Back  Contents   Next

STEPS INVOLVED IN DECOMPOSITION

1. Pass each row through the low and high half bandpass decomposition filters and place the downsampled outputs (downsampling by a factor of 2) as shown to obtain two subbands.

2. Pass each column through the half band pass filters and place the downsampled outputs as shown to obtain four subbands.

LL- whole image is shrunk to ¼ of its size, its details are removed and the  remaining approximations are stored in LL.

HH- details are stored and approximations are removed.

RECONSTRUCTION

The reconstruction process is the exact reverse of the decomposition process. First the columns have to be processed using low and high half band pass reconstruction filters and then the rows.

Back  Contents   Next                                                                                                                                   ZAP Works