This document reviews various techniques for encrypting images using chaotic maps. It begins with an abstract summarizing that image encryption has become important with digital communication growth. Chaotic encryption is an alternative due to chaotic maps' sensitivity to initial conditions and unpredictability. The document then reviews concepts of image encryption, cryptography, and chaotic systems. It surveys several existing image encryption schemes based on chaotic maps and their approaches, such as using the Henon map or selective encryption of image components. The typical architecture of chaos-based image cryptosystems is also described.