I have a question about comparing UIImages in Objective-C when one image has already been through a save and load process using the NSSearchPathForDirectoriesInDomains metho
You can compare the image name or the image URL if it was downloaded from Internet, it will also be faster than comparing the images.
Also, the problem is that by using the == operator you are comparing the memory addresses of the images 0x95614c0 and 0xde748f0. That's why is not equal. You are comparing if they are the same object, not if the images are equal.
To compare images use: As mentioned on Fls'Zen answer.
if ([UIImagePNGRepresentation(blackImage) isEqualToData:UIImagePNGRepresentation(greenImage)])