Patent ID: 6535558
Filing Date: 2003-03-18
Classification: H04N

Abstract:
A picture encoder for encoding picture signals of a lower hierarchy representing pre-set picture signals and picture signals of an upper hierarchy similarly representing pre-set picture signals, comprising:a first encoding unit for encoding the picture signals of the lower hierarchy using first reference pictures for outputting first pre-set encoded data; a second encoding unit for encoding the picture signals of the upper hierarchy using third reference pictures for outputting second pre-set encoded data; a first decoding unit for decoding said first encoded data for generating the first reference pictures; a second decoding unit for decoding said second encoded data for generating second reference pictures; differentiating means for determining a frame to frame difference value for pixels of the first reference pictures; comparing means for comparing the difference value and a predetermined threshold value on a pixel by pixel basis; and generating means for generating the third reference pictures by adaptively switching on a pixel by pixel basis between the first reference pictures and the second reference pictures based on a result of the comparing means, wherein for a given pixel position of the third reference picture, a value of a corresponding pixel in the first reference picture is used when the difference value is larger than the predetermined threshold value, and a value of a corresponding pixel in the second reference picture is used when the difference value is less than the predetermined threshold value.