Introduction - If you have any usage issues, please Google them yourself
Using wavelet transform image compression: wavelet transform for image compression, is the use of high-frequency part of the wavelet decomposition of the image, leaving only the low-frequency part, can be seen from the figure, the first is to extract the compressed image wavelet decomposition first layer low-frequency information, when the compression is better, the second compression is to extract the low frequency part of the second layer, which is far better than the first compression pressure