How to input image to a CNN regression ?

I have 7000 images and I want to give them to CNN regression to give me RMSE chart as an output . The problem is I can noot feed my images as input , I have alredy searched a lot ,none of them were useful for example :

imds = imageDatastore(fullfile(path, categories), 'LabelSource', 'foldernames');

tbl = countEachLabel(imds);

I tried it but does not work .

So is there anyone that had experience and practically help , and give me an answer ?

In regression CNN ,is it possible use imagedatastore ? how ? Labeling needs ?