Basic HTML version of Foils prepared 22 February 97
Foil 4 Wavelets
From 3D Geographic Information System Rome Lab Quarterly Review for CIV -- October 1 96. byRemek Trzaska, Pawel Roman, Chris Walczak *
Wavelet decomposition extracts the most important information (low frequencies) and less meaningful details (higher frequencies)
to compress the wavelet coefficients we use Embedded Zerotree Algorithm:
the coefficients describing low frequencies are placed in the front of the stream, higher frequencies are placed further;
the coefficients can be roughly approximated using only the beginning of the stream, further part of the stream provides additional refinement information.