how to convert a grayscale image to rgb image

how to covert a grayscale image to rgb image

Answer 1

[Walter Roberson]

cat(3, YourImage, YourImage, YourImage)

The result will be a truecolor image that happens to only use gray tones.

[amir]

Dear Walter could you please clarify the process? i didn't get how to execute the commend? many thanks

[Walter Roberson]

For example:

YourImage = rgb2gray( imread('lena.tif') );
newImage = cat(3, YourImage, YourImage, YourImage);

Answer 2

[Image Analyst]

This should also work:

rgbImage = ind2rgb(grayImage, gray(256));

though I usually use the cat() method given by Walter.

[Walter Roberson]

The cat() method will work when the grayscale image is class single or double, or uint8 or uint16, but ind2rgb() requires uint8 or uint16.

Answer 3

[DGM]

This answer covers multiple ways, depending on what your expected results are:

https://www.mathworks.com/matlabcentral/answers/812105-grayscale-to-rgb-in-matlab#answer_683765