Method and apparatus for implementing wavelet filters in a digital system
AssigneeMotorola, Inc.
InventorsYolanda Prieto, Jose I. Suarez, Yolanda M. Pirez
Life of this patent
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Abstract
A digital data system (100) provides 1-D, 2-D and 3-D capability and multi-band channel capability. Improved filter banks are created by generating a filter bank having an analysis portion and synthesis portion and obtaining wavelet coefficients (302) for each portion. The wavelet coefficients are expressed in a format capable of canonical signed digit (CSD) representation, such as integers (302). The canonical signed digit (CSD) representation is controlled by a value, N, selected to control resolution of the CSD coding. Optimized CSD-coded wavelet coefficients are used as filters for data signals (318).
Claims11
A method of generating a multiplierless filter implementation for filtering a data signal in a digital signal processing system, comprising the steps of:
- receiving an input data signal;
- generating a series of wavelet filter coefficients;
- representing the wavelet filter coefficients using a canonical signal digit (CSD) optimization technique to obtain a first optimal set of CSD represented wavelet filter coefficients;
- converting the wavelet coefficients into an optimal format capable of a CSD representation to yield a second optimal set of CSD represented wavelet coefficients;
- adaptively selecting from the set of the second optimal CSD representation for obtaining a subset of CSD represented wavelet coefficients;
- generating a multiplierless filter with the converted wavelet coefficients based on an adaptively selected number of terms to create an adaptively selected subset of the CSD represented wavelet coefficients;
- and
- applying the adaptively selected subset of the CSD represented wavelet coefficients to the input data signal.
A method of filtering an input data signal in a digital processing system comprising the steps of:
- receiving an input signal;
- generating a series of wavelet coefficients for an analysis filter bank;
- representing the wavelet filter coefficients using a canonical signal digit (CSD) optimization technique to obtain an original optimal set of CSD represented wavelet coefficients;
- adaptively selecting a subset of terms from the original optimal set of CSD representation based on the significance of a subband to produce a sub-dependent CSD representation;
- and
- applying a subband-dependent CSD representation of an encoding filter bank to an input data signal.
Dependencies are inferred from the claim text.