SAVING DATA AFTER COMPRESSION


After compressing the signal , you can save   the following quantities  generated during the compression operation.

  1. The vector of signal samples.
  2. The vector of wavelet coefficients.
  3. The vector of wavelet coefficients, which are compressed but not encoded.
  4. The vector of wavelet coefficients, compressed and encoded.
  5. The new .wav file of reconstructed signal.

Of these, the fourth point  needs some explanation. Recollect that our objective was to have a  compressed representation of the original .wav file  . This new file, therefore, should contain all the relevant information needed to  reconstruct the signal from the wavelet coefficients. It contains such information as sampling frequency and bits per second of the original signal, the type of wavelet used for compression, the level of decomposition , length of wavelet coefficient vector et al.

When you attempt to save the file, after giving a valid name, the file is not saved with the name given by you. Instead , a prefix of   'comp' is used to identify such compressed and encoded file.

       eg: suppose you choose to name a file as   'myfile' . Then the file will be stored the specified directory as  'compmyfile.mat' .