RFR: 8364583: ColorConvertOp fails for CMYK → RGB conversion

[Harshitha Onkar]

On Mon, 3 Nov 2025 19:00:45 GMT, Sergey Bylokhov <serb at openjdk.org> wrote:

>> fromCIEXYZ is defined on ColorSpace, not ICC_ColorSpace.
>> 
>> It requires 3 (or more) components, and then dstColorSpace will return an array of colors in its own colorspace.
>> The dstColor parameter is always created with at least 3 components based on the dstNumComp
>> And if there's no bug in dstColorSpace it should return an array of the right length for itself.
>> So if there's a bug it isn't obvious to me.
>
> Seems the destination handles it properly; I tested it with the following example:
> 
> import java.awt.Transparency;
> import java.awt.color.ColorSpace;
> import java.awt.image.BufferedImage;
> import java.awt.image.ColorConvertOp;
> import java.awt.image.ComponentColorModel;
> import java.awt.image.DataBuffer;
> import java.awt.image.WritableRaster;
> 
> import static java.awt.color.ColorSpace.TYPE_2CLR;
> import static java.awt.color.ColorSpace.TYPE_FCLR;
> import static java.awt.color.ColorSpace.TYPE_GRAY;
> 
> public final class TestCCP {
> 
>     private static final int WIDTH = 10;
>     private static final int HEIGHT = 10;
> 
>     private static class CustomColorSpace extends ColorSpace {
>         private final int numComponents;
> 
>         private CustomColorSpace(int type, int numComponents) {
>             super(type, numComponents);
>             this.numComponents = numComponents;
>         }
> 
>         @Override
>         public float[] toRGB(float[] colorvalue) {
>             return new float[3];
>         }
> 
>         @Override
>         public float[] fromRGB(float[] rgbvalue) {
>             return new float[numComponents];
>         }
> 
>         @Override
>         public float[] toCIEXYZ(float[] colorvalue) {
>             return new float[3];
>         }
> 
>         @Override
>         public float[] fromCIEXYZ(float[] colorvalue) {
>             return new float[numComponents];
>         }
>     }
> 
>     private static final ColorSpace[] CS = {
>             ColorSpace.getInstance(ColorSpace.CS_CIEXYZ),
>             ColorSpace.getInstance(ColorSpace.CS_GRAY),
>             ColorSpace.getInstance(ColorSpace.CS_LINEAR_RGB),
>             ColorSpace.getInstance(ColorSpace.CS_PYCC),
>             ColorSpace.getInstance(ColorSpace.CS_sRGB),
>             new CustomColorSpace(TYPE_GRAY, 1),
>             new CustomColorSpace(TYPE_2CLR, 2),
>             new CustomColorSpace(TYPE_FCLR, 15)
>     };
> 
>     public static void main(String[] args) {
>         for (ColorSpace srcCS : CS) {
>             for (ColorSpace fromCS : CS) {
>                 for (ColorSpace toCS : CS) {
>                     for (ColorSpace dstCS : CS) {
>                         BufferedImage src = createTestImage(srcCS);
>                         BufferedImage dst = createTestImage(dstCS);
> 
>                         new ColorConvertOp(fromCS, toCS, null).filter(src, dst);
>                     }
>                 }
>             }
>         }
>     }
> 
>     private static BufferedImage createTestImage(ColorSpace cs) {
>         ComponentColorModel cm = new ComponentColorModel(cs, false, false,...

@mrserb @prrace

Are we testing the else block - the one for **"possible non-ICC src, possible CSList, possible non-ICC dst"**  with the test provided by Sergey?

Ln#872 in the else block has a similar line `color = srcCM.getNormalizedComponents(spixel, color, 0);` and the above test runs fine if normComponents is set to either color or null.

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PR Review Comment: https://git.openjdk.org/jdk/pull/27785#discussion_r2492077834