fix #62 https://github.com/jai-imageio/jai-imageio-core/issues/62

src/main/java/com/github/jaiimageio/impl/plugins/tiff/TIFFExtraSamplesColorModel.java

@@ -0,0 +1,60 @@
+package com.github.jaiimageio.impl.plugins.tiff;
+
+import java.awt.color.ColorSpace;
+import java.awt.image.ComponentColorModel;
+import java.awt.image.ComponentSampleModel;
+import java.awt.image.SampleModel;
+import java.awt.image.WritableRaster;
+import java.awt.image.DataBuffer;
+
+public class TIFFExtraSamplesColorModel extends ComponentColorModel {
+
+    private final int numComponents;
+
+    private final int componentSize;
+
+    public TIFFExtraSamplesColorModel(ColorSpace colorSpace,
+                                      int[] bits,
+                                      boolean hasAlpha,
+                                      boolean isAlphaPremultiplied,
+                                      int transparency,
+                                      int transferType,
+                                      int extraComponents) {
+        super(colorSpace, bits, hasAlpha, isAlphaPremultiplied, transparency, transferType);
+        this.numComponents = colorSpace.getNumComponents() + (hasAlpha ? 1 : 0) + extraComponents;
+        this.componentSize = DataBuffer.getDataTypeSize(transferType);
+    }
+
+    @Override
+    public int getNumComponents() {
+        return numComponents;
+    }
+
+    @Override
+    public int getComponentSize(int componentIdx) {
+        return componentSize;
+    }
+
+    @Override
+    public boolean isCompatibleSampleModel(SampleModel sm) {
+        // Must have the same number of components
+        return (sm instanceof ComponentSampleModel) && numComponents == sm.getNumBands() && transferType == sm.getTransferType();
+    }
+
+    @Override
+    public WritableRaster getAlphaRaster(WritableRaster raster) {
+        if (!hasAlpha()) {
+            return null;
+        }
+
+        int x = raster.getMinX();
+        int y = raster.getMinY();
+        int[] band = new int[] {getAlphaComponent()};
+
+        return raster.createWritableChild(x, y, raster.getWidth(), raster.getHeight(), x, y, band);
+    }
+
+    private int getAlphaComponent() {
+        return super.getNumComponents() - 1;
+    }
+}

src/main/java/com/github/jaiimageio/impl/plugins/tiff/TIFFImageReader.java

@@ -765,24 +765,41 @@ public Iterator getImageTypes(int imageIndex) throws IIOException {
                 int numBands = smRaw.getNumBands();
                 int numComponents = iccColorSpace.getNumComponents();
 
+                int extraSamplesLength = 0;
+
+                if (extraSamples != null) {
+                    extraSamplesLength = extraSamples.length;
+                }
+
                 // Replace the ColorModel with the ICC ColorModel if the
                 // numbers of samples and color components are amenable.
-                if(numBands == numComponents ||
-                   numBands == numComponents + 1) {
+                if(numBands == numComponents + extraSamplesLength ||
+                        numBands == numComponents + 1 + extraSamplesLength) {
                     // Set alpha flags.
-                    boolean hasAlpha = numComponents != numBands;
+                    boolean hasAlpha = numComponents + extraSamplesLength != numBands;
                     boolean isAlphaPre =
                         hasAlpha && cmRaw.isAlphaPremultiplied();
 
                     // Create a ColorModel of the same class and with
                     // the same transfer type.
-                    ColorModel iccColorModel =
-                        new ComponentColorModel(iccColorSpace,
-                                                cmRaw.getComponentSize(),
-                                                hasAlpha,
-                                                isAlphaPre,
-                                                cmRaw.getTransparency(),
-                                                cmRaw.getTransferType());
+                    ColorModel iccColorModel = null;
+                    if (extraSamplesLength == 0) {
+                        iccColorModel =
+                                new ComponentColorModel(iccColorSpace,
+                                        cmRaw.getComponentSize(),
+                                        hasAlpha,
+                                        isAlphaPre,
+                                        cmRaw.getTransparency(),
+                                        cmRaw.getTransferType());
+                    } else {
+                        iccColorModel = new TIFFExtraSamplesColorModel(iccColorSpace,
+                                cmRaw.getComponentSize(),
+                                hasAlpha,
+                                isAlphaPre,
+                                cmRaw.getTransparency(),
+                                cmRaw.getTransferType(),
+                                extraSamplesLength);
+                    }
 
                     // Prepend the ICC profile-based ITS to the List. The
                     // ColorModel and SampleModel are guaranteed to be