Need of Image Encryption
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.