#501: Fix for TYPE_USHORT_555/565_RGB, ColorModel now 16 bits

(cherry picked from commit 42e17f20632ab55466687d2fb98e8f597e199aab)

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

@@ -54,6 +54,28 @@ public final class ImageTypeSpecifiers {
     private ImageTypeSpecifiers() {}
 
     public static ImageTypeSpecifier createFromBufferedImageType(final int bufferedImageType) {
+        switch (bufferedImageType) {
+            // ImageTypeSpecifier unconditionally uses bits == 32, we'll use a workaround for the USHORT types
+            case BufferedImage.TYPE_USHORT_565_RGB:
+                return createPacked(ColorSpace.getInstance(ColorSpace.CS_sRGB),
+                        0xF800,
+                        0x07E0,
+                        0x001F,
+                        0x0,
+                        DataBuffer.TYPE_USHORT,
+                        false);
+
+            case BufferedImage.TYPE_USHORT_555_RGB:
+                return createPacked(ColorSpace.getInstance(ColorSpace.CS_sRGB),
+                        0x7C00,
+                        0x03E0,
+                        0x001F,
+                        0x0,
+                        DataBuffer.TYPE_USHORT,
+                        false);
+            default:
+        }
+
         return ImageTypeSpecifier.createFromBufferedImageType(bufferedImageType);
     }
 
@@ -147,21 +169,21 @@ public final class ImageTypeSpecifiers {
 
         int numEntries = 1 << bits;
 
-        byte[] arr = new byte[numEntries];
+        byte[] r = new byte[numEntries];
-        byte[] arg = new byte[numEntries];
+        byte[] g = new byte[numEntries];
-        byte[] arb = new byte[numEntries];
+        byte[] b = new byte[numEntries];
 
         // Scale array values according to color profile..
         for (int i = 0; i < numEntries; i++) {
             float[] gray = new float[]{i / (float) (numEntries - 1)};
             float[] rgb = colorSpace.toRGB(gray);
 
-            arr[i] = (byte) (rgb[0] * 255);
+            r[i] = (byte) (rgb[0] * 255);
-            arg[i] = (byte) (rgb[1] * 255);
+            g[i] = (byte) (rgb[1] * 255);
-            arb[i] = (byte) (rgb[2]* 255);
+            b[i] = (byte) (rgb[2] * 255);
         }
 
-        ColorModel colorModel = new IndexColorModel(bits, numEntries, arr, arg, arb);
+        ColorModel colorModel = new IndexColorModel(bits, numEntries, r, g, b);
         SampleModel sampleModel = new MultiPixelPackedSampleModel(dataType, 1, 1, bits);
 
         return new ImageTypeSpecifier(colorModel, sampleModel);

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

@@ -61,10 +61,21 @@ public class ImageTypeSpecifiersTest {
     @Test
     public void testCreateFromBufferedImageType() {
         for (int type = BufferedImage.TYPE_INT_RGB; type < BufferedImage.TYPE_BYTE_INDEXED; type++) {
-            assertEquals(
+            ImageTypeSpecifier expected;
-                    ImageTypeSpecifier.createFromBufferedImageType(type),
+
-                    ImageTypeSpecifiers.createFromBufferedImageType(type)
+            switch (type) {
-            );
+                // Special handling for USHORT_565 and 555, due to bug in ImageTypeSpecifier for these types (DirectColorModel is 32 bits)
+                case BufferedImage.TYPE_USHORT_565_RGB:
+                    expected = createPacked(sRGB, DCM_565_RED_MASK, DCM_565_GRN_MASK, DCM_565_BLU_MASK, 0, DataBuffer.TYPE_USHORT, false);
+                    break;
+                case BufferedImage.TYPE_USHORT_555_RGB:
+                    expected = createPacked(sRGB, DCM_555_RED_MASK, DCM_555_GRN_MASK, DCM_555_BLU_MASK, 0, DataBuffer.TYPE_USHORT, false);
+                    break;
+                default:
+                    expected = ImageTypeSpecifier.createFromBufferedImageType(type);
+            }
+
+            assertEquals(expected, ImageTypeSpecifiers.createFromBufferedImageType(type));
         }
     }
 
@@ -119,7 +130,7 @@ public class ImageTypeSpecifiersTest {
 
         // Extra: Make sure color models bits is actually 16 (ImageTypeSpecifier equivalent returns 32)
         assertEquals(16, ImageTypeSpecifiers.createPacked(sRGB, DCM_565_RED_MASK, DCM_565_GRN_MASK, DCM_565_BLU_MASK, 0, DataBuffer.TYPE_USHORT, false).getColorModel().getPixelSize());
-   }
+    }
 
     @Test
     public void testCreatePacked8() {
@@ -531,6 +542,7 @@ public class ImageTypeSpecifiersTest {
 
     @Test
     public void testCreatePackedGrayscale1() {
+        // TODO: Fails on Java 11, because IndexColorModel now has an overloaded equals that actually tests the color entries
         assertEquals(
                 ImageTypeSpecifier.createGrayscale(1, DataBuffer.TYPE_BYTE, false),
                 ImageTypeSpecifiers.createPackedGrayscale(GRAY, 1, DataBuffer.TYPE_BYTE)
@@ -539,6 +551,7 @@ public class ImageTypeSpecifiersTest {
 
     @Test
     public void testCreatePackedGrayscale2() {
+        // TODO: Fails on Java 11, because IndexColorModel now has an overloaded equals that actually tests the color entries
         assertEquals(
                 ImageTypeSpecifier.createGrayscale(2, DataBuffer.TYPE_BYTE, false),
                 ImageTypeSpecifiers.createPackedGrayscale(GRAY, 2, DataBuffer.TYPE_BYTE)
@@ -546,7 +559,8 @@ public class ImageTypeSpecifiersTest {
     }
 
     @Test
-    public void testCreatePackedGrayscale4() {
+    public void testCreatePackedGrayscale4() throws Exception {
+        // TODO: Fails on Java 11, because IndexColorModel now has an overloaded equals that actually tests the color entries
         assertEquals(
                 ImageTypeSpecifier.createGrayscale(4, DataBuffer.TYPE_BYTE, false),
                 ImageTypeSpecifiers.createPackedGrayscale(GRAY, 4, DataBuffer.TYPE_BYTE)