Midstream content access based on color visual pattern coding

It has been argued that future image coding techniques should allow for 'midstream access', i.e. allow image query, retrieval, and modification to proceed on the compressed representation. In a recent work, we introduced the color visual pattern image coding (CVPIC) technique for color image compression. An image is divided into blocks and each block coded locally by mapping it to one of a predefined, universal set of visually significant image patterns consisting of representations for both edge and uniform regions. The pattern and color information is then stored, following a color quantization algorithm and an entropy encoding stage. Compression ratios between 40:1 and 60:1 were achieved while maintaining high image quality on a variety of natural color images. It was also shown that CVPIC could achieve comparable performance to state-of-the- art techniques such as JPEG.