How to change particular pixel color of a binary image to other color?

Sir,

I have a binary image and i want to change the color of the black pixel to green. How do i do that ? Please help. Thanks in advance.

This is the binary image:

Answer 1

[Image Analyst]

Try this:

%grayImage = imread('cameraman.tif');
%binaryImage = grayImage > 128;
%subplot(1,2,1);
%imshow(binaryImage);
redAndBlueChannel = 255 * uint8(binaryImage);
greenChannel = 255 * ones(size(binaryImage), 'uint8'); % Green Everywhere.
rgbImage = cat(3, redAndBlueChannel, greenChannel, redAndBlueChannel);
%subplot(1,2,2);
%imshow(rgbImage);

Remove the % if you want to demo it using a standard MATLAB demo image.

[Image Analyst]

If you want to do it via a colormap instead of creating an RGB image, do it like this:

grayImage = imread('cameraman.tif');
binaryImage = grayImage > 128;
imshow(binaryImage);
myColorMap = [0,1,0;1,1,1]; % 0 = green, 1 = white.
colormap(myColorMap)
colorbar;

[Asif Hasan]

Thanks for reply sir but it gives me full green image all i want is that only the vessel line will be green. How do i change it? And it's a binary image where 0 represents vessels..

[Image Analyst]

It does not. You must not have a binary image. Maybe it's a RGB image. Please attach your original binary variable in a .mat file, not the JPG image that you did, which of course is 24 bit color, NOT binary.

[Asif Hasan]

Sir,

If i am not wrong it's a binary image and i am attaching the mat file. Waiting for your reply.

[Image Analyst]

MATLAB says this mat file has a structure in it with no fields. Please save the binary image in a mat file and reattach.

save('test.mat', 'binaryImage'); % binaryImage is your binary image.

The quotes are important.

[Asif Hasan]

Sorry sir my mistake.

[Image Analyst]

It works just fine. Here's proof:

s = load('binaryimage.mat')
binaryImage = s.show;
subplot(1,2,1);
imshow(binaryImage);
redAndBlueChannel = 255 * uint8(binaryImage);
greenChannel = 255 * ones(size(binaryImage), 'uint8'); % Green Everywhere.
rgbImage = cat(3, redAndBlueChannel, greenChannel, redAndBlueChannel);
subplot(1,2,2);
imshow(rgbImage);

[Asif Hasan]

Thanks sir it worked.

Answer 2

[Doug Hull]

Change colormap?

clf
im = round(rand(10));
imshow(im)
colormap([0 1 0; 1 1 1])

[Asif Hasan]

Sir please explain i can't understand.