Question

I write an image filter in Matlab and I want to translate it to java in order to use my android application. How can I convert short or int to uint8 data format.

BTW:I know there is no type like uint8 in java.

Any help will be greatly appreciated.

Matlab:

for iX = 1:imageX
    for iY = 1:imageY
        x(1:3) = input(iX,iY,:);
        output(iX, iY, :) = uint8(p1.*x.^5 + p2.*x.^4 + p3.*x.^3 + p4.*x.^2 + p5.*x + p6);
    end
end

Java:

for (int iX = 0; iX < width; iX++) {
            for (int iY = 0; iY < height; iY++) {
                Arrays.fill(x, bitmap.getPixel(iX, iY));
                short total = 0;
                for (int i = 0; i < 3; i++) {
                    total +=p1[i] * Math.pow(x[i], 5) + p2[i]
                            * Math.pow(x[i], 4) + p3[i] * Math.pow(x[i], 3)
                            + p4[i] * Math.pow(x[i], 2) + p5[i] * x[i] + p6[i];
                }
                output.setPixel(iX, iY, total);
            }
        }

Answer 1

Don’t create total. In matlab you handle each color component separately. Do same in java:

for (int iX = 0; iX < width; iX++) {
        for (int iY = 0; iY < height; iY++) {
            Arrays.fill(x, bitmap.getPixel(iX, iY));
            // Result color components.
            int[] res = new int[3];
            short total = 0;
            for (int i = 0; i < 3; i++) {
                res[i] = p1[i] * Math.pow(x[i], 5) + p2[i]
                        * Math.pow(x[i], 4) + p3[i] * Math.pow(x[i], 3)
                        + p4[i] * Math.pow(x[i], 2) + p5[i] * x[i] + p6[i];
                // Make sure final value is in range [0, 255]
                res[i] = Math.min(255, Math.max(0, res[i]));
            }
            output.setPixel(iX, iY, Color.rgb(res[0], res[1], res[2]);
        }
    }