Format compliant RoI encryption of JPEG XR bitstreams based on tiling

Tiling is used to facilitate format compliant region of interest encryption of JPEG XR codestreams. The proposed technique can be used with any desired cryptographic cipher and avoids decoding problems by modifying the tile index of the image in order to prevent a decoder to process the encrypted parts. Experimental examples are given and the impact of tiling on compression performance is assessed.