys/imageio/plugins/dds/DDS.java

@@ -33,7 +33,7 @@ package com.twelvemonkeys.imageio.plugins.dds;
 
 @SuppressWarnings("unused")
 interface DDS {
-    int MAGIC = ('D' << 24) + ('D' << 16) + ('S' << 8) + ' '; //Big-Endian
+    int MAGIC = ('D' << 24) + ('D' << 16) + ('S' << 8) + ' '; // Big-Endian
     int HEADER_SIZE = 124;
 
     // Header Flags
@@ -56,16 +56,6 @@ interface DDS {
     //DX10 Resource Dimensions
     int D3D10_RESOURCE_DIMENSION_TEXTURE2D = 3;
 
-    //DXGI Formats (DX10)
-    int DXGI_FORMAT_BC1_UNORM = 71;
-    int DXGI_FORMAT_BC2_UNORM = 72;
-    int DXGI_FORMAT_BC3_UNORM = 77;
-    int DXGI_FORMAT_BC4_UNORM = 80;
-    int DXGI_FORMAT_BC5_UNORM = 83;
-    int DXGI_FORMAT_B8G8R8A8_UNORM_SRGB = 91;
-    int DXGI_FORMAT_B8G8R8X8_UNORM_SRGB = 93;
-    int DXGI_FORMAT_R8G8B8A8_UNORM_SRGB = 29;
-
     //dwCaps
     int DDSCAPS_COMPLEX = 0x8;
     int DDSCAPS_MIPMAP = 0x400000;

imageio/imageio-dds/src/main/java/com/twelvemonkeys/imageio/plugins/dds/DDSEncoderType.java

@@ -1,56 +0,0 @@
-package com.twelvemonkeys.imageio.plugins.dds;
-
-/**
- * Lists a number of supported encoders for block compressors and uncompressed types.
- * <a href="https://learn.microsoft.com/en-us/windows/win32/api/dxgiformat/ne-dxgiformat-dxgi_format">DXGI Format List</a>
- * <a href="https://learn.microsoft.com/en-us/windows/win32/direct3d10/d3d10-graphics-programming-guide-resources-block-compression#compression-algorithms">Compression Algorithms</a>
- * <a href="https://github.com/microsoft/DirectXTK12/wiki/DDSTextureLoader#remarks">An extended Non-DX10 FourCC list</a>
- */
-enum DDSEncoderType {
-    BC1(DDSType.DXT1.value(), DDS.DXGI_FORMAT_BC1_UNORM, 8),
-    BC2(DDSType.DXT2.value(), DDS.DXGI_FORMAT_BC2_UNORM, 16),
-    BC3(DDSType.DXT5.value(), DDS.DXGI_FORMAT_BC3_UNORM, 16),
-    BC4(0x31495441, DDS.DXGI_FORMAT_BC4_UNORM, 8),
-    BC5(0x32495441, DDS.DXGI_FORMAT_BC5_UNORM, 16);
-
-    private final int fourCC;
-    private final int dx10DxgiFormat;
-    private final int bitCountOrBlockSize;
-    private final int[] rgbaMask;
-
-    //fourCC constructor
-    DDSEncoderType(int fourCC, int dx10DxgiFormat, int blockSize) {
-        this.fourCC = fourCC;
-        this.dx10DxgiFormat = dx10DxgiFormat;
-        bitCountOrBlockSize = blockSize;
-        rgbaMask = null;
-    }
-
-    boolean isFourCC() {
-        return fourCC != 0;
-    }
-
-    int getFourCC() {
-        return fourCC;
-    }
-
-    boolean isAlphaMaskSupported() {
-        return !isFourCC() && rgbaMask[3] > 0;
-    }
-
-    boolean isBlockCompression() {
-        return this.isFourCC();
-    }
-
-    int getBitsOrBlockSize() {
-        return bitCountOrBlockSize;
-    }
-
-    public int[] getRGBAMask() {
-        return rgbaMask;
-    }
-
-    public int getDx10Format() {
-        return dx10DxgiFormat;
-    }
-}

imageio/imageio-dds/src/main/java/com/twelvemonkeys/imageio/plugins/dds/DDSHeader.java

@@ -30,11 +30,23 @@
 
 package com.twelvemonkeys.imageio.plugins.dds;
 
+import static com.twelvemonkeys.imageio.plugins.dds.DDSReader.A1R5G5B5_MASKS;
+import static com.twelvemonkeys.imageio.plugins.dds.DDSReader.A4R4G4B4_MASKS;
+import static com.twelvemonkeys.imageio.plugins.dds.DDSReader.A8B8G8R8_MASKS;
+import static com.twelvemonkeys.imageio.plugins.dds.DDSReader.A8R8G8B8_MASKS;
+import static com.twelvemonkeys.imageio.plugins.dds.DDSReader.R5G6B5_MASKS;
+import static com.twelvemonkeys.imageio.plugins.dds.DDSReader.R8G8B8_MASKS;
+import static com.twelvemonkeys.imageio.plugins.dds.DDSReader.X1R5G5B5_MASKS;
+import static com.twelvemonkeys.imageio.plugins.dds.DDSReader.X4R4G4B4_MASKS;
+import static com.twelvemonkeys.imageio.plugins.dds.DDSReader.X8B8G8R8_MASKS;
+import static com.twelvemonkeys.imageio.plugins.dds.DDSReader.X8R8G8B8_MASKS;
+
 import javax.imageio.IIOException;
 import javax.imageio.stream.ImageInputStream;
 import java.awt.Dimension;
 import java.io.IOException;
 import java.nio.ByteOrder;
+import java.util.Arrays;
 
 final class DDSHeader {
 
@@ -52,6 +64,8 @@ final class DDSHeader {
     private int blueMask;
     private int alphaMask;
 
+    DXT10Header dxt10Header;
+
     @SuppressWarnings("unused")
     static DDSHeader read(final ImageInputStream imageInput) throws IOException {
         DDSHeader header = new DDSHeader();
@@ -113,6 +127,10 @@ final class DDSHeader {
 
         int dwReserved2 = imageInput.readInt(); // [124,127]
 
+        if (header.fourCC == DDSType.DXT10.fourCC()) {
+            header.dxt10Header = DXT10Header.read(imageInput);
+        }
+
         return header;
     }
 
@@ -146,31 +164,95 @@ final class DDSHeader {
         return mipMapCount;
     }
 
-    int getBitCount() {
+    DDSType getType() throws IIOException {
-        return bitCount;
+        if (dxt10Header != null) {
+            return dxt10Header.getType();
+        }
+
+        return getRawType();
     }
 
-    int getFourCC() {
+    DDSType getRawType() throws IIOException {
-        return fourCC;
+        if ((pixelFormatFlags & DDS.PIXEL_FORMAT_FLAG_FOURCC) != 0) {
+            // DXT
+            return DDSType.fromFourCC(fourCC);
+        }
+        else if ((pixelFormatFlags & DDS.PIXEL_FORMAT_FLAG_RGB) != 0) {
+            // RGB
+            int alphaMask = ((pixelFormatFlags & 0x01) != 0) ? this.alphaMask : 0; // 0x01 alpha
+
+            if (bitCount == 16) {
+                if (redMask == A1R5G5B5_MASKS[0] && greenMask == A1R5G5B5_MASKS[1] && blueMask == A1R5G5B5_MASKS[2] && alphaMask == A1R5G5B5_MASKS[3]) {
+                    // A1R5G5B5
+                    return DDSType.A1R5G5B5;
+                }
+                else if (redMask == X1R5G5B5_MASKS[0] && greenMask == X1R5G5B5_MASKS[1] && blueMask == X1R5G5B5_MASKS[2] && alphaMask == X1R5G5B5_MASKS[3]) {
+                    // X1R5G5B5
+                    return DDSType.X1R5G5B5;
+                }
+                else if (redMask == A4R4G4B4_MASKS[0] && greenMask == A4R4G4B4_MASKS[1] && blueMask == A4R4G4B4_MASKS[2] && alphaMask == A4R4G4B4_MASKS[3]) {
+                    // A4R4G4B4
+                    return DDSType.A4R4G4B4;
+                }
+                else if (redMask == X4R4G4B4_MASKS[0] && greenMask == X4R4G4B4_MASKS[1] && blueMask == X4R4G4B4_MASKS[2] && alphaMask == X4R4G4B4_MASKS[3]) {
+                    // X4R4G4B4
+                    return DDSType.X4R4G4B4;
+                }
+                else if (redMask == R5G6B5_MASKS[0] && greenMask == R5G6B5_MASKS[1] && blueMask == R5G6B5_MASKS[2] && alphaMask == R5G6B5_MASKS[3]) {
+                    // R5G6B5
+                    return DDSType.R5G6B5;
+                }
+
+                throw new IIOException("Unsupported 16bit RGB image.");
+            }
+            else if (bitCount == 24) {
+                if (redMask == R8G8B8_MASKS[0] && greenMask == R8G8B8_MASKS[1] && blueMask == R8G8B8_MASKS[2] && alphaMask == R8G8B8_MASKS[3]) {
+                    // R8G8B8
+                    return DDSType.R8G8B8;
+                }
+
+                throw new IIOException("Unsupported 24bit RGB image.");
+            }
+            else if (bitCount == 32) {
+                if (redMask == A8B8G8R8_MASKS[0] && greenMask == A8B8G8R8_MASKS[1] && blueMask == A8B8G8R8_MASKS[2] && alphaMask == A8B8G8R8_MASKS[3]) {
+                    // A8B8G8R8
+                    return DDSType.A8B8G8R8;
+                }
+                else if (redMask == X8B8G8R8_MASKS[0] && greenMask == X8B8G8R8_MASKS[1] && blueMask == X8B8G8R8_MASKS[2] && alphaMask == X8B8G8R8_MASKS[3]) {
+                    // X8B8G8R8
+                    return DDSType.X8B8G8R8;
+                }
+                else if (redMask == A8R8G8B8_MASKS[0] && greenMask == A8R8G8B8_MASKS[1] && blueMask == A8R8G8B8_MASKS[2] && alphaMask == A8R8G8B8_MASKS[3]) {
+                    // A8R8G8B8
+                    return DDSType.A8R8G8B8;
+                }
+                else if (redMask == X8R8G8B8_MASKS[0] && greenMask == X8R8G8B8_MASKS[1] && blueMask == X8R8G8B8_MASKS[2] && alphaMask == X8R8G8B8_MASKS[3]) {
+                    // X8R8G8B8
+                    return DDSType.X8R8G8B8;
+                }
+
+                throw new IIOException("Unsupported 32bit RGB image.");
+            }
+
+            throw new IIOException("Unsupported bit count: " + bitCount);
+        }
+
+        throw new IIOException("Unsupported YUV or LUMINANCE image.");
     }
 
