Question

Matlab Version : 7.8.0

I am reading a bmp file in matlab by using imread function –

i = imread('lena.bmp');

now i want to convert this i matrix into gif format. But since we don’t have color map table, how could we do so.

is there a way to generate map vector from the image?

Answer 1

The trick is using rgb2ind:

 [x,map]=rgb2ind(i,256);
 imwrite(x,map,'C:\test.gif');

I assumed that you want to use 256 colors in your color map. You can play with it to create more/less color quantization vs. file size.