I had a need for a streamlined thumbnail generator for a project.
I whipped this up the past couple days using python and the pillow library.
This is alpha software, but works okay.
It is very simple.
Input your max pixel size, select directory then process the files.
It will create a folder of resized images in a thumbnail subdirectory keeping the aspect ratio and using the pixel number as the largest edge.
I know you can do this with gimp scripts or photoshop, but this is lightweight, the logic can be pulled for other projects and I learned a bit about tkinter and guis.
I have tested this in linux and windows, don’t have a mac, so YMMV.
In theory it’s gonna be faster because the check is done by fast OS code rather than python. In practice… don’t bother. I don’t think you’ll notice any difference unless you’re batch creating thousands of directories.
In general python follows the “it’s easier to ask for forgiveness than permission” approach: Checking ahead of time should be avoided. If something goes wrong just catch the exception and deal with it later.