A New Image Compression Method Based on Primal Sketch Model

In this paper, we introduce the primal sketch model which might lead to a new image compression method. The primal sketch model integrates two modeling schemes for two type components in natural images: the sketchable and the non-sketchable parts. The sketchable part explains the structural components of the image by using a hidden layer of image primitives. The non-sketchable part denotes the remaining textural components without distinguishable elements by Markov random field models for texture images. The primitives in the image representation are not independent but organized as a sketch graph. The whole image can be coded by a sketch graph with a primitive dictionary and texture descriptors. Such a lossy coding scheme could achieve the compression ratio of 20 to 40 for natural images. With the similar visual effect, the coding length of JFEG2000 is about 1.5 to 3 times higher. This promising compression method could be applied to some situations such as wireless transmission where the bandwidth is critical and low quality images are still acceptable.