Image Compression: A Survey <s> S-TREE AND SHADING APPROACH <s> This paper presents a moment preserving and visual information dominance technique to achieve the low-bit rate block truncation coding (BTC). Compared with other existing strategies as transform coding and vector quantization, conventional BTC compression has the advantage of simple and fast computation. Nevertheless the compression ratio is limited by its low efficiency. Our proposed technique accomplishes the goal of simple computation with variable bit rate selection by the moment preservation and information extraction algorithm. The proposed technique has the advantage of simple operations and it does not require complicated mathematical computations. Thus, the overall computation does not increase the burden compared with ordinary BTC. The simulations are carried with natural images to evaluate the performance. The generated decoded images have moderate quality with a bit rate of 0.5-1.0 bit/pixel. <s> BIB001 </s> Image Compression: A Survey <s> S-TREE AND SHADING APPROACH <s> Distasi et al. (see ibid., vol.45, p.1095-1100, 1997), presented a storage-saving image compression method called the B-tree triangular coding (BTTC) method. Based on the modified S-tree data structure and the Gouraud shading method, this paper presents an improved image compression method railed the S-tree compression (STC) method. Experimental results illustrate that the bit rates and the image quality of the proposed STC method are quite competitive with the BTTC method, Due to the simple geometrical decomposition in the STC method, the ratio of the execution time or the proposed method over the BTTC method is less than 1/2. <s> BIB002
Novel method is presented for compression of gray image Rate of bits and the quality of image shows that STC method is reliable then BTCC method. Execution cycle of proposed method is min than half than BTCC. In each block by considering noise and increasing the execution time image's quality is also preserved in a satisfactory ways of proposed shade tree method can get improvement at very high rate BIB002 BIB001 .