Framework of A Hybrid Image Compression Algorithm for View-dependent Visualization

This paper presents a framework of a hybrid method designed to decompress image blocks of tile-pyramid used in virtual environment especially for flight simulation. It combines two compression algorithms, namely DCT-based compression and WT-based one. Two estimator functions are proposed to choose between these two algorithms. To balance decompression performance against image quality, a selective mechanism for decompression method is introduced that depends on LOD level, image quality, bit rates and tile size. Our method is CPU-based and achieves real-time rendering performance with high image quality superior to pure DCT-based method and WT-based method.