How to compute three values of PSNR one for each channel, using RGB image?

I want to compute PSNR of a watermarked RGB image and original RGB Image. Please help it's for my project.

Answer 1

[Image Analyst]

Split the image up into different color channels and use psnr() on each channel:

% Extract the individual red, green, and blue color channels.
redChannel = rgbImage(:, :, 1);
greenChannel = rgbImage(:, :, 2);
blueChannel = rgbImage(:, :, 3);
% Extract also for watermarked image, then compute PSNR:
psnrRed = pnr(redChannel, redChannelWatermarked);
psnrGreen = pnr(greenChannel , greenChannelWatermarked);
psnrBlue = pnr(blueChannel , blueChannelWatermarked);

[Aniket Paranjpe]

Thanks a lot, I will give it a try

[Aniket Paranjpe]

ya,the code worked but I want to want to find overall PSNR value of combined RGB channels?how do i do that? please help @ImageAnalyst

[Image Analyst]

 Why not just average them?

[Aniket Paranjpe]

thankyou so much @ImageAnalyst