-    int getPixelFormatFlags() {
+    @Override
-        return pixelFormatFlags;
+    public String toString() {
-    }
+        return "DDSHeader{" +
-
+            "flags=" + flags +
-    int getRedMask() {
+            ", mipMapCount=" + mipMapCount +
-        return redMask;
+            ", dimensions=" + Arrays.toString(dimensions) +
-    }
+            ", pixelFormatFlags=" + pixelFormatFlags +
-
+            ", fourCC=" + fourCC +
-    int getGreenMask() {
+            ", bitCount=" + bitCount +
-        return greenMask;
+            ", redMask=" + redMask +
-    }
+            ", greenMask=" + greenMask +
-
+            ", blueMask=" + blueMask +
-    int getBlueMask() {
+            ", alphaMask=" + alphaMask +
-        return blueMask;
+            '}';
-    }
-
-    int getAlphaMask() {
-        return alphaMask;
     }
 }

imageio/imageio-dds/src/main/java/com/twelvemonkeys/imageio/plugins/dds/DDSImageDataEncoder.java

@@ -31,8 +31,10 @@ class DDSImageDataEncoder {
     private static final int BC4_CHANNEL_ALPHA = 3; //BC3 reuses algorithm from BC4 but uses alpha channelIndex for sampling.
     private static final int BC4_CHANNEL_GREEN = 1; //same re-usage as BC3 but for green channel BC5 uses
 
-    static void writeImageData(ImageOutputStream imageOutput, RenderedImage renderedImage, DDSEncoderType type) throws IOException {
+    static void writeImageData(ImageOutputStream imageOutput, RenderedImage renderedImage, BlockCompression compression) throws IOException {
-        switch (type) {
+        // TODO: compression == null for custom RGB data?
+
+        switch (compression) {
             case BC1:
                 new BlockCompressor1(false).encode(imageOutput, renderedImage);
                 break;
@@ -49,7 +51,7 @@ class DDSImageDataEncoder {
                 new BlockCompressor5().encode(imageOutput, renderedImage);
                 break;
             default:
-                throw new IllegalArgumentException("DDS Type is not supported for encoder yet : " + type);
+                throw new IllegalArgumentException("DDS block compression is not supported yet: " + compression);
         }
     }
 
@@ -423,7 +425,12 @@ class DDSImageDataEncoder {
         void encode(ImageOutputStream imageOutput, RenderedImage image) throws IOException {
             int blocksXCount = (image.getWidth() + 3) / 4;
             int blocksYCount = (image.getHeight() + 3) / 4;
-            Raster raster = image.getData();
+
+            if (image.getNumXTiles() != 1 || image.getNumYTiles() != 1) {
+                throw new IllegalArgumentException("Only single tile images supported");
+            }
+            Raster raster = image.getTile(0, 0);
+
             for (int blockY = 0; blockY < blocksYCount; blockY++) {
                 for (int blockX = 0; blockX < blocksXCount; blockX++) {
                     raster.getPixels(blockX * 4, blockY * 4, 4, 4, samples);

imageio/imageio-dds/src/main/java/com/twelvemonkeys/imageio/plugins/dds/DDSImageMetadata.java

@@ -35,24 +35,46 @@ import com.twelvemonkeys.imageio.StandardImageMetadataSupport;
 import javax.imageio.ImageTypeSpecifier;
 
 final class DDSImageMetadata extends StandardImageMetadataSupport {
-    DDSImageMetadata(ImageTypeSpecifier type, DDSHeader header) {
+
-        super(builder(type)
+    DDSImageMetadata(ImageTypeSpecifier specifier, DDSType type) {
-                      .withCompressionTypeName(compressionName(header))
+        super(builder(specifier)
-                      .withFormatVersion("1.0")
+            .withCompressionTypeName(compressionName(type))
+            .withBitsPerSample(bitsPerSample(type))
+            .withFormatVersion("1.0")
         );
     }
 
-    private static String compressionName(DDSHeader header) {
+    private static String compressionName(DDSType type) {
-        // If the fourCC is valid, compression is one of the DXTn versions, otherwise None
+        if (type != null && type.isFourCC()) {
-        int flags = header.getPixelFormatFlags();
-
-        if ((flags & DDS.PIXEL_FORMAT_FLAG_FOURCC) != 0) {
-            // DXTn
-            DDSType type = DDSType.valueOf(header.getFourCC());
-
             return type.name();
         }
 
         return "None";
     }
+
+    private static int[] bitsPerSample(DDSType type) {
+        if (type.isBlockCompression()) {
+            return null; // Use defaults
+        }
+
+        int[] bitsPerSample = new int[4];
+
+        for (int i = 0; i < bitsPerSample.length; i++) {
+            bitsPerSample[i] = countMaskBits(type.rgbaMasks[i]);
+        }
+
+        return bitsPerSample;
+    }
+
+    private static int countMaskBits(int mask) {
+        // See https://graphics.stanford.edu/~seander/bithacks.html#CountBitsSetKernighan
+        int count;
+
+        for (count = 0; mask != 0; count++) {
+            mask &= mask - 1; // clear the least significant bit set
+        }
+
+        return count;
+    }
+
 }

imageio/imageio-dds/src/main/java/com/twelvemonkeys/imageio/plugins/dds/DDSImageReader.java

@@ -48,6 +48,12 @@ import java.util.Iterator;
 
 import static com.twelvemonkeys.imageio.util.IIOUtil.subsampleRow;
 
+/**
+ * ImageReader implementation for Microsoft DirectDraw Surface (DDS) format.
+ *
+ * @author Paul Allen
+ * @author <a href="mailto:harald.kuhr@gmail.com">Harald Kuhr</a>
+ */
 public final class DDSImageReader extends ImageReaderBase {
 
     private DDSHeader header;
@@ -90,7 +96,11 @@ public final class DDSImageReader extends ImageReaderBase {
         checkBounds(imageIndex);
         readHeader();
 
-        // TODO: Implement for the specific formats...
+        DDSType type = header.getType();
+        if (!type.isBlockCompression() && type.rgbaMasks[3] == 0) {
+            return ImageTypeSpecifiers.createFromBufferedImageType(BufferedImage.TYPE_INT_RGB);
+        }
+
         return ImageTypeSpecifiers.createFromBufferedImageType(BufferedImage.TYPE_INT_ARGB);
     }
 
@@ -146,14 +156,13 @@ public final class DDSImageReader extends ImageReaderBase {
     public IIOMetadata getImageMetadata(int imageIndex) throws IOException {
         ImageTypeSpecifier imageType = getRawImageType(imageIndex);
 
-        return new DDSImageMetadata(imageType, header);
+        return new DDSImageMetadata(imageType, header.getType());
     }
 
     private void readHeader() throws IOException {
         if (header == null) {
             imageInput.setByteOrder(ByteOrder.LITTLE_ENDIAN);
             header = DDSHeader.read(imageInput);
-
             imageInput.flushBefore(imageInput.getStreamPosition());
         }
 

imageio/imageio-dds/src/main/java/com/twelvemonkeys/imageio/plugins/dds/DDSImageReaderSpi.java

@@ -55,7 +55,8 @@ public final class DDSImageReaderSpi extends ImageReaderSpiBase {
 
         try {
             return stream.readInt() == DDS.MAGIC;
-        } finally {
+        }
+        finally {
             stream.reset();
         }
     }
@@ -67,6 +68,6 @@ public final class DDSImageReaderSpi extends ImageReaderSpiBase {
 
     @Override
     public String getDescription(Locale locale) {
-        return "Direct DrawSurface (DDS) Image Reader";
+        return "DirectDraw Surface (DDS) Image Reader";
     }
 }

imageio/imageio-dds/src/main/java/com/twelvemonkeys/imageio/plugins/dds/DDSImageWriteParam.java

