在计算机图像处理系统中，图像的最大特点和难点就是海量数据的表示与传输，因此如何有效快速地存储和传输这些图像数据成为当今信息社会的紧迫要求[1]。在当代通信中，数字图像传输已经成为重要内容，在工作中除要求设备可靠、图像保真度高以外，实时性是重要技术指标之一，与文字信息不同的是，图像信息占据大量的存储空间所用传输信道也比较宽。-Crisis is to our life what illness is to our body. Just as fatal disease can destroy our body and sometimes even put an end to our lives, so does smashing crisis knock us down so hopelessly that we might never have chance of standing up again. However, most crises that frequent us in life are not such category. They, like occasional ailments which sometimes can bolster our body s immune system, are mostly minor and surmountable and therefore making us hardy enough to survive whatever adversities in our later life.