Many of the interface screens, and the gameplay for that matter, in Puppy Hunt involve full screen background images. I wanted a quick and easy way to create these images, and see exactly what they would look like on the various screen sizes.
So, in Photoshop, I started with an assumed iPad Retina screen resolution. It makes sense that it would be double the current iPad’s resolution, just like Apple did with the iPhone Retina screen. So we start out at 1536 x 2048 for the iPad Retina, then scale down to 768 x 1024 for the iPad. Then we go to 640 x 960 for the iPhone Retina, and finally 320 x 480 for the original iPhone screen. For both the iPhone Retina and the iPhone screen sizes, we crop some to account for the difference in ratios to length/width.
Also, all of the scaled down versions are slightly oversized (and cropped) because you will sometimes get some transparency added to the edges by Photoshop’s scaling algorithms. So keep this in mind when creating your original background. Any borders around the edges that you want shouldn’t be created inside the “Original” smart object, but should instead be tailored for each resolution in the main file.
Here are the photoshop files in landscape, and portrait (the actual photoshop files behind the links have my own artwork removed):