Posterization for Blue Color

[Fred Ho]

I know how to do posterization for image processing, such as below...

public BufferedImage doPosterization (BufferedImage inputImage,
int posterizationVa lue) {
short[] posterize = new short[256];

for (int i = 0; i < 256; i++) {
posterize[i] = (short) (i - (i % posterizationVa lue));
}

BufferedImageOp op = new LookupOp(new ShortLookupTabl e(0, posterize),
null);
BufferedImage mBufferedImage = op.filter(input Image, null);
return mBufferedImage;
}

But how to do posterzation just on blue element? where the posterization value will be inputted by the user.
Thanks!

[BigDaddyLH]

Look at the other constructor of ShortLookupTabl e.