How to converting RGBa (m x n x 4) .tif image to RGB (m x n x 3) .tif

After help on my previous question, I have found that some images I want to crop (using imcrop) have been converted to RGBa due to some previous operations in paint.net (I flattened the images but still can't remove the Alpha). I thought they might be cmyk and tried a conversion I found but this gave a weird reversed image so thus I am pretty sure I have RGBa.

Does anyone have any code to convert my images within my cropping function? I have spent hours searching but to no avail.

Many thanks

Answer 1

[Image Analyst]

Why can't you just do

% Extract only channels 1, 2, & 3.
rgbImage = rgbImage(:,:,1:3);

??? What do you mean you "Flattened" the image? Can you attach your image so we can try stuff?

[Zander]

I was using two layers (and hence some transparency) in Paint.net. Afterwards I 'flattened' it to remove the layers (the cause of it changing to RGBa). But it didn't remove that extra part of the image matrix.

I can't seem to attach the image properly as it is a .tif. I must seem like a real idiot!

I've changed the file name to include a . jpg and it seemed to attach ok. Just remove that bit.

Thanks

[Zander]

Just tried what you said... it worked!!!! I tried that before but being the noob I am, I was only extracting one channel at a time so came out as grayscale of one colour value.

You've saved my bacon! Thanks