High Capacity Steganography Scheme for JPEG2000 using SPIHT Algorithm

Redundancy available in digital media makes it possible to hide messages within various digital carriers like image, audio. Steganography is useful for secret communication. If images are taken as carrier for steganography any information either image, audio can be embedded into that image. But as images are frequently compressed before transmission or storage, information hiding in a compressed data format should be a better choice. JPEG2000 is latest image coding standard which uses embedded block coding truncation (EBCOT). It exhibits excellent compression performance with high complexity. The need to reduce this complexity but maintain similar performance as EBCOT has inspired significant amount of research in image coding community. Within development of image compression techniques based on wavelet transform Embedded Zero tree Wavelet (EZW) & Set Partitioning In Hierarchical Tree (SPIHT) played important role. SPIHT algorithm achieves fewer features with low complexity than EBCOT. Hiding capacity is very important for covert communication.For compressed images,it is necessary to enlarge the hiding capacity because the available redundancy is very limited.