Title:
VIDEO SIGNAL PROCESSING DEVICE
Document Type and Number:
Japanese Patent JP3132168
Kind Code:
B2
Abstract:
PURPOSE: To improve the degradation of the picture quality by reducing the quantization error brought about in processes of quantization and inverse quantization used for video signal compression.
CONSTITUTION: At the time of recording, 8×8 unit blocks subjected to DCT operation are quantized by first and second quantizers 55 and 57 and are compressed with a variable length code. At the time of reproducing, the signal decoded by a variable length decoder 62 is subjected to inverse operation of quantization by an inverse quantizer 63. Simultaneously, a quantization discriminator 64 determines whether correction is necessary or not in accordance with a quantization condition (class information, color information, quantization step Brn, and area information) supplied from the inverse quantizer 63 and outputs a control signal to a corrector 65. The corrector 65 performs correction by addition/subtraction of a certain value to/from the inversely quantized value based on this control signal. The output signal of the corrector 65 is subjected to IDCT operation and is outputted to an output terminal 68.
Inventors:
Eiji Yamauchi
Tatsuro Shigesato
Masaru Nakahama
Tatsuro Shigesato
Masaru Nakahama
Application Number:
JP20484792A
Publication Date:
February 05, 2001
Filing Date:
July 31, 1992
Export Citation:
Assignee:
Matsushita Electric Industrial Co., Ltd
International Classes:
H04N5/92; H04N19/00; H04N19/126; H04N19/134; H04N19/136; H04N19/149; H04N19/176; H04N19/186; H04N19/189; H04N19/196; H04N19/625; H04N19/65; H04N19/85; H04N19/88; H04N19/89; H04N19/91; (IPC1-7): H04N5/92; H04N7/24
Domestic Patent References:
| JP1162085A | ||||
| JP4123587A | ||||
| JP556275A |
Attorney, Agent or Firm:
Fumio Iwahashi (2 others)