RGB image masking ....

How do I create a mask of an whole image using a defined threshold value ? The output should have a three channels(R, G, B). Could you please support me ?

[Jan]

A threshold for what? The R-channel, the intensity, the contrast?

Answer 1

[Jan]

If you want e.g. a mask for a certain level of the red channel:

Img   = rand(64, 48, 3);     % Test data
Mask  = Imd(:, :, 1) > 0.8;  % Test mask
Mask3 = cat(3, Mask, Mask, Mask);
Img(Mask3) = 0;              % Apply 3D mask: set red channels > 0.8 to 0.0