How to compare the saved names of two images stored in different folders ?

I have 12 input images in the inputImages folder with names 001_in.png, 002_in.png ..... 012_in.png. Also I have the ground truths of these images 001_GT.png, 002_GT.png ... 012_GT.png in another folder named GroundTruth. I want to read and display these 12 images and for each of these 12 images, I have to calculate the PSNR value with respect to the ground truth stored in the GroundTruth folder. How will I get the ground truth for a particular input image ? Here's my code. I have tried to retrieve the image names and compare them. But, I am getting name1 = * , name 2 = * , last= 1×0 empty char array.

location1='G:\MTech\InputImages\*.png';
ds1=imageDatastore(location1)
while(hasdata(ds1))
    I=read(ds1);
    figure,imshow(I),title('Input Image');

    [filepath1,name1,ext1] = fileparts(location1) 
    underlineLocation1 = strfind(name1, '_')
    first = name1(1:underlineLocation1-1)   %Getting the image name upto underscore

    location2='G:\MTech\GroundTruth\*.png';
    ds2=imageDatastore(location2)
    while(hasdata(ds2))
        ref=read(ds2);
        figure,imshow(ref),title('Ground Truth');
        [filepath2,name2,ext2] = fileparts(location2)
        underlineLocation2 = strfind(name2, '_')
        last = name2(1:underlineLocation2-1)
        if first==last
            [peaksnr, snr] = psnr(I, ref);  
            fprintf('\n The Peak-SNR value of final output is %0.4f', peaksnr);
        end
    end    
end

Answer 1

[Stephen23]

I don't think imageDatastore particularly helps in this case. Something like this:

P1 = 'G:\MTech\InputImages';
P2 = 'G:\MTech\GroundTruth';
for k = 1:12
    F1 = sprintf('%03u_in.png',k);
    F2 = sprintf('%03u_GT.png',k);
    im = imread(fullfile(P1,F1));
    rf = imread(fullfile(P2,F2));
    [peaksnr,snr] = psnr(im,rf);
    fprintf('\n The Peak-SNR value of final output is %0.4f', peaksnr);
end

[Aiswarya C B]

Thank you so much..! This worked...

Answer 2

[Thiago Henrique Gomes Lobato]

You have a couple of errors in your code. Firstly to compare strings you must use the strcmp function, so

if strcmp(first,last)

instead of

if first==last

Second you're using the "fileparts" function in your image folder, not in the image that was actually loaded. By read you should also get the info and, from the info, get your file name (check here ):

[ref,info]=read(ds2);
figure,imshow(ref),title('Ground Truth');
[filepath2,name2,ext2] = fileparts(info.Filename)

[Aiswarya C B]

Thank you so much for your answer.. This helped me to fix errors..