Patent ID: 6249546
Filing Date: 2001-06-19
Classification: H04N

Abstract:
An adaptive guantization method in a coding process for coding data values corresponding to each picture element (pel) of a portion of a video frame, the method comprising the steps of:selecting, for each portion of a video frame, a quantizer set R.sub.x of quantizer values from a group of guantizer sets R.sub.0 -R.sub.n, where each quantizer set differs from each other quantizer set in the group;modifying each data value by a selected offset value;correlating each modified data value with a quantizer value from the selected quantizer set R.sub.x to provide a quantized set of values corresponding to the pel data values;varying the offset value within a predetermined range;determining the distortion and bit rate characteristics provided for each offset value in the predetermined range by each quantizer set in the group of quantizer sets R.sub.0 -R.sub.n ; andselecting the quantizer set and an associated offset value based on the distortion and bit rate characteristics provided by the combination of each quantizer set in the group and each offset value.