How to evaluate PSNR values of multiple images by single loop according to the images sequence in directory/folder?

I have refrence images in seprate folder, and output images in another directory. Now i want to calculate the PSNR values by single loop, the code is given below

Directory = 'input\images'; 
Directory2 = 'results\images'; 
% Read images from Images folder
Imgs = dir(Directory);
Imgs2=dir(Directory2);
for j=1:length(Imgs)
    
    thisname = Imgs(j).name;
    thisname2 = Imgs2(j).name;
    thisfile = fullfile(Directory, thisname);
    thisfile2 = fullfile(Directory2, thisname2);
    try
      Img = imread(thisfile);  % try to read image
      Img2 = imread(thisfile2);
%       %Im = Img(:,:,1);
%      % Im2 = Img2(:,:,1);
%     figure, imshow(thisfile);
%       title(thisname);
%     figure, imshow(thisfile2);
%       title(thisname2);
%      % title(thisname2);
%      

[peaksnr, snr] = psnr(Img2, Img);
  
fprintf('\n The Peak-SNR value is %0.4f', peaksnr);
   catch
   end
end

my code is running smoothly and calculate me the PSNR values in single loop, but it doest give me the PSNR values in proper ordere. We mean it give us the PSNR values in shuffle order.

Answer 1

[Image Analyst]

Try adding an index so that they go into an array:

[peaksnr(j), snr(j)] = psnr(Img2, Img);

[Haseeb Hassan]

Dear Sir,

First let me thanks to your excellency, as you have been always here to respond our queries, the only reason whenever i stuck, come to matworks community and expect answers from you and Sir Walter. So I have tried the below line of code

[peaksnr(j), snr(j)] = psnr(Img2, Img);

But this gives us again the shuffled PSNR values. An image has been attached regrding the mentioned issue.

First we manually extracted the PSNR values in a sequence and then applied the mentioned code with your suggest piece of line code, but still the problem remains alive. Kindly have a look to it or if your excellency can write a precise code.

Thanking you again!

[Image Analyst]

Why are they repetitive and shuffled? If some have the same value, then the two pairs of files must be the same.

The results are stuffed into the arrays in the same order as the filenames are given by the operating system.

Don't use snr as a variable name because it's the name of a built-in function.

[Haseeb Hassan]

Values are not repetitive, the left side PSNR values of the images i have extracted one by one maunally, the right sides values "For Loop Extraction" means i extracted the PSNR values by using the loop from the mentioned code(even modified according to your suggestion). Okay let put this discussion aside. I have another query, how we add in fprintf command to give us the output along with the image name e.g "The PSNR of image 1 is xyz". Then it will be easy for me to note down PSNR values of every image respectively. Because from this loop command we are unable to jugde which PSNR value belongs to which image. Hope now you got my point.

Thank you Sir!

[Image Analyst]

Try replacing your fprintf with this:

fprintf('The Peak-SNR value between %s and %s is %0.4f\n', thisname, thisname2, peaksnr);

[Haseeb Hassan]

Thankyou sir for always being here.

[DIPTI MISHRA]

but how to get,,,mean value of all