@@ -0,0 +1,99 @@
+package com.twelvemonkeys.imageio.plugins.dds;
+
+import javax.imageio.ImageWriteParam;
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.stream.Collectors;
+
+public final class DDSImageWriteParam extends ImageWriteParam {
+
+    static final DDSType DEFAULT_TYPE = DDSType.DXT5;
+    private static final String[] COMPRESSION_TYPES = compressionTypes();
+
+    private static String[] compressionTypes() {
+        // TODO: Maybe hardcode subset of values that we actually support writing?
+        List<String> compressionTypes = Arrays.stream(DDSType.values())
+            .filter(DDSType::isBlockCompression)
+            .map(Enum::name)
+            .collect(Collectors.toList());
+        compressionTypes.add(0, "None");
+
+        return compressionTypes.toArray(new String[0]);
+    }
+
+    private int optionalBitFlags;
+    private boolean writeDXT10;
+
+    DDSImageWriteParam() {
+        canWriteCompressed = true;
+        compressionTypes = COMPRESSION_TYPES;
+        compressionType = DEFAULT_TYPE.name();
+        setLinearSize();
+    }
+
+    // TODO: Set this always for compressed images?
+    public void setLinearSize() {
+        optionalBitFlags |= DDS.FLAG_LINEARSIZE;
+    }
+
+    public void clearLinearSize() {
+        optionalBitFlags &= ~DDS.FLAG_LINEARSIZE;
+    }
+
+    // TODO: Set this always for uncompressed images?
+    public void setPitch() {
+        optionalBitFlags |= DDS.FLAG_PITCH;
+    }
+
+    public void clearPitch() {
+        optionalBitFlags &= ~DDS.FLAG_PITCH;
+    }
+
+    // TODO: Other flags?
+
+    public int optionalBitFlags() {
+        return optionalBitFlags;
+    }
+
+    public void setWriteDX10() {
+        writeDXT10 = true;
+    }
+
+    public void clearWriteDX10() {
+        writeDXT10 = false;
+    }
+
+    public boolean isWriteDXT10() {
+        return writeDXT10;
+    }
+
+    BlockCompression compression() {
+        DDSType type = type();
+
+        if (type != null) {
+            return type.compression;
+        }
+
+        return null;
+    }
+
+    DDSType type() {
+        if (compressionType == null || compressionType.equals("None")) {
+            return null;
+        }
+
+        return DDSType.valueOf(compressionType);
+    }
+
+    int getDxgiFormat() {
+        DDSType type = type();
+
+        if (type != null) {
+            return type.dxgiFormat();
+        }
+
+        return DXGI.DXGI_FORMAT_UNKNOWN;
+
+    }
+}

imageio/imageio-dds/src/main/java/com/twelvemonkeys/imageio/plugins/dds/DDSImageWriter.java

@@ -1,6 +1,7 @@
 package com.twelvemonkeys.imageio.plugins.dds;
 
 import com.twelvemonkeys.imageio.ImageWriterBase;
+import com.twelvemonkeys.imageio.util.IIOUtil;
 
 import javax.imageio.IIOImage;
 import javax.imageio.ImageIO;
@@ -9,6 +10,7 @@ import javax.imageio.ImageWriteParam;
 import javax.imageio.metadata.IIOMetadata;
 import javax.imageio.spi.ImageWriterSpi;
 import javax.imageio.stream.MemoryCacheImageOutputStream;
+
 import java.awt.image.Raster;
 import java.awt.image.RenderedImage;
 import java.io.File;
@@ -18,8 +20,10 @@ import java.nio.file.Files;
 import java.nio.file.Paths;
 
 /**
- * A designated class to begin writing DDS file with headers,
+ * ImageWriter implementation for Microsoft DirectDraw Surface (DDS) format.
- * {@link DDSImageDataEncoder} will handle image data encoding process
+ *
+ * @author KhanTypo
+ * @author <a href="mailto:harald.kuhr@gmail.com">Harald Kuhr</a>
  */
 class DDSImageWriter extends ImageWriterBase {
     protected DDSImageWriter(ImageWriterSpi provider) {
@@ -27,31 +31,34 @@ class DDSImageWriter extends ImageWriterBase {
     }
 
     @Override
-    public DDSImageWriterParam getDefaultWriteParam() {
+    public DDSImageWriteParam getDefaultWriteParam() {
-        return DDSImageWriterParam.builder().formatBC5().build();
+        return new DDSImageWriteParam();
     }
 
     @Override
     public void write(IIOMetadata streamMetadata, IIOImage image, ImageWriteParam param) throws IOException {
         assertOutput();
-        RenderedImage renderedImage = image.getRenderedImage();
+
+        RenderedImage renderedImage = image.getRenderedImage(); // TODO: Support raster?
         ensureTextureSize(renderedImage);
         ensureImageChannels(renderedImage);
 
-        // TODO: Need to copy params from 'param' here in case of non-DDS param...
+        DDSImageWriteParam ddsParam = param instanceof DDSImageWriteParam
-        DDSImageWriterParam ddsParam = param instanceof DDSImageWriterParam ? ((DDSImageWriterParam) param) : getDefaultWriteParam();
+            ? ((DDSImageWriteParam) param)
+            : IIOUtil.copyStandardParams(param, getDefaultWriteParam());
 
         processImageStarted(0);
         imageOutput.setByteOrder(ByteOrder.BIG_ENDIAN);
         imageOutput.writeInt(DDS.MAGIC);
         imageOutput.setByteOrder(ByteOrder.LITTLE_ENDIAN);
 
-        writeHeader(image, ddsParam);
+        writeHeader(image, ddsParam.type(), ddsParam.isWriteDXT10(), ddsParam.optionalBitFlags());
-        writeDXT10Header(ddsParam);
+        if (ddsParam.isWriteDXT10()) {
+            writeDXT10Header(ddsParam.getDxgiFormat());
+        }
 
-        //image data encoding
         processImageProgress(0f);
-        DDSImageDataEncoder.writeImageData(imageOutput, renderedImage, ddsParam.getEncoderType());
+        DDSImageDataEncoder.writeImageData(imageOutput, renderedImage, ddsParam.compression());
         processImageProgress(100f);
 
         imageOutput.flush();
@@ -62,13 +69,18 @@ class DDSImageWriter extends ImageWriterBase {
      * Checking if the image has 3 channels (RGB) or 4 channels (RGBA) and if image has 8 bits/channel.
      */
     private void ensureImageChannels(RenderedImage renderedImage) {
-        Raster data = renderedImage.getData();
+        Raster data = renderedImage.getTile(0, 0);
+
         int numBands = data.getNumBands();
-        if (numBands < 3)
+        if (numBands < 3) {
-            throw new IllegalStateException("Only image with 3 channels (RGB) or 4 channels (RGBA) is supported, got " + numBands + " channels");
+            throw new IllegalStateException(
+                "Only image with 3 channels (RGB) or 4 channels (RGBA) is supported, got " + numBands + " channels");
+        }
+
         int sampleSize = data.getSampleModel().getSampleSize(0);
-        if (sampleSize != 8)
+        if (sampleSize != 8) {
             throw new IllegalStateException("Only image with 8 bits/channel is supported, got " + sampleSize);
+        }
     }
 
     /**
@@ -78,20 +90,23 @@ class DDSImageWriter extends ImageWriterBase {
     private void ensureTextureSize(RenderedImage renderedImage) {
         int w = renderedImage.getWidth();
         int h = renderedImage.getHeight();
-        if (w % 4 != 0 || h % 4 != 0)
+
+        if (w % 4 != 0 || h % 4 != 0) {
             throw new IllegalStateException(String.format("Image size must be dividable by 4, ideally a power of 2; got (%d x %d)", w, h));
+        }
     }
 
-
+    private void writeHeader(IIOImage image, DDSType type, boolean writeDXT10, int optionalBitFlags) throws IOException {
-    private void writeHeader(IIOImage image, DDSImageWriterParam param) throws IOException {
         imageOutput.writeInt(DDS.HEADER_SIZE);
-        imageOutput.writeInt(DDS.FLAG_CAPS | DDS.FLAG_HEIGHT | DDS.FLAG_WIDTH | DDS.FLAG_PIXELFORMAT | param.getOptionalBitFlags());
+        imageOutput.writeInt(DDS.FLAG_CAPS | DDS.FLAG_HEIGHT | DDS.FLAG_WIDTH | DDS.FLAG_PIXELFORMAT | optionalBitFlags);
+
         RenderedImage renderedImage = image.getRenderedImage();
         int height = renderedImage.getHeight();
-        imageOutput.writeInt(height);
         int width = renderedImage.getWidth();
+
+        imageOutput.writeInt(height);
         imageOutput.writeInt(width);
-        writePitchOrLinearSize(height, width, param);
+        writePitchOrLinearSize(height, width, type);
         //dwDepth
         imageOutput.writeInt(0);
         //dwMipmapCount
@@ -99,7 +114,7 @@ class DDSImageWriter extends ImageWriterBase {
         //reserved
         imageOutput.write(new byte[44]);
         //pixFmt
-        writePixelFormat(param);
+        writePixelFormat(type, writeDXT10);
         //dwCaps, right now we keep it simple by only using DDSCAP_TEXTURE as it is required.
         imageOutput.writeInt(DDS.DDSCAPS_TEXTURE);
         //dwCaps2, unused for now as we are not working with cube maps
@@ -110,86 +125,95 @@ class DDSImageWriter extends ImageWriterBase {
     }
 
     //https://learn.microsoft.com/en-us/windows/win32/direct3ddds/dds-pixelformat
-    private void writePixelFormat(DDSImageWriterParam param) throws IOException {
+    private void writePixelFormat(DDSType type, boolean writeDXT10) throws IOException {
         imageOutput.writeInt(DDS.DDSPF_SIZE);
-        writePixelFormatFlags(param);
+        writePixelFormatFlags(type, writeDXT10);
-        writeFourCC(param);
+        writeFourCC(type, writeDXT10);
-        writeRGBAData(param);
+        writeRGBAData(type, writeDXT10);
     }
 
-    private void writeDXT10Header(DDSImageWriterParam param) throws IOException {
+    private void writeDXT10Header(int dxgiFormat) throws IOException {
-        if (param.isUsingDxt10()) {
+        //dxgiFormat
-            //dxgiFormat
+        imageOutput.writeInt(dxgiFormat);
-            imageOutput.writeInt(param.getDxgiFormat());
+        //resourceDimension
-            //resourceDimension
+        imageOutput.writeInt(DDS.D3D10_RESOURCE_DIMENSION_TEXTURE2D);
-            imageOutput.writeInt(DDS.D3D10_RESOURCE_DIMENSION_TEXTURE2D);
+        //miscFlag
-            //miscFlag
+        imageOutput.writeInt(0);
-            imageOutput.writeInt(0);
+        //arraySize
-            //arraySize
+        imageOutput.writeInt(1);
-            imageOutput.writeInt(1);
+        //miscFlag2
-            //miscFlag2
+        imageOutput.writeInt(0);
-            imageOutput.writeInt(0);
-        }
     }
 
-    private void writeRGBAData(DDSImageWriterParam param) throws IOException {
+    private void writeRGBAData(DDSType type, boolean writeDXT10) throws IOException {
-        if (!param.isUsingDxt10() && !param.getEncoderType().isFourCC()) {
+        if (!writeDXT10 && !type.isFourCC()) {
             //dwRGBBitCount
-            imageOutput.writeInt(param.getEncoderType().getBitsOrBlockSize());
+            imageOutput.writeInt(type.blockSize() * 8); // TODO: Is bitcount always a multiple of 8?
 
