Question is simple yet confusing, why there is the need for image encryption. How text encryption is different from image encryption if using same technique like AES, DES, Chaotic algorithm. If the only difference is at implementation it's more of engineering task than science. Can same encryption technique applied to both text and image, then why image encryption a separate part.
There is no need for those image encryption algorithms.
- You can encrypt an image file, like any other sequence of bytes using standard encryption.
- If you really want to encrypt the pixels themselves (not recommended), you can use standard length preserving encryption, such as a four round feistel network.
I've seen some image encryption papers, but they were badly written by people with little understanding of cryptography and not published in cryptography journals/conferences.