Title:
HIGH EFFICIENCY CODING DEVICE
Document Type and Number:
Japanese Patent JP3025983
Kind Code:
B2
Abstract:
PURPOSE: To provide the high efficiency coding device in which deterioration in picture quality is not remarkable even when information quantity is compressed.
CONSTITUTION: A low frequency component discrimination value arithmetic operation 7 outputs a minimum value and a maximum value of absolute sum of differences of adjacent picture elements in each sub-block as to a low frequency component of a parameter deciding a quantization level of each block with respect to an image signal subject to sub band division and block processing in horizontal or vertical direction and a high frequency component discrimination value arithmetic operation 8 outputs a maximum value of absolute sum of differences of adjacent picture elements in each sub-block as to a high frequency component. A discriminator 9 discriminates whether or not a block is a block whose picture quality deterioration is remarkable based on the output of the low frequency component discrimination value arithmetic operation 7 and the high frequency component discrimination value arithmetic operation 8 to decide the quantization level of the entire blocks. An adaptive quantizer 4 applies adaptive quantization to the output of an orthogonal transformation circuit 3 according to the quantization level.
Inventors:
Yoshinori Asamura
Application Number:
JP3941292A
Publication Date:
March 27, 2000
Filing Date:
February 26, 1992
Export Citation:
Assignee:
Mitsubishi Electric Corporation
International Classes:
H03M7/30; G06T9/00; H04N1/41; H04N19/126; H04N19/134; H04N19/136; H04N19/14; H04N19/176; H04N19/196; H04N19/423; H04N19/46; H04N19/59; H04N19/60; H04N19/625; H04N19/635; H04N19/70; H04N19/80; H04N19/85; H04N19/91; (IPC1-7): H04N7/30; H03M7/30; H04N1/41
Domestic Patent References:
| JP2105792A | ||||
| JP3291058A |
Attorney, Agent or Firm:
Norio Kawano