-            int[] mask = param.getEncoderType().getRGBAMask();
+            int[] mask = type.rgbaMasks;
             //dwRBitMask
             imageOutput.writeInt(mask[0]);
             //dwGBitMask
             imageOutput.writeInt(mask[1]);
-            //dwBitMask
+            //dwBBitMask
             imageOutput.writeInt(mask[2]);
             //dwABitMask
             imageOutput.writeInt(mask[3]);
-        } else {
+        }
+        else {
             //write 5 zero integers as fourCC is used
             imageOutput.write(new byte[20]);
         }
     }
 
-    private void writeFourCC(DDSImageWriterParam param) throws IOException {
+    private void writeFourCC(DDSType type, boolean writeDXT10) throws IOException {
-        if (param.isUsingDxt10()) {
+        if (writeDXT10) {
-            imageOutput.writeInt(DDSType.DXT10.value());
+            imageOutput.writeInt(DDSType.DXT10.fourCC());
-        } else if (param.getEncoderType().isFourCC())
+        }
-            imageOutput.writeInt(param.getEncoderType().getFourCC());
+        else if (type.isFourCC()) {
-
+            imageOutput.writeInt(type.fourCC());
-    }
+        }
-
+        else {
-    private void writePixelFormatFlags(DDSImageWriterParam param) throws IOException {
+            // No fourCC, custom format...
-        if (param.isUsingDxt10() || param.getEncoderType().isFourCC()) {
+            imageOutput.writeInt(0);
-            imageOutput.writeInt(DDS.PIXEL_FORMAT_FLAG_FOURCC);
-        } else {
-            imageOutput.writeInt(DDS.PIXEL_FORMAT_FLAG_RGB | (param.getEncoderType().isAlphaMaskSupported() ? DDS.PIXEL_FORMAT_FLAG_ALPHAPIXELS : 0));
         }
     }
 
-    private void writePitchOrLinearSize(int height, int width, DDSImageWriterParam param) throws IOException {
+    private void writePixelFormatFlags(DDSType type, boolean writeDXT10) throws IOException {
-        DDSEncoderType type = param.getEncoderType();
+        if (writeDXT10 || type.isFourCC()) {
-        int bitsOrBlockSize = type.getBitsOrBlockSize();
+            imageOutput.writeInt(DDS.PIXEL_FORMAT_FLAG_FOURCC);
-        if (type.isBlockCompression()) {
-            imageOutput.writeInt(((width + 3) / 4) * ((height + 3) / 4) * bitsOrBlockSize);
         } else {
-            imageOutput.writeInt(width * bitsOrBlockSize);
+            imageOutput.writeInt(DDS.PIXEL_FORMAT_FLAG_RGB | (type.rgbaMasks != null ? DDS.PIXEL_FORMAT_FLAG_ALPHAPIXELS : 0));
+        }
+    }
+
+    private void writePitchOrLinearSize(int height, int width, DDSType type) throws IOException {
+        if (type.isBlockCompression()) {
+            imageOutput.writeInt(((width + 3) / 4) * ((height + 3) / 4) * type.blockSize());
+        } else {
+            imageOutput.writeInt(width * type.blockSize());
         }
     }
 
     @Override
     public IIOMetadata getDefaultImageMetadata(ImageTypeSpecifier imageType, ImageWriteParam param) {
-        throw new UnsupportedOperationException("Direct Draw Surface does not support metadata.");
+        DDSType type = param instanceof DDSImageWriteParam
+            ? ((DDSImageWriteParam) param).type()
+            : DDSImageWriteParam.DEFAULT_TYPE;
+
+        return new DDSImageMetadata(imageType, type);
     }
 
     @Override
     public IIOMetadata convertImageMetadata(IIOMetadata inData, ImageTypeSpecifier imageType, ImageWriteParam param) {
-        throw new UnsupportedOperationException("Direct Draw Surface does not support metadata.");
+        // Nothing useful to convert here...
+        return getDefaultImageMetadata(imageType, param);
     }
 
     public static void main(String[] args) throws IOException {
-        if (args.length != 1) throw new IllegalArgumentException("Use 1 input file at a time.");
+        if (args.length != 1) {
+            throw new IllegalArgumentException("Use 1 input file at a time.");
+        }
         ImageIO.write(ImageIO.read(new File(args[0])), "dds", new MemoryCacheImageOutputStream(Files.newOutputStream(Paths.get("output.dds"))));
     }
 }

imageio/imageio-dds/src/main/java/com/twelvemonkeys/imageio/plugins/dds/DDSImageWriterParam.java

@@ -1,146 +0,0 @@
-package com.twelvemonkeys.imageio.plugins.dds;
-
-import javax.imageio.ImageWriteParam;
-import java.util.Objects;
-
-public final class DDSImageWriterParam extends ImageWriteParam {
-
-    // TODO: Rewrite to use more standard "compressionType":
-    //  See metadata format for how to create compression name based on fourCC, we probably need to change that as well (?)
-    //  At least they need to agree on what the compression names are... BC1, BC2, etc? DXT1, DXT2, etc?
-    //  Extra bit flags etc, may be set using custom methods
-
-    private final int optionalBitFlags;
-    private final DDSEncoderType encoderType;
-    private final boolean enableDxt10;
-
-    DDSImageWriterParam(int optionalBitFlags, DDSEncoderType encoderType, boolean isUsingDxt10) {
-        super();
-        canWriteCompressed = true; // always compressed
-
-        this.optionalBitFlags = optionalBitFlags;
-        this.encoderType = encoderType;
-        this.enableDxt10 = isUsingDxt10;
-    }
-
-    public static Builder builder() {
-        return new Builder();
-    }
-
-    int getOptionalBitFlags() {
-        return this.optionalBitFlags;
-    }
-
-    DDSEncoderType getEncoderType() {
-        return this.encoderType;
-    }
-
-    public boolean isUsingDxt10() {
-        return enableDxt10;
-    }
-
-    int getDxgiFormat() {
-        return getEncoderType().getDx10Format();
-    }
-
-    public static final class Builder {
-        //we use Set collection to prevent duplications of bitflag setter calls
-        private int optionalBitFlag;
-        private DDSEncoderType encoderType;
-        private boolean isUsingDxt10;
-
-        public Builder() {
-            optionalBitFlag = 0;
-            encoderType = null;
-            isUsingDxt10 = false;
-        }
-
-        /**
-         * Enable saving file as Direct3D 10+ format.
-         */
-        public Builder enableDX10() {
-            isUsingDxt10 = true;
-            return this;
-        }
-
-        /**
-         * Set the compression type to be BC1 (DXT1).
-         * If DXT10 is enabled, this will set DXGI Format to DXGI_FORMAT_BC1_UNORM.
-         */
-        public Builder formatBC1() {
-            encoderType = DDSEncoderType.BC1;
-            return setFlag(DDSFlags.DDSD_LINEARSIZE);
-        }
-
-        /**
-         * Set the compression type to be BC2 (DXT3).
-         * If DXT10 is enabled, this will set DXGI Format to DXGI_FORMAT_BC2_UNORM.
-         */
-        public Builder formatBC2() {
-            encoderType = DDSEncoderType.BC2;
-            return setFlag(DDSFlags.DDSD_LINEARSIZE);
-        }
-
-        /**
-         * Set the compression type to be BC3 (DXT5).
-         * If DXT10 is enabled, this will set DXGI Format to DXGI_FORMAT_BC3_UNORM.
-         */
-        public Builder formatBC3() {
-            encoderType = DDSEncoderType.BC3;
-            return setFlag(DDSFlags.DDSD_LINEARSIZE);
-        }
-
-        /**
-         * Set the compression type to be BC4 (ATI1).
-         * If DXT10 is enabled, This will set DXGI Format to DXGI_FORMAT_BC4_UNORM.
-         */
-        public Builder formatBC4() {
-            encoderType = DDSEncoderType.BC4;
-            return setFlag(DDSFlags.DDSD_LINEARSIZE);
-        }
-
-        /**
-         * Set the compression type to be BC5 (ATI2).
-         * This will set DXGI Format to DXGI_FORMAT_BC5_UNORM.
-         */
-        public Builder formatBC5() {
-            encoderType = DDSEncoderType.BC5;
-            return setFlag(DDSFlags.DDSD_LINEARSIZE);
-        }
-
-        public Builder setFlag(DDSFlags flag) {
-            optionalBitFlag |= flag.getValue();
-            return this;
-        }
-
-        /**
-         * Set other optional flags for the DDS Header.
-         */
-        public Builder setFlags(DDSFlags... flags) {
-            for (DDSFlags flag : flags)
-                setFlag(flag);
-            return this;
-        }
-
-        public DDSImageWriterParam build() {
-            Objects.requireNonNull(encoderType, "no DDS format specified.");
-            return new DDSImageWriterParam(optionalBitFlag, encoderType, isUsingDxt10);
-        }
-
-        public enum DDSFlags {
-            DDSD_PITCH(DDS.FLAG_PITCH),// Required when pitch is provided for an uncompressed texture.
-            DDSD_MIPMAPCOUNT(DDS.FLAG_MIPMAPCOUNT),// Required in a mipmapped texture.
-            DDSD_LINEARSIZE(DDS.FLAG_LINEARSIZE),// Required when pitch is provided for a compressed texture.
-            DDSD_DEPTH(DDS.FLAG_DEPTH);// Required in a depth texture.
-
-            private final int flag;
-            DDSFlags(int flag) {
-                this.flag = flag;
-            }
-
-            public int getValue() {
-                return flag;
-            }
-        }
-    }
-}

imageio/imageio-dds/src/main/java/com/twelvemonkeys/imageio/plugins/dds/DDSImageWriterSpi.java

