Bandwidth efficiency of an image compression method for information hiding

In order to improve the compression rate of vector quantization (VQ) during compression, a re-encoding scheme, called spiral scan re-encoding (SSR), was designed to compact the indices in VQ. Based on the SSR scheme, we propose a novel lossless hiding scheme, called IHSSR. When the scheme is used, information is hidden in the compression code for increasing the bandwidth efficiency of the compressed code. The IHSSR system was developed to test the performance of the IHSSR scheme. According to the experimental results, the IHSSR system can efficiently hide secret information in the compression code of indices without modifying its content. The decoding process can obtain the hidden secret information and the indices. Only a small number of extra bits are needed to record the corresponding information.