How to put or replace color in rgb/greyscale picture
6 views (last 30 days)
Show older comments
Ravin Rayeok
on 29 Feb 2020
Commented: Ravin Rayeok
on 29 Feb 2020
Hello!
Need some assistance here
Anyone knows how to put the blue color as presented in these pictures below?
Seems like the bubbles blobs (White/grey) has the same rgb value to the other non-bubble area. Black blobs are pores.
![](https://www.mathworks.com/matlabcentral/answers/uploaded_files/274350/image.jpeg)
![](https://www.mathworks.com/matlabcentral/answers/uploaded_files/274351/image.jpeg)
2 Comments
Image Analyst
on 29 Feb 2020
Can you explain in words, what properties the blue regions of the gray surround have that the gray regions don't? And why do you want the blue but don't want the gray?
Accepted Answer
Image Analyst
on 29 Feb 2020
Try this:
rgbImage = imread('image.jpeg');
subplot(2, 1, 1);
imshow(rgbImage);
% Extract the individual red, green, and blue color channels.
redChannel = rgbImage(:, :, 1);
greenChannel = rgbImage(:, :, 2);
blueChannel = rgbImage(:, :, 3);
% Get the yellow mask
yellowMask = redChannel > 128 & greenChannel > 128;
% Get the white mask
whiteMask = redChannel > 128 & greenChannel > 128 & blueChannel > 128;
% Make yellow mask green
redChannel(yellowMask) = 0;
greenChannel(yellowMask) = 255;
blueChannel(yellowMask) = 0;
% Make the white mask blue
redChannel(whiteMask) = 0;
greenChannel(whiteMask) = 0;
blueChannel(whiteMask) = 255;
% Recombine separate color channels into a single, true color RGB image.
rgbImage2 = cat(3, redChannel, greenChannel, blueChannel);
subplot(2, 1, 2);
imshow(rgbImage2);
![](https://www.mathworks.com/matlabcentral/answers/uploaded_files/274383/image.png)
More Answers (0)
See Also
Products
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!