@@ -23,6 +23,6 @@ public final class DDSImageWriterSpi extends ImageWriterSpiBase {
 
     @Override
     public String getDescription(Locale locale) {
-        return "Direct Draw Surface (DDS) Image Writer";
+        return "DirectDraw Surface (DDS) Image Writer";
     }
 }

imageio/imageio-dds/src/main/java/com/twelvemonkeys/imageio/plugins/dds/DDSReader.java

@@ -74,7 +74,6 @@ final class DDSReader {
     static final Order RGB_16_ORDER = new Order(11, 5, 0, -1); // no alpha | 5 red | 6 green | 5 blue
 
     private final DDSHeader header;
-    private DX10Header dxt10Header;
 
     DDSReader(DDSHeader header) {
         this.header = header;
@@ -82,18 +81,20 @@ final class DDSReader {
 
     int[] read(ImageInputStream imageInput, int imageIndex) throws IOException {
         // type
-        DDSType type = getType();
+        DDSType type = header.getType();
-        if (type == DDSType.DXT10) {
-            dxt10Header = DX10Header.read(imageInput);
-            type = dxt10Header.getDDSType();
-        }
 
         // offset buffer to index mipmap image
         byte[] buffer = null;
         for (int i = 0; i <= imageIndex; i++) {
-            int len = getLength(type, i);
+            int len = getBufferLength(type, i);
-            buffer = new byte[len];
+
-            imageInput.readFully(buffer);
+            if (i == imageIndex) {
+                buffer = new byte[len];
+                imageInput.readFully(buffer);
+            }
+            else {
+                imageInput.seek(imageInput.getStreamPosition() + len);
+            }
         }
 
         int width = header.getWidth(imageIndex);
@@ -135,82 +136,17 @@ final class DDSReader {
         }
     }
 
-    private DDSType getType() throws IIOException {
+    private int getBufferLength(DDSType type, int imageIndex) throws IIOException {
-        int flags = header.getPixelFormatFlags();
-
-        if ((flags & DDS.PIXEL_FORMAT_FLAG_FOURCC) != 0) {
-            // DXT
-            int type = header.getFourCC();
-            return DDSType.valueOf(type);
-        } else if ((flags & DDS.PIXEL_FORMAT_FLAG_RGB) != 0) {
-            // RGB
-            int bitCount = header.getBitCount();
-            int redMask = header.getRedMask();
-            int greenMask = header.getGreenMask();
-            int blueMask = header.getBlueMask();
-            int alphaMask = ((flags & 0x01) != 0) ? header.getAlphaMask() : 0; // 0x01 alpha
-            if (bitCount == 16) {
-                if (redMask == A1R5G5B5_MASKS[0] && greenMask == A1R5G5B5_MASKS[1] && blueMask == A1R5G5B5_MASKS[2] && alphaMask == A1R5G5B5_MASKS[3]) {
-                    // A1R5G5B5
-                    return DDSType.A1R5G5B5;
-                } else if (redMask == X1R5G5B5_MASKS[0] && greenMask == X1R5G5B5_MASKS[1] && blueMask == X1R5G5B5_MASKS[2] && alphaMask == X1R5G5B5_MASKS[3]) {
-                    // X1R5G5B5
-                    return DDSType.X1R5G5B5;
-                } else if (redMask == A4R4G4B4_MASKS[0] && greenMask == A4R4G4B4_MASKS[1] && blueMask == A4R4G4B4_MASKS[2] && alphaMask == A4R4G4B4_MASKS[3]) {
-                    // A4R4G4B4
-                    return DDSType.A4R4G4B4;
-                } else if (redMask == X4R4G4B4_MASKS[0] && greenMask == X4R4G4B4_MASKS[1] && blueMask == X4R4G4B4_MASKS[2] && alphaMask == X4R4G4B4_MASKS[3]) {
-                    // X4R4G4B4
-                    return DDSType.X4R4G4B4;
-                } else if (redMask == R5G6B5_MASKS[0] && greenMask == R5G6B5_MASKS[1] && blueMask == R5G6B5_MASKS[2] && alphaMask == R5G6B5_MASKS[3]) {
-                    // R5G6B5
-                    return DDSType.R5G6B5;
-                } else {
-                    throw new IIOException("Unsupported 16bit RGB image.");
-                }
-            } else if (bitCount == 24) {
-                if (redMask == R8G8B8_MASKS[0] && greenMask == R8G8B8_MASKS[1] && blueMask == R8G8B8_MASKS[2] && alphaMask == R8G8B8_MASKS[3]) {
-                    // R8G8B8
-                    return DDSType.R8G8B8;
-                } else {
-                    throw new IIOException("Unsupported 24bit RGB image.");
-                }
-            } else if (bitCount == 32) {
-                if (redMask == A8B8G8R8_MASKS[0] && greenMask == A8B8G8R8_MASKS[1] && blueMask == A8B8G8R8_MASKS[2] && alphaMask == A8B8G8R8_MASKS[3]) {
-                    // A8B8G8R8
-                    return DDSType.A8B8G8R8;
-                } else if (redMask == X8B8G8R8_MASKS[0] && greenMask == X8B8G8R8_MASKS[1] && blueMask == X8B8G8R8_MASKS[2] && alphaMask == X8B8G8R8_MASKS[3]) {
-                    // X8B8G8R8
-                    return DDSType.X8B8G8R8;
-                } else if (redMask == A8R8G8B8_MASKS[0] && greenMask == A8R8G8B8_MASKS[1] && blueMask == A8R8G8B8_MASKS[2] && alphaMask == A8R8G8B8_MASKS[3]) {
-                    // A8R8G8B8
-                    return DDSType.A8R8G8B8;
-                } else if (redMask == X8R8G8B8_MASKS[0] && greenMask == X8R8G8B8_MASKS[1] && blueMask == X8R8G8B8_MASKS[2] && alphaMask == X8R8G8B8_MASKS[3]) {
-                    // X8R8G8B8
-                    return DDSType.X8R8G8B8;
-                } else {
-                    throw new IIOException("Unsupported 32bit RGB image.");
-                }
-            } else {
-                throw new IIOException("Unsupported bit count: " + bitCount);
-            }
-        } else {
-            throw new IIOException("Unsupported YUV or LUMINANCE image.");
-        }
-    }
-
-    private int getLength(DDSType type, int imageIndex) throws IIOException {
         int width = header.getWidth(imageIndex);
         int height = header.getHeight(imageIndex);
 
         switch (type) {
             case DXT1:
-                return 8 * ((width + 3) / 4) * ((height + 3) / 4);
             case DXT2:
             case DXT3:
             case DXT4:
             case DXT5:
-                return 16 * ((width + 3) / 4) * ((height + 3) / 4);
+                return type.blockSize() * ((width + 3) / 4) * ((height + 3) / 4);
             case A1R5G5B5:
             case X1R5G5B5:
             case A4R4G4B4:
@@ -221,9 +157,9 @@ final class DDSReader {
             case X8B8G8R8:
             case A8R8G8B8:
             case X8R8G8B8:
-                return (type.value() & 0xFF) * width * height;
+                return type.blockSize() * width * height;
             default:
-                throw new IIOException("Unknown type: " + Integer.toHexString(type.value()));
+                throw new IIOException("Unknown type: " + type);
         }
     }
 

imageio/imageio-dds/src/main/java/com/twelvemonkeys/imageio/plugins/dds/DDSType.java

@@ -30,41 +30,155 @@
 
 package com.twelvemonkeys.imageio.plugins.dds;
 
+import static com.twelvemonkeys.imageio.plugins.dds.BlockCompression.*;
+import static com.twelvemonkeys.imageio.plugins.dds.DDSReader.*;
+
+/**
+ * <a href="https://learn.microsoft.com/en-us/windows/win32/direct3d10/d3d10-graphics-programming-guide-resources-block-compression#compression-algorithms">Compression Algorithms</a>
+ * <a href="https://github.com/microsoft/DirectXTK12/wiki/DDSTextureLoader#remarks">An extended Non-DX10 FourCC list</a>
+ */
 enum DDSType {
-    DXT1(0x31545844),
+    // Compressed types
-    DXT2(0x32545844),
+    DXT1('D' + ('X' << 8) + ('T' << 16) + ('1' << 24),  8, DXGI.DXGI_FORMAT_BC1_UNORM, BC1),
-    DXT3(0x33545844),
+    DXT2('D' + ('X' << 8) + ('T' << 16) + ('2' << 24), 16, DXGI.DXGI_FORMAT_BC2_UNORM, BC2),
-    DXT4(0x34545844),
+    DXT3('D' + ('X' << 8) + ('T' << 16) + ('3' << 24), 16, DXGI.DXGI_FORMAT_BC2_UNORM, BC2),
-    DXT5(0x35545844),
+    DXT4('D' + ('X' << 8) + ('T' << 16) + ('4' << 24), 16, DXGI.DXGI_FORMAT_BC3_UNORM, BC3),
-    DXT10(0x30315844),
+    DXT5('D' + ('X' << 8) + ('T' << 16) + ('5' << 24), 16, DXGI.DXGI_FORMAT_BC3_UNORM, BC3),
-    A1R5G5B5((1 << 16) | 2),
-    X1R5G5B5((2 << 16) | 2),
-    A4R4G4B4((3 << 16) | 2),
-    X4R4G4B4((4 << 16) | 2),
-    R5G6B5((5 << 16) | 2),
-    R8G8B8((1 << 16) | 3),
-    A8B8G8R8((1 << 16) | 4),
-    X8B8G8R8((2 << 16) | 4),
-    A8R8G8B8((3 << 16) | 4),
-    X8R8G8B8((4 << 16) | 4);
 
