Perception-based image transcoding for universal multimedia access

In this paper, we propose a novel scheme for generating transcoded (e.g. scaled and cropped) image to fit the size of the respective client display when an image is transmitted to a variety of client devices with different display sizes. The scheme has two key components; i) perceptual hint for each image block, and ii) an image transcoding algorithm. For a given semantically important block in an image, the perceptual hint provides the information on the minimum allowable spatial resolution reduction. The image transcoding algorithm that is basically a content adaptation process selects the best image representation to meet the client capabilities while delivering the largest content value. The content value is defined as a quantitative measure of the information on importance and spatial resolution for the transcoded version of an image. Experimental results demonstrate a feasibility of the proposed scheme with a variety of client devices having different display sizes.