I’d like to add my vote for this feature request too. I use a site where they require images to be sized to 900px on their width only for upload. That means a 6×4 portrait aspect ratio image is 1350 pixels high but a landscape image would be less tall. I would like to be able to specify the length of one side (not just the longest side) and let RAW Power size it correctly for me. Any chance that could happen?