-    private final int value;
+    ATI1('A' + ('T' << 8) + ('I' << 16) + ('1' << 24),  8, DXGI.DXGI_FORMAT_BC4_UNORM, BC4), // AKA BC4U
+    BC4U('B' + ('C' << 8) + ('4' << 16) + ('U' << 24),  8, DXGI.DXGI_FORMAT_BC4_UNORM, BC4),
+    BC4S('B' + ('C' << 8) + ('4' << 16) + ('S' << 24),  8, DXGI.DXGI_FORMAT_BC4_SNORM, BC4),
+    ATI2('A' + ('T' << 8) + ('I' << 16) + ('2' << 24), 16, DXGI.DXGI_FORMAT_BC5_UNORM, BC5), // AKA BC5U
+    BC5U('B' + ('C' << 8) + ('5' << 16) + ('U' << 24), 16, DXGI.DXGI_FORMAT_BC5_UNORM, BC5),
+    BC5S('B' + ('C' << 8) + ('5' << 16) + ('S' << 24), 16, DXGI.DXGI_FORMAT_BC5_SNORM, BC5),
 
-    DDSType(int value) {
+    // Special case, see DXT10Header.dxgiFormat for real format
-        this.value = value;
+    DXT10('D' + ('X' << 8) + ('1' << 16) + ('0' << 24), -1, DXGI.DXGI_FORMAT_UNKNOWN, null),
+
+    // Custom uncompressed pixel formats
+    // TODO: Consider swapping byte order to reflect the DXGI format?
+    A1R5G5B5(2, DXGI.DXGI_FORMAT_B5G5R5A1_UNORM,    A1R5G5B5_MASKS),
+    X1R5G5B5(2, DXGI.DXGI_FORMAT_UNKNOWN,           X1R5G5B5_MASKS),
+    A4R4G4B4(2, DXGI.DXGI_FORMAT_B4G4R4A4_UNORM,    A4R4G4B4_MASKS),
+    X4R4G4B4(2, DXGI.DXGI_FORMAT_UNKNOWN,           X4R4G4B4_MASKS),
+    R5G6B5(  2, DXGI.DXGI_FORMAT_B5G6R5_UNORM,      R5G6B5_MASKS),
+    R8G8B8(  3, DXGI.DXGI_FORMAT_UNKNOWN,           R8G8B8_MASKS),
+    A8B8G8R8(4, DXGI.DXGI_FORMAT_R8G8B8A8_UNORM,    A8B8G8R8_MASKS),
+    X8B8G8R8(4, DXGI.DXGI_FORMAT_UNKNOWN,           X8B8G8R8_MASKS),
+    A8R8G8B8(4, DXGI.DXGI_FORMAT_B8G8R8A8_UNORM,    A8R8G8B8_MASKS),
+    X8R8G8B8(4, DXGI.DXGI_FORMAT_B8G8R8X8_UNORM,    X8R8G8B8_MASKS);
+
+    private final int fourCC;
+    private final int blockSize;
+    private final int dxgiFormat;
+    final BlockCompression compression;
+    final int[] rgbaMasks;
+
+    DDSType(int fourCC, int blockSize, int dxgiFormat, BlockCompression compression) {
+        this(fourCC, blockSize, dxgiFormat, compression, null);
     }
 
-    public int value() {
+    DDSType(int blockSize, int dxgiFormat, int[] rgbaMasks) {
-        return value;
+        this(0, blockSize, dxgiFormat, null, rgbaMasks);
     }
 
-    public static DDSType valueOf(int value) {
+    DDSType(int fourCC, int blockSize, int dxgiFormat, BlockCompression compression, int[] rgbaMasks) {
-        for (DDSType type : DDSType.values()) {
+        this.fourCC = fourCC;
-            if (value == type.value()) {
+        this.blockSize = blockSize;
-                return type;
+        this.dxgiFormat = dxgiFormat;
+        this.compression = compression;
+        this.rgbaMasks = rgbaMasks;
+    }
+
+    public int fourCC() {
+        return fourCC;
+    }
+
+    public int blockSize() {
+        return blockSize;
+    }
+
+    public boolean isFourCC() {
+        return fourCC != 0;
+    }
+
+    public boolean isBlockCompression() {
+        return compression != null;
+    }
+
+    public int dxgiFormat() {
+        return dxgiFormat;
+    }
+
+    public static DDSType fromFourCC(int fourCC) {
+        if (fourCC != 0) {
+            for (DDSType type : values()) {
+                if (fourCC == type.fourCC()) {
+                    return type;
+                }
             }
         }
 
-        throw new IllegalArgumentException(String.format("Unknown type: 0x%08x", value));
+        throw new IllegalArgumentException(String.format("Unknown type: 0x%08x", fourCC));
+    }
+
+    public static DDSType fromDXGIFormat(int dxgiFormat) {
+        switch (dxgiFormat) {
+            case DXGI.DXGI_FORMAT_R8G8B8A8_TYPELESS:
+            case DXGI.DXGI_FORMAT_R8G8B8A8_UNORM:
+            case DXGI.DXGI_FORMAT_R8G8B8A8_UNORM_SRGB:
+            case DXGI.DXGI_FORMAT_R8G8B8A8_UINT:
+                return A8B8G8R8; // ABGR
+
+            case DXGI.DXGI_FORMAT_B8G8R8A8_TYPELESS:
+            case DXGI.DXGI_FORMAT_B8G8R8A8_UNORM:
+            case DXGI.DXGI_FORMAT_B8G8R8A8_UNORM_SRGB:
+                return A8R8G8B8; // ARGB
+
+            case DXGI.DXGI_FORMAT_B8G8R8X8_TYPELESS:
+            case DXGI.DXGI_FORMAT_B8G8R8X8_UNORM:
+            case DXGI.DXGI_FORMAT_B8G8R8X8_UNORM_SRGB:
+                return X8R8G8B8;
+
+            case DXGI.DXGI_FORMAT_B5G5R5A1_UNORM:
+                return A1R5G5B5;
+
+            case DXGI.DXGI_FORMAT_B4G4R4A4_UNORM:
+                return A4R4G4B4;
+
+            case DXGI.DXGI_FORMAT_B5G6R5_UNORM:
+                return R5G6B5;
+
+            case DXGI.DXGI_FORMAT_BC1_TYPELESS:
+            case DXGI.DXGI_FORMAT_BC1_UNORM:
+            case DXGI.DXGI_FORMAT_BC1_UNORM_SRGB:
+                return DXT1;
+
+            case DXGI.DXGI_FORMAT_BC2_TYPELESS:
+            case DXGI.DXGI_FORMAT_BC2_UNORM:
+            case DXGI.DXGI_FORMAT_BC2_UNORM_SRGB:
+                return DXT2;
+
+            case DXGI.DXGI_FORMAT_BC3_TYPELESS:
+            case DXGI.DXGI_FORMAT_BC3_UNORM:
+            case DXGI.DXGI_FORMAT_BC3_UNORM_SRGB:
+                return DXT4;
+
+            case DXGI.DXGI_FORMAT_BC4_TYPELESS:
+            case DXGI.DXGI_FORMAT_BC4_UNORM:
+                return ATI1;
+
+            case DXGI.DXGI_FORMAT_BC4_SNORM:
+                return BC4S;
+
+            case DXGI.DXGI_FORMAT_BC5_TYPELESS:
+            case DXGI.DXGI_FORMAT_BC5_UNORM:
+                return ATI2;
+
+            case DXGI.DXGI_FORMAT_BC5_SNORM:
+                return BC5S;
+        }
+
+        throw new IllegalArgumentException("Unsupported DXGI_FORMAT: " + dxgiFormat);
     }
 }

imageio/imageio-dds/src/main/java/com/twelvemonkeys/imageio/plugins/dds/DX10DXGIFormat.java

@@ -1,50 +0,0 @@
-package com.twelvemonkeys.imageio.plugins.dds;
-
-import java.util.Arrays;
-import java.util.function.IntPredicate;
-
-/**
- * Enum that lists a certain types of DXGI Format this reader supports to read.
- *
- * <a href="https://learn.microsoft.com/en-us/windows/win32/api/dxgiformat/ne-dxgiformat-dxgi_format">DXGI Format List</a>
- */
-public enum DX10DXGIFormat {
-    BC1(DDSType.DXT1, rangeInclusive(70, 72)),
-    BC2(DDSType.DXT2, rangeInclusive(73, 75)),
-    BC3(DDSType.DXT5, rangeInclusive(76, 78)),
-    //BC7(99),
-    B8G8R8A8(DDSType.A8B8G8R8, exactly(87, 90, 91)),
-    B8G8R8X8(DDSType.X8B8G8R8, exactly(88, 92, 93)),
-    R8G8B8A8(DDSType.A8R8G8B8, rangeInclusive(27, 32));
-    private final DDSType ddsType;
-    private final IntPredicate dxgiFormat;
-
-    DX10DXGIFormat(DDSType ddsType, IntPredicate dxgiFormat) {
-        this.ddsType = ddsType;
-        this.dxgiFormat = dxgiFormat;
-    }
-
-    DDSType getCorrespondingType() {
-        return ddsType;
-    }
-
-    static DX10DXGIFormat getFormat(int value) {
-        for (DX10DXGIFormat format : values()) {
-            if (format.dxgiFormat.test(value)) return format;
-        }
-
-        throw new IllegalArgumentException("Unsupported DXGI_FORMAT : " + value);
-    }
-
-
-    /**
-     * @param acceptedValues values in DXGI Formats List, passed values are expected to be in ascending order
-     */
-    private static IntPredicate exactly(int... acceptedValues) {
-        return test -> Arrays.binarySearch(acceptedValues, test) >= 0;
-    }
-
-    private static IntPredicate rangeInclusive(int from, int to) {
-        return test -> from <= test && test <= to;
-    }
-}

imageio/imageio-dds/src/main/java/com/twelvemonkeys/imageio/plugins/dds/DX10Header.java

