The emphasis of this thesis is studying the methods of bit allocations of digital image compression based on wavelet transform and managing to minimizing the overall distortion . we know from the rate - distortion theory that the aim is gainable 由率失真理论我们知道，对于给定的码率，可以找到一种比特分配算法对小波变换后的各个子带进行比特分配，使重建图像的失真达到最小。
