The following constraints are recommended ratios for formatting iOS wallpapers and images that are pushed from AirWatch:
iPhone – Do not exceed a ratio of 2.88 width over height
iPad – Do not exceed a ratio of 4.39 width over height
AirWatch Logo Ratios
iPhone – 1.35 width over height
iPad – 1.26 width over height
Additional things to note:
If the image exceeds a height of 111 points (iPhone) or 175 points (iPad), then the image will be scaled down while maintaining the aspect ratio. If the image’s height is smaller than 111 points (iPhone), then no scaling will be done. Keep in mind “points" are an iOS concept and are not the same as pixels. The conversion from points to pixel will depend specifically on your device. For example, on an old iPhone 4, 1 point = 1 pixel; on retina iPads, 1 point = 2 pixels; on iPhone 6 Plus, 1 point = 3 pixels.