Digital images play an important role in our daily lives and are used in many applications. Hence, there is a need to protect them from unauthorized access and modification. During the past years, several image encryption algorithms have been proposed. Image encryption techniques jumble the pixels of the plain image and reduce the association among the pixels, such that any adversary cannot modify the encrypted image. Chaotic encryption method seems to be much better day by day. The chaos based cryptographic algorithms are one of the emerging and efficient ways to develop secure image encryption techniques. Several schemes have been proposed and analyzed in the past decade based on chaotic maps. Chaotic maps require initial conditions to start iterations and usually initial conditions are derived using the external secret key by providing different weightage to all its bits. A comparative analysis and behavior of the chaotic image encryption schemes proposed in the past decade is presented in this paper such that further enhances in the field of image security can be explored.