Identification of JPEG 2000 images in encrypted domain for digital cinema

A bit-stream-level method for identifying encrypted JPEG 2000 images without having to decrypt them is described. It is well known that editing the scenes of the movie is often necessary. In the editing process, image identification plays an important role in finding a frame that should be re-encoded. Thus, identification of encrypted images is very useful in digital cinema because all frames in digital cinema are encoded and encrypted. The proposed method directly uses encrypted JPEG 2000 images so that decryption-free identification without JPEG 2000 decoding is possible. The proposed method is both accurate and fast. In principle, identification based on the proposed method does not produce false negative matches regardless of the compression ratio. Moreover, since there is no need to decode and decrypt the images, the average processing time for identification is very short and independent of the encoded image size.