There lots of software for customizing image files, but most of them are not simple and user-friendly. So if you’re looking for a simple and free customizing tool for images, check this one out. ImageMagick is a tool that can convert, edit, and even help you create image files, and supports tons of image formats including jpeg, gif, png, tiff, and many more.
I have been using ImageMagick for a number of years for various tasks, both by running the tools directly from the command line, and via scripts that I use to automate image processing tasks. I have been considering writing a script that you can use to automate resizing your images for submission to the club. Please comment and let me know if you would find this useful.