Change the black of grayscale image into color

Hallo I gernerated with "bwperim" borders around my particles and switched them to black instead of white with a black background.

I would like to visualize the difference between multiple images by diffrent colors. Right now all the images are black and white.

how can I change the black sourrounding into a diffrent color for each picture?

Answer 1

[Image Analyst]

Threshold or somehow segment your images to get a mask of the "black" parts, then use

rgbImage = imoverlay(grayImage, mask, yourColor);

where yourColor is a 3 element array where each number of the fraction from black to bright for red, green, and blue, like [0.3, 0.6, 0.9] or whatever.

[Markus Kokot]

Thank you very much :) it works!

[Image Analyst]

Then can you please "Accept this answer"? Thanks in advance.

Answer 2

[Walter Roberson]

mask = ~YourLogicalMap;
MapR = mask .* ColorForRed;
MapG = mask .* ColorForGreen;
MapB = mask .* ColorForBlue;
MapRGB = cat(3, MapR, MapG, MapB);