Tamper detection and retrieval technique based on JPEG2000 with LL subband

The LL subband from the discrete wavelet transform (DWT) in JPEG2000 is actually a smaller sized compressed image of the original in spatial domain. In this paper, we propose a tamper detecting and retrieval scheme to extract and hide special characteristic values of the entire LL subband in the level one subbands, 1LH and 1HL. The hidden data will be used later with a digital signature and a public key to prove the authenticity of the image. Tampered areas could be accurately detected and recovered with quality that is visually acceptable. Our scheme can be used to authenticate sensitive images like the medical images, to prove rightful ownerships, and to recover images before the originals are available.