This is where navigation should be.

DEMO_IMAGECOMPRESSION - Image compression using N-term approximation

Description

This demo shows how to perform a simple imagecompression using either a Wilson basis or a Wavelet. The compression step is done by retaining only 5% of the coefficients.

demo_imagecompression_1.png

Wilson and WMDCT basis

This right figure shows the image compressed using a dwilt basis with 8 channels. This corresponds quite closely to JPEG compression, except that the borders between neigbouring blocs are smoother, since the dwilt uses a windowing function.

The left figure shows the same, now using a MDCT basis. The MDCT produces more visible artifacts, as the slowest changing frequency in each block has a half-wave modulation. This is visible on otherwise smooth backgrounds.

demo_imagecompression_2.png

Wavelet

The Wavelet used is the DB6 with \(J=5\) levels. On the right figure the standard layout has been used, on the left the tensor layout was used.