My quick, easy and inexpensive approach is to simply crop the digital image using Photoshop (or any of dozens of other image-editing applications), then tile a page in either word or powerpoint with the 2x2 image and print it on decent photopaper at high-resolution on an inkjet. I cut out what I need, and then slide the sheet with the remaining images into my carry-on (usually outer pocket to keet it flat). Then, whenever I need visa pix, or whatever, when I'm traveling (or even at home), they're at my fingertips. I've used hundreds of these images for visas around the world with never a problem.