1.0 - 8.00 - IDWT2D - Teradata Vantage

Teradata® Vantage Machine Learning Engine Analytic Function Reference

Product
Teradata Vantage
Release Number
1.0
8.00
Release Date
May 2019
Content Type
Programming Reference
Publication ID
B700-4003-098K
Language
English (United States)

The IDWT2D function is the inverse of DWT2D; that is, IDWT2D applies inverse wavelet transforms on multiple sequences simultaneously. IDWT2D takes as input the output table and meta table output by DWT2D and outputs the sequences as 2-dimensional matrixes. (Because the IDWT2D output is comparable to the DWT2D input, the inverse transformation is also called the reconstruction.)



This is a typical IDWT2D use case:

  1. Apply DWT2D to 2-dimensional sequences to create the coefficients of the matrixes and corresponding metadata.
  2. Filter the coefficients by methods appropriate for the objects (for example, minimum threshold or top n coefficients), compressing the original matrixes.
  3. Apply IDWT to the filtered coefficients to reconstruct the sequences.
  4. Compare the reconstructed matrixes to their original counterparts.