用小波变换和LGB编码的方法压缩黑白图片。对图像进行小波变换后，仅对细节系数进行压缩，而且不同小波变换层的细节系数的压缩程度不一样。-Using wavelet transform and coding method LGB compress black and white picture. After the wavelet transform of the image, only the details of the coefficient is compressed, and different layers of the details of the wavelet transform coefficients hold different compression levels.