Patent ID: 6961472
Filing Date: 2005-11-01
Classification: H04N

Abstract:
1. A method of inverse quantizing quantized signal samples of an image during image decompression comprising: applying a process to transform the quantized signal samples from a first domain to a second domain, the transform process comprises an inverse discrete wavelet transform (IDWT) to decompose signal samples into two or more subbands; and during the transform process, filtering quantized signal samples by applying scaled filter coefficients, the signals samples first being filtered along the image in a first direction and then along the image in a second direction, so that at the completion of the transform process of the image, at least a selected portion of the transformed signal samples are inverse quantized, wherein the inverse quantization is integrated into the IDWT process, wherein scaling in a first mutually orthogonal direction comprises: applying a first scale factor to each filter coefficient in the low pass filtering operation to subbands LL applying a second scale factor to each filter coefficient in the high pass filtering operation to subband LH applying a third scale factor to each filter coefficient in the high pass filtering operation to subband HH HL, HH, LH, and LL in the k