Patent ID: 6421144
Filing Date: 2002-07-16
Classification: H04N

Abstract:
A picture encoding apparatus for encoding inputted picture data to generate a plurality of hierarchy data being a plurality of resolutions which are recursively different, comprising:means for determining quantization characteristics of a low hierarchy data being a resolution higher than that of upper hierarchy data being a low resolution, based on an activity of said upper hierarchy data, in which the quantization characteristics of the low hierarchy data are different from the quantization characteristics of the upper hierarchy data; and means for quantizing each of the upper and low hierarchy data in accordance with said determined quantization characteristics of each hierarchy, wherein the determining means determines a quantization step width for said low hierarchy data in accordance with the following equation: p1=GÃ—p0 wherein p1 represents the quantization step width of said low hierarchy data, p0 represents the quantization step width of the upper hierarchy data, and G represents gain, in which for a situation wherein the activity is relatively large and a first pattern of quantized values exists the gain (G) has a value of 2 when N2Ã—0, the gain (G) has a value of 1.5 when N1Ã—1, and the gain (G) has a value of 1.0 when N1>TH0 and N2 >TH1 in which TH0 and TH1 are threshold values, N1 represents a frequency of the first pattern, and N2 represents a frequency of a second pattern of quantized values.