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Commit 6310160c authored by Daniel Solomon's avatar Daniel Solomon
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Add a public chromatic adaptation API to ColorSpace 

This change adds a public version of ColorSpace.chromaticAdaptation(),
so that chromatic adaptation can be done on independent CIE xyY or XYZ
coordinates without the involvement of ColorSpace.Rgb.

Test: cts-tradefed run singleCommand cts-dev --module CtsGraphicsTestCases --test android.graphics.cts.ColorSpaceTest
Bug 116516917

Change-Id: I73c33750c343301bed4bb018c351d87c5043b59b
parent 9ebc59e9

api/current.txt

+1 −0
Original line number Diff line number Diff line
@@ -13687,6 +13687,7 @@ package android.graphics { 
  public abstract class ColorSpace {

    method public static android.graphics.ColorSpace adapt(android.graphics.ColorSpace, float[]);

    method public static android.graphics.ColorSpace adapt(android.graphics.ColorSpace, float[], android.graphics.ColorSpace.Adaptation);

    method public static float[] chromaticAdaptation(android.graphics.ColorSpace.Adaptation, float[], float[]);

    method public static android.graphics.ColorSpace.Connector connect(android.graphics.ColorSpace, android.graphics.ColorSpace);

    method public static android.graphics.ColorSpace.Connector connect(android.graphics.ColorSpace, android.graphics.ColorSpace, android.graphics.ColorSpace.RenderIntent);

    method public static android.graphics.ColorSpace.Connector connect(android.graphics.ColorSpace);

graphics/java/android/graphics/ColorSpace.java

+34 −0
Original line number Diff line number Diff line
@@ -1778,6 +1778,40 @@ public abstract class ColorSpace { 
        return mul3x3(inverse3x3(matrix), mul3x3Diag(LMS, matrix));

    }



    /**

     * <p>Computes the chromatic adaptation transform from the specified

     * source white point to the specified destination white point.</p>

     *

     * <p>The transform is computed using the von Kries method, described

     * in more details in the documentation of {@link Adaptation}. The

     * {@link Adaptation} enum provides different matrices that can be

     * used to perform the adaptation.</p>

     *

     * @param adaptation The adaptation method

     * @param srcWhitePoint The white point to adapt from

     * @param dstWhitePoint The white point to adapt to

     * @return A 3x3 matrix as a non-null array of 9 floats

     */

    @NonNull

    @Size(9)

    public static float[] chromaticAdaptation(@NonNull Adaptation adaptation,

            @NonNull @Size(min = 2, max = 3) float[] srcWhitePoint,

            @NonNull @Size(min = 2, max = 3) float[] dstWhitePoint) {

        float[] srcXyz = srcWhitePoint.length == 3 ?

            Arrays.copyOf(srcWhitePoint, 3) : xyYToXyz(srcWhitePoint);

        float[] dstXyz = dstWhitePoint.length == 3 ?

            Arrays.copyOf(dstWhitePoint, 3) : xyYToXyz(dstWhitePoint);



        if (compare(srcXyz, dstXyz)) {

            return new float[] {

                1.0f, 0.0f, 0.0f,

                0.0f, 1.0f, 0.0f,

                0.0f, 0.0f, 1.0f

            };

        }

        return chromaticAdaptation(adaptation.mTransform, srcXyz, dstXyz);

    }



    /**

     * Implementation of the CIE XYZ color space. Assumes the white point is D50.

     */