@@ -1,33 +0,0 @@
-package com.twelvemonkeys.imageio.plugins.dds;
-
-import javax.imageio.stream.ImageInputStream;
-import java.io.IOException;
-
-//https://learn.microsoft.com/en-us/windows/win32/direct3ddds/dds-header-dxt10
-final class DX10Header {
-    final DX10DXGIFormat dxgiFormat;
-    final int resourceDimension, miscFlag, arraySize, miscFlags2;
-
-    private DX10Header(int dxgiFormat, int resourceDimension, int miscFlag, int arraySize, int miscFlags2) {
-        this.dxgiFormat = DX10DXGIFormat.getFormat(dxgiFormat);
-        this.resourceDimension = resourceDimension;
-        if (this.resourceDimension != DDS.D3D10_RESOURCE_DIMENSION_TEXTURE2D)
-            throw new IllegalArgumentException("Resource dimension " + resourceDimension + " is not supported, expected 3.");
-        this.miscFlag = miscFlag;
-        this.arraySize = arraySize;
-        this.miscFlags2 = miscFlags2;
-    }
-
-    static DX10Header read(ImageInputStream inputStream) throws IOException {
-        int dxgiFormat = inputStream.readInt();
-        int resourceDimension = inputStream.readInt();
-        int miscFlag = inputStream.readInt();
-        int arraySize = inputStream.readInt();
-        int miscFlags2 = inputStream.readInt();
-        return new DX10Header(dxgiFormat, resourceDimension, miscFlag, arraySize, miscFlags2);
-    }
-
-    DDSType getDDSType() {
-        return dxgiFormat.getCorrespondingType();
-    }
-}

imageio/imageio-dds/src/main/java/com/twelvemonkeys/imageio/plugins/dds/DXGI.java

@@ -0,0 +1,129 @@
+package com.twelvemonkeys.imageio.plugins.dds;
+
+/**
+ * <a href="https://learn.microsoft.com/en-us/windows/win32/api/dxgiformat/ne-dxgiformat-dxgi_format">DXGI Format List</a>
+ */
+interface DXGI {
+    int DXGI_FORMAT_UNKNOWN = 0;
+    int DXGI_FORMAT_R32G32B32A32_TYPELESS = 1;
+    int DXGI_FORMAT_R32G32B32A32_FLOAT = 2;
+    int DXGI_FORMAT_R32G32B32A32_UINT = 3;
+    int DXGI_FORMAT_R32G32B32A32_SINT = 4;
+    int DXGI_FORMAT_R32G32B32_TYPELESS = 5;
+    int DXGI_FORMAT_R32G32B32_FLOAT = 6;
+    int DXGI_FORMAT_R32G32B32_UINT = 7;
+    int DXGI_FORMAT_R32G32B32_SINT = 8;
+    int DXGI_FORMAT_R16G16B16A16_TYPELESS = 9;
+    int DXGI_FORMAT_R16G16B16A16_FLOAT = 10;
+    int DXGI_FORMAT_R16G16B16A16_UNORM = 11;
+    int DXGI_FORMAT_R16G16B16A16_UINT = 12;
+    int DXGI_FORMAT_R16G16B16A16_SNORM = 13;
+    int DXGI_FORMAT_R16G16B16A16_SINT = 14;
+    int DXGI_FORMAT_R32G32_TYPELESS = 15;
+    int DXGI_FORMAT_R32G32_FLOAT = 16;
+    int DXGI_FORMAT_R32G32_UINT = 17;
+    int DXGI_FORMAT_R32G32_SINT = 18;
+    int DXGI_FORMAT_R32G8X24_TYPELESS = 19;
+    int DXGI_FORMAT_D32_FLOAT_S8X24_UINT = 20;
+    int DXGI_FORMAT_R32_FLOAT_X8X24_TYPELESS = 21;
+    int DXGI_FORMAT_X32_TYPELESS_G8X24_UINT = 22;
+    int DXGI_FORMAT_R10G10B10A2_TYPELESS = 23;
+    int DXGI_FORMAT_R10G10B10A2_UNORM = 24;
+    int DXGI_FORMAT_R10G10B10A2_UINT = 25;
+    int DXGI_FORMAT_R11G11B10_FLOAT = 26;
+    int DXGI_FORMAT_R8G8B8A8_TYPELESS = 27;
+    int DXGI_FORMAT_R8G8B8A8_UNORM = 28;
+    int DXGI_FORMAT_R8G8B8A8_UNORM_SRGB = 29;
+    int DXGI_FORMAT_R8G8B8A8_UINT = 30;
+    int DXGI_FORMAT_R8G8B8A8_SNORM = 31;
+    int DXGI_FORMAT_R8G8B8A8_SINT = 32;
+    int DXGI_FORMAT_R16G16_TYPELESS = 33;
+    int DXGI_FORMAT_R16G16_FLOAT = 34;
+    int DXGI_FORMAT_R16G16_UNORM = 35;
+    int DXGI_FORMAT_R16G16_UINT = 36;
+    int DXGI_FORMAT_R16G16_SNORM = 37;
+    int DXGI_FORMAT_R16G16_SINT = 38;
+    int DXGI_FORMAT_R32_TYPELESS = 39;
+    int DXGI_FORMAT_D32_FLOAT = 40;
+    int DXGI_FORMAT_R32_FLOAT = 41;
+    int DXGI_FORMAT_R32_UINT = 42;
+    int DXGI_FORMAT_R32_SINT = 43;
+    int DXGI_FORMAT_R24G8_TYPELESS = 44;
+    int DXGI_FORMAT_D24_UNORM_S8_UINT = 45;
+    int DXGI_FORMAT_R24_UNORM_X8_TYPELESS = 46;
+    int DXGI_FORMAT_X24_TYPELESS_G8_UINT = 47;
+    int DXGI_FORMAT_R8G8_TYPELESS = 48;
+    int DXGI_FORMAT_R8G8_UNORM = 49;
+    int DXGI_FORMAT_R8G8_UINT = 50;
+    int DXGI_FORMAT_R8G8_SNORM = 51;
+    int DXGI_FORMAT_R8G8_SINT = 52;
+    int DXGI_FORMAT_R16_TYPELESS = 53;
+    int DXGI_FORMAT_R16_FLOAT = 54;
+    int DXGI_FORMAT_D16_UNORM = 55;
+    int DXGI_FORMAT_R16_UNORM = 56;
+    int DXGI_FORMAT_R16_UINT = 57;
+    int DXGI_FORMAT_R16_SNORM = 58;
+    int DXGI_FORMAT_R16_SINT = 59;
+    int DXGI_FORMAT_R8_TYPELESS = 60;
+    int DXGI_FORMAT_R8_UNORM = 61;
+    int DXGI_FORMAT_R8_UINT = 62;
+    int DXGI_FORMAT_R8_SNORM = 63;
+    int DXGI_FORMAT_R8_SINT = 64;
+    int DXGI_FORMAT_A8_UNORM = 65;
+    int DXGI_FORMAT_R1_UNORM = 66;
+    int DXGI_FORMAT_R9G9B9E5_SHAREDEXP = 67;
+    int DXGI_FORMAT_R8G8_B8G8_UNORM = 68;
+    int DXGI_FORMAT_G8R8_G8B8_UNORM = 69;
+    int DXGI_FORMAT_BC1_TYPELESS = 70;
+    int DXGI_FORMAT_BC1_UNORM = 71;
+    int DXGI_FORMAT_BC1_UNORM_SRGB = 72;
+    int DXGI_FORMAT_BC2_TYPELESS = 73;
+    int DXGI_FORMAT_BC2_UNORM = 74;
+    int DXGI_FORMAT_BC2_UNORM_SRGB = 75;
+    int DXGI_FORMAT_BC3_TYPELESS = 76;
+    int DXGI_FORMAT_BC3_UNORM = 77;
+    int DXGI_FORMAT_BC3_UNORM_SRGB = 78;
+    int DXGI_FORMAT_BC4_TYPELESS = 79;
+    int DXGI_FORMAT_BC4_UNORM = 80;
+    int DXGI_FORMAT_BC4_SNORM = 81;
+    int DXGI_FORMAT_BC5_TYPELESS = 82;
+    int DXGI_FORMAT_BC5_UNORM = 83;
+    int DXGI_FORMAT_BC5_SNORM = 84;
+    int DXGI_FORMAT_B5G6R5_UNORM = 85;
+    int DXGI_FORMAT_B5G5R5A1_UNORM = 86;
+    int DXGI_FORMAT_B8G8R8A8_UNORM = 87;
+    int DXGI_FORMAT_B8G8R8X8_UNORM = 88;
+    int DXGI_FORMAT_R10G10B10_XR_BIAS_A2_UNORM = 89;
+    int DXGI_FORMAT_B8G8R8A8_TYPELESS = 90;
+    int DXGI_FORMAT_B8G8R8A8_UNORM_SRGB = 91;
+    int DXGI_FORMAT_B8G8R8X8_TYPELESS = 92;
+    int DXGI_FORMAT_B8G8R8X8_UNORM_SRGB = 93;
+    int DXGI_FORMAT_BC6H_TYPELESS = 94;
+    int DXGI_FORMAT_BC6H_UF16 = 95;
+    int DXGI_FORMAT_BC6H_SF16 = 96;
+    int DXGI_FORMAT_BC7_TYPELESS = 97;
+    int DXGI_FORMAT_BC7_UNORM = 98;
+    int DXGI_FORMAT_BC7_UNORM_SRGB = 99;
+    int DXGI_FORMAT_AYUV = 100;
+    int DXGI_FORMAT_Y410 = 101;
+    int DXGI_FORMAT_Y416 = 102;
+    int DXGI_FORMAT_NV12 = 103;
+    int DXGI_FORMAT_P010 = 104;
+    int DXGI_FORMAT_P016 = 105;
+    int DXGI_FORMAT_420_OPAQUE = 106;
+    int DXGI_FORMAT_YUY2 = 107;
+    int DXGI_FORMAT_Y210 = 108;
+    int DXGI_FORMAT_Y216 = 109;
+    int DXGI_FORMAT_NV11 = 110;
+    int DXGI_FORMAT_AI44 = 111;
+    int DXGI_FORMAT_IA44 = 112;
+    int DXGI_FORMAT_P8 = 113;
+    int DXGI_FORMAT_A8P8 = 114;
+    int DXGI_FORMAT_B4G4R4A4_UNORM = 115;
+    int DXGI_FORMAT_P208 = 130;
+    int DXGI_FORMAT_V208 = 131;
+    int DXGI_FORMAT_V408 = 132;
+    int DXGI_FORMAT_SAMPLER_FEEDBACK_MIN_MIP_OPAQUE = 189;
+    int DXGI_FORMAT_SAMPLER_FEEDBACK_MIP_REGION_USED_OPAQUE = 190;
+    int DXGI_FORMAT_FORCE_UINT = 0xffffffff;
+}

imageio/imageio-dds/src/main/java/com/twelvemonkeys/imageio/plugins/dds/DXT10Header.java

