Wavelet compression

Wavelet compression is a form of data compression especially for image compression (sometimes also video compression). The goal is to write image data as compressed as possible into a file. A certain loss of quality is accepted (lossy compression).

Method

First a wavelet transform is applied. This produces as many coefficients as there are pixels in the image. These coefficients can be compressed more easily because the information is statistically concentrated in just a few coefficients. This principle is called transform coding. After that, the coefficients are quantized and the quantized values are entropy encoded and/or run length encoded.

Examples for wavelet compression:

• JPEG2000
• SPIHT