How can i set few pixels to a particular color(red) in a gray scale image?

The image is gray scale.If i can get a condition to select some pixels, (say for all x>100 or anything), I want those selected pixels to be of red color when i display the image. Condition doesnt matter because i have the pixel coordinates for which i want red color.Please help me with some ideas. Thankyou.

Answer 1

[Shivaputra Narke]

May be this is what you want.. close all; clear all;

a=imread('cameraman.tif');

%%% condition to find pixel location pxllocat=find(a>128);

[X, map] = gray2ind(a,255); % 255 is for 8 bit image

getLocationInMap=unique(X(pxllocat)); for i=1:length(getLocationInMap) map(i,:)=[1 0 0]; end figure;imshow(a);title('Original Image'); figure;imshow(X,map);title('Modified Image');

[Nithya]

Thankyou for the concept.