how can i quantize an image

Hi, I want to quantize an image, this image is uint8 and I want to quantize it to 16 levels and for this aim I want to use bitset, I do it but this bit dose not change? can you help me?

img=uint8(imread('lena.bmp'));
for i=1:size(img,1)
    for j=1:size(img,2)
        bitset(img(i,j),8,0);
        bitset(img(i,j),7,0);
        bitset(img(i,j),6,0);
        bitset(img(i,j),5,0);
    end
end

Answer 1

[Walter Roberson]

You have to assign the output of bitset to something.

I would suggest, by the way, that you consider bitand

img(i,j) = bitand(img(i,j), uint8(240));

You can do the whole thing without a loop:

newimg = bitand(img, uint8(240));