`ind2rgb`

Converts an indexed image and its colormap to an RGB image.

Category: Graphics > Images

Syntax

RGB = ind2rgb(X, map)

Replaces each index in X by the color of the corresponding row of map.

Description

The result has one plane per color channel, so RGB(:,:,1) holds the red values of all pixels. It is the inverse of rgb2ind when no color was lost, and a convenient step before filtering color data.

Input arguments

X: Indexed image. Integer-class indices start at 0, double ones at 1.
map: Colormap, m-by-3.

Output arguments

RGB: m-by-n-by-3 double image.

Example

Look up colors

X = [1 2];
map = [1 0 0; 0 1 0];
RGB = ind2rgb(X, map);
disp(size(RGB))
disp(squeeze(RGB(1, 2, :))')

Output

     1     2     3
     0     1     0

See also

rgb2ind cmunique colormap imshow