The goal I'm trying to achieve on my drupal 7 website is keeping an article image's border a certain size for all images (120x120) while the actual image themselves adjust according to the image style (100x100) and are middle aligned. (I'm unable to provide example images because I don't have 10 reputation points...)
So for a portrait image the height would be capped at say 100px and the width will be whatever is the aspect ratio is. Same thing in reverse with a landscape image, with the width being capped at 100px and the height being whatever the aspect ratio is.
All while the grey border stays a 120x120 block, and not changing according the image size.
Let me know if you need any code from my website to help with solving this.