Title:
TRANSMISSION RATE CONVERTER FOR MOVING IMAGE
Document Type and Number:
Japanese Patent JP3963296
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To provide a transmission rate converter that can convert a transmission rate into a desired transmission rate efficiently at a high-speed without the need for complicated processings, such as re-encoding and without causing visible deterioration in moving image data after the conversion.
SOLUTION: A requantization section 4 subjects a conversion coding coefficient to requantization with updated quantization parameters. A DCT coefficient subtract section 7 subtracts a conversion coding coefficient COEF6 after requantization from a conversion coding coefficient COEF2 to obtain a conversion coding coefficient error DCOEF1 attended with requantization. An inverse DCT conversion section 9 generates difference pixel data DPIX1 from the conversion coding coefficient error DCOEF1. The difference pixel data DPIX1 are given to an error-compensation means consisting of a difference frame adder section 10, difference image memory section 11, a difference pixel distribution measurement section 12, a DCT conversion section 13 and a DCT coefficient adder section 3 to compensate a conversion coding coefficient error attended with the requantization.
Inventors:
Masaru Kanno
Yasuyuki Nakajima
Hiromasa Yanagihara
Yoneyama Akio
Yasuyuki Nakajima
Hiromasa Yanagihara
Yoneyama Akio
Application Number:
JP37065399A
Publication Date:
August 22, 2007
Filing Date:
December 27, 1999
Export Citation:
Assignee:
Kddi research institute
International Classes:
H04N1/41; H04N7/24; H04N19/00; H04N19/12; H04N19/132; H04N19/136; H04N19/154; H04N19/18; H04N19/196; H04N19/40; H04N19/48; H04N19/50; H04N19/503; H04N19/51; H04N19/513; H04N19/593; H04N19/61; H04N19/625; H04N19/85; H04N19/91; H04N19/94; (IPC1-7): H04N7/24; H04N1/41
Domestic Patent References:
| JP11252546A | ||||
| JP8237663A | ||||
| JP9512395A | ||||
| JP3285484A |
Other References:
Pedro A. A. Assuncao and Mohammed Ghanbari,A Frequency-Domain Video Transcoder for Dynamic Bit-Rate Reduction of MPEG-2 Bit Streams,IEEE Transactions on circuits and systems for video