how to identify grayscale image as an RGB image

I am working on grayscale image as input image to cnn network that take RGB image how I can identify grayscale image as an

RGB

Answer 1

[Sulaymon Eshkabilov]

You can convert a grayscale image into RGB but it wont have a color anyhow, eg:

RGB = cat(3, gray_IMAGE, gray_IMAGE, gray_IMAGE);
imwrite(RGB, OUT_FileName);

[malak alsmadi]

thank for your help

[Walter Roberson]

%more efficiently
RGB = gray_IMAGE(:,:,[1 1 1]);

Answer 2

[Walter Roberson]

CNN are fed by data stores not by individual images. The recommended practice is to use an augmented image data store. Those permit you to specify the required image size and whether the image should be automatically converted to rgb or to gray. So just by adding the call to the augmented store creation and passing the augmented store instead of the image store, the size and color are automatically fixed up for you.

Answer 3

[Sulaymon Eshkabilov]

Grayscale image has one channel and RGB has three channels. How to distinguish them is to use size() fcn.

D = imread(ImageFile1);   % RGB
[R1, C1, Channel]=size(D);   Channel = 3
D = imread(ImageFile2);   % Grayscale
[R2, C2, Channel2]=size(D);  Channel2 = 1

[malak alsmadi]

are there any way to save grayscale image as a RGB?