Patent ID: 7630568
Filing Date: 2009-12-08
Classification: H04N

Abstract:
1. A system for generating reduced resolution versions of an input signal from a hierarchical transform (HT) representation of the signal, comprising steps for: decoding an HT coded signal up to a highest current hierarchical transform level not exceeding a desired signal resolution to produce a plurality of decoded blocks of transform coefficients; if the desired signal resolution directly corresponds to the current hierarchical transform resolution level, scaling grouped DC coefficients of the decoded blocks of transform coefficients, and lowpass filtering the resulting signal in the signal domain to generate an output signal having the desired signal resolution; and if the desired signal resolution does not directly correspond to the current hierarchical transform resolution level, scaling the decoded blocks of transform coefficients, lowpass filtering the scaled decoded blocks of transform coefficients in the transform domain, applying an inverse transform to the filtered scaled decoded blocks of transform coefficients, and downsampling the resulting signal to generate an output signal having the desired signal resolution.