How can I convert my image to a red image

this is my code:

function redImage(app, event)

a=getappdata(0,'a');

red=a;

red(:,:,2:3)=0;

setappdata(0,'filename',red);

imshow(red,'Parent',app.UIAxes2);

end

Answer 1

[DGM]

That would work if you wanted a red image. It would even work if your input image were single-channel.

inpict = imread('cameraman.tif'); % MxNx1

inpict(:,:,2:3) = 0; % create red image by implicit expansion
imshow(inpict)

... but it wouldn't work if you wanted to do a green or blue image using the same method.

inpict(:,:,[1 3]) = 0; % create green image the same way?
imshow(inpict) % it's black because we just zeroed channel 1

See this thread:

https://www.mathworks.com/matlabcentral/answers/1876382-hi-so-im-changing-the-color-of-the-image-to-green-and-blue-but-its-not-working-one-of-them-gives-an