@@ -0,0 +1,45 @@
+package com.twelvemonkeys.imageio.plugins.dds;
+
+import javax.imageio.stream.ImageInputStream;
+import java.io.IOException;
+
+/**
+ * @see <a href="https://learn.microsoft.com/en-us/windows/win32/direct3ddds/dds-header-dxt10">DDS_HEADER_DXT10 structure</a>
+ */
+final class DXT10Header {
+    final int dxgiFormat;
+    final int resourceDimension;
+    final int miscFlag;
+    final int arraySize;
+    final int miscFlags2;
+
+    private final DDSType type;
+
+    private DXT10Header(int dxgiFormat, int resourceDimension, int miscFlag, int arraySize, int miscFlags2) {
+        type = DDSType.fromDXGIFormat(dxgiFormat); // Validates dxgiFormat
+        if (resourceDimension != DDS.D3D10_RESOURCE_DIMENSION_TEXTURE2D) {
+            throw new IllegalArgumentException(String.format("Resource dimension %d is not supported, expected: %d",
+                resourceDimension, DDS.D3D10_RESOURCE_DIMENSION_TEXTURE2D));
+        }
+
+        this.dxgiFormat = dxgiFormat;
+        this.resourceDimension = resourceDimension;
+        this.miscFlag = miscFlag;
+        this.arraySize = arraySize;
+        this.miscFlags2 = miscFlags2;
+    }
+
+    static DXT10Header read(ImageInputStream inputStream) throws IOException {
+        int dxgiFormat = inputStream.readInt();
+        int resourceDimension = inputStream.readInt();
+        int miscFlag = inputStream.readInt();
+        int arraySize = inputStream.readInt();
+        int miscFlags2 = inputStream.readInt();
+
+        return new DXT10Header(dxgiFormat, resourceDimension, miscFlag, arraySize, miscFlags2);
+    }
+
+    DDSType getType() {
+        return type;
+    }
+}

imageio/imageio-dds/src/test/java/com/twelvemonkeys/imageio/plugins/dds/DDSImageMetadataTest.java

@@ -0,0 +1,93 @@
+package com.twelvemonkeys.imageio.plugins.dds;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.awt.image.BufferedImage;
+
+import javax.imageio.ImageTypeSpecifier;
+import javax.imageio.metadata.IIOMetadataFormatImpl;
+import javax.imageio.metadata.IIOMetadataNode;
+
+import org.junit.jupiter.api.Test;
+import org.w3c.dom.NodeList;
+
+class DDSImageMetadataTest {
+    @Test
+    void standardMetadataDXT1() {
+        DDSImageMetadata metadata = createDDSImageMetadata(BufferedImage.TYPE_INT_ARGB, DDSType.DXT1);
+        IIOMetadataNode tree = (IIOMetadataNode) metadata.getAsTree(IIOMetadataFormatImpl.standardMetadataFormatName);
+
+        NodeList compressions = tree.getElementsByTagName("CompressionTypeName");
+        assertEquals(1, compressions.getLength());
+
+        IIOMetadataNode compression = (IIOMetadataNode) compressions.item(0);
+        assertEquals("DXT1", compression.getAttribute("value"));
+
+        // TODO: This should probably not have alpha...
+        NodeList alphas = tree.getElementsByTagName("Alpha");
+        assertEquals(1, alphas.getLength());
+        IIOMetadataNode alpha = (IIOMetadataNode) alphas.item(0);
+        assertEquals("nonpremultiplied", alpha.getAttribute("value"));
+    }
+
+    @Test
+    void standardMetadataA8R8G8B8() {
+        DDSImageMetadata metadata = createDDSImageMetadata(BufferedImage.TYPE_INT_ARGB, DDSType.A8R8G8B8);
+        IIOMetadataNode tree = (IIOMetadataNode) metadata.getAsTree(IIOMetadataFormatImpl.standardMetadataFormatName);
+
+        NodeList compressions = tree.getElementsByTagName("Compression");
+        assertEquals(0, compressions.getLength());
+
+        NodeList bitsPerSamples = tree.getElementsByTagName("BitsPerSample");
+        assertEquals(1, bitsPerSamples.getLength());
+        IIOMetadataNode bitsPerSample = (IIOMetadataNode) bitsPerSamples.item(0);
+        assertEquals("8 8 8 8", bitsPerSample.getAttribute("value"));
+
+        NodeList alphas = tree.getElementsByTagName("Alpha");
+        assertEquals(1, alphas.getLength());
+        IIOMetadataNode alpha = (IIOMetadataNode) alphas.item(0);
+        assertEquals("nonpremultiplied", alpha.getAttribute("value"));
+    }
+
+    @Test
+    void standardMetadataX8R8G8B8() {
+        DDSImageMetadata metadata = createDDSImageMetadata(BufferedImage.TYPE_INT_RGB, DDSType.X8R8G8B8);
+        IIOMetadataNode tree = (IIOMetadataNode) metadata.getAsTree(IIOMetadataFormatImpl.standardMetadataFormatName);
+
+        NodeList compressions = tree.getElementsByTagName("Compression");
+        assertEquals(0, compressions.getLength());
+
+        NodeList bitsPerSamples = tree.getElementsByTagName("BitsPerSample");
+        assertEquals(1, bitsPerSamples.getLength());
+        IIOMetadataNode bitsPerSample = (IIOMetadataNode) bitsPerSamples.item(0);
+        assertEquals("8 8 8 0", bitsPerSample.getAttribute("value")); // Or just 8 8 8?
+
+        NodeList alphas = tree.getElementsByTagName("Alpha");
+        assertEquals(1, alphas.getLength());
+        IIOMetadataNode alpha = (IIOMetadataNode) alphas.item(0);
+        assertEquals("none", alpha.getAttribute("value"));
+    }
+
+    @Test
+    void standardMetadataX1R5G5B5() {
+        DDSImageMetadata metadata = createDDSImageMetadata(BufferedImage.TYPE_INT_RGB, DDSType.X1R5G5B5);
+        IIOMetadataNode tree = (IIOMetadataNode) metadata.getAsTree(IIOMetadataFormatImpl.standardMetadataFormatName);
+
+        NodeList compressions = tree.getElementsByTagName("Compression");
+        assertEquals(0, compressions.getLength());
+
+        NodeList bitsPerSamples = tree.getElementsByTagName("BitsPerSample");
+        assertEquals(1, bitsPerSamples.getLength());
+        IIOMetadataNode bitsPerSample = (IIOMetadataNode) bitsPerSamples.item(0);
+        assertEquals("5 5 5 0", bitsPerSample.getAttribute("value"));  // Or just 5 5 5?
+
+        NodeList alphas = tree.getElementsByTagName("Alpha");
+        assertEquals(1, alphas.getLength());
+        IIOMetadataNode alpha = (IIOMetadataNode) alphas.item(0);
+        assertEquals("none", alpha.getAttribute("value"));
+    }
+
+    private static DDSImageMetadata createDDSImageMetadata(int bufferedImageType, DDSType ddsType) {
+        return new DDSImageMetadata(ImageTypeSpecifier.createFromBufferedImageType(bufferedImageType), ddsType);
+    }
+}

imageio/imageio-dds/src/test/java/com/twelvemonkeys/imageio/plugins/dds/DDSImageReaderTest.java

@@ -110,4 +110,6 @@ public class DDSImageReaderTest extends ImageReaderAbstractTest<DDSImageReader>
     protected List<String> getMIMETypes() {
         return Collections.singletonList("image/vnd-ms.dds");
     }
+
+
 }

imageio/imageio-dds/src/test/java/com/twelvemonkeys/imageio/plugins/dds/DDSImageWriteParamTest.java

@@ -0,0 +1,37 @@
+package com.twelvemonkeys.imageio.plugins.dds;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+import java.util.Arrays;
+
+import org.junit.jupiter.api.Test;
+
+class DDSImageWriteParamTest {
+    @Test
+    void compressionTypes() {
+        DDSImageWriteParam param = new DDSImageWriteParam();
+
+        String[] compressionTypes = param.getCompressionTypes();
+        DDSType[] values = Arrays.stream(DDSType.values())
+            .filter(DDSType::isBlockCompression)
+            .toArray(DDSType[]::new);
+
+        assertEquals(values.length + 1, compressionTypes.length);
+
+        for (int i = 0; i < values.length; i++) {
+            DDSType type = values[i];
+            assertEquals(type.name(), compressionTypes[i + 1]);
+        }
+
+        assertEquals("None", compressionTypes[0]);
+    }
+
+    @Test
+    void defaultParam() {
+        DDSImageWriteParam param = new DDSImageWriteParam();
+//        param.setCompressionMode(ImageWriteParam.MODE_EXPLICIT); // Meh...
+
+        assertEquals(DDSImageWriteParam.DEFAULT_TYPE, param.type());
+//        assertEquals(DDSImageWriterParam.DEFAULT_TYPE.name(), param.getCompressionType());
+    }
+}