I am currently working on a website, which has 1,000's of Product Images. All of these images were uploaded, without being optimized accordingly. For instance, most of the Product Images were uploaded with 5000px by 3000px dimensions which is far too large.
I have downloaded these Product Images to my computer, to start resizing them. Rather than manually do this, as it would simply take forever, I have setup my Photoshop to automate all of the resizing for me.
Furthermore, it would take forever to sift through the various Folders, as to pull out the original images to resize.
Instead, I was hoping to simply get Photoshop to resize every single Product Image in all of the Folders by 600px by 400px. Of course, this would also resize the various Thumbnail Images as well as the other image sizes WordPress creates upon the original image being uploaded.
Could I simply use the above approach, transfer the images back to WordPress via FTP and as long as I keep the file names the same for the various resizes images that WordPress creates, could I simply select 'Regenerate Thumbnails' and would WordPress delete their own resized images (which would now be 600px by 400px) and then replace them all with the correct sizes of 150px by 150px and 250px by 250px etc?