Title:
ORTHOGONAL CONVERSION ENCODER
Document Type and Number:
Japanese Patent JP2833290
Kind Code:
B2
Abstract:
PURPOSE: To reduce the block noise for such a block by controlling the step width quantizing the orthogonal conversion coefficient of block of visually noticeable picture such as an edge part.
CONSTITUTION: The orthogonal conversion encoder is provided with an orthogonal converter 11 orthogonally converting the inputted block, an edge detecting device 12 detecting whether or not an edge is in the inputted block, and an encoder 13 reducing the compression ratio of the block with edge when performing the bit compression so as to obtain the prescribed amount of data while taking the output of the orthogonal converter 11 and the output of the edge detecting device 12 as input. When the edge detecting device 12 detects an edge is in the block, the quantization coefficient of the output of a quantization selection circuit 22 is made small. For example, 1/4 quantization is replaced by 1/2 quantization. Thus, the orthogonal conversion coefficient with less error can be obtained, reducing the block noise.
More Like This:
Inventors:
MATSUDA TOYOHIKO
NISHINO SHOICHI
AWAMOTO SHIGERU
NISHINO SHOICHI
AWAMOTO SHIGERU
Application Number:
JP25503091A
Publication Date:
December 09, 1998
Filing Date:
October 02, 1991
Export Citation:
Assignee:
MATSUSHITA DENKI SANGYO KK
International Classes:
H03M7/30; G06T9/00; H04N1/41; H04N19/126; H04N19/136; H04N19/14; H04N19/176; H04N19/189; H04N19/196; H04N19/60; H04N19/85; H04N19/86; (IPC1-7): H04N7/30; G06T9/00; H03M7/30; H04N1/41
Domestic Patent References:
| JP2105791A | ||||
| JP326081A | ||||
| JP2222386A |
Attorney, Agent or Firm:
Tomoyuki Takimoto (1 person outside)