Utils.java 文件源码

static Bitmap contrastBitmap(Bitmap bitmap, float contrast) {
    float[] colorTransform = new float[]{
            contrast, 0, 0, 0, 0,
            0, contrast, 0, 0, 0,
            0, 0, contrast, 0, 0,
            0, 0, 0, 1, 0};

    ColorMatrix colorMatrix = new ColorMatrix();
    colorMatrix.setSaturation(0f);
    colorMatrix.set(colorTransform);

    ColorMatrixColorFilter colorFilter = new ColorMatrixColorFilter(colorMatrix);
    Paint paint = new Paint();
    paint.setColorFilter(colorFilter);

    Bitmap resultBitmap = bitmap.copy(Bitmap.Config.ARGB_8888, true);
    Canvas canvas = new Canvas(resultBitmap);
    canvas.drawBitmap(resultBitmap, 0, 0, paint);

    return resultBitmap;
}