Partial Fractal Model for Hybird Image Coding

Abstract

The fractal image compression technique models a natural image using a contractive mapping called fractal mapping in the image space. In this chapter, we first introduce the concept of fractal mapping and some useful definitions. In Section 5.2, we demonstrate that the fractal image coding algorithm is compatible with other image coding methods. A new mapping in the image space, called partial fractal mapping is proposed in Section 5.3. A general framework of fractal-based hybrid image coding encoding/decoding systems is presented in Section 5.4. Section 5.5 proposes a new hybrid image coding scheme, which non-fractal coded regions are used to help the encoding of fractal coded regions. Experiments in Section 5.6 show that the proposed system performs better than the quadtree-based fractal image coding algorithm and the JPEG image compression standard at high compression ratios larger than 30.