I require aid

Does anyone know a good tool that can crop an image to exact sizes? I've been trying to cut some maps from my campaign into equal quarters because every time I put them into roll20 they clip together wrong because they fit into the tiles a certain way and I can't resize them because then the map just look bad. But I can't put the full map on roll20 in one go because there's a size limit if you don't have a paid subscription.