[Android][Java] Povečanje hitrosti algoritma

public static Bitmap createSepiaToningEffect(Bitmap src, int depth, double red, double green, double blue) {
    // image size
    int width = src.getWidth();
    int height = src.getHeight();
    // create output bitmap
    Bitmap bmOut = Bitmap.createBitmap(width, height, src.getConfig());
    // constant grayscale
    final double GS_RED = 0.3;
    final double GS_GREEN = 0.59;
    final double GS_BLUE = 0.11;
    // color information
    int A, R, G, B;
    int pixel;
 
    // scan through all pixels
    for(int x = 0; x < width; ++x) {
        for(int y = 0; y < height; ++y) {
            // get pixel color
            pixel = src.getPixel(x, y);
            // get color on each channel
            A = Color.alpha(pixel);
            R = Color.red(pixel);
            G = Color.green(pixel);
            B = Color.blue(pixel);
            // apply grayscale sample
            B = G = R = (int)(GS_RED * R + GS_GREEN * G + GS_BLUE * B);
 
            // apply intensity level for sepid-toning on each channel
            R += (depth * red);
            if(R > 255) { R = 255; }
 
            G += (depth * green);
            if(G > 255) { G = 255; }
 
            B += (depth * blue);
            if(B > 255) { B = 255; }
 
            // set new pixel color to output image
            bmOut.setPixel(x, y, Color.argb(A, R, G, B));
        }
    }
 
    // return final image
    return bmOut;
}

private ColorMatrix CreateSepiaMatrix()
        {
            return new ColorMatrix(new float[][]
            {
                  new float[] {0.393f, 0.349f, 0.272f, 0, 0},
                  new float[] {0.769f, 0.686f, 0.534f, 0, 0},
                  new float[] {0.189f, 0.168f, 0.131f, 0, 0},
                  new float[] {     0,      0,      0, 1, 0},
                  new float[] {     0,      0,      0, 0, 1}
            });

            /*
            New Red   = R*.393 + G*.769 + B*.189
            New Green = R*.349 + G*.686 + B*.168
            New Blue  = R*.272 + G*.534 + B*.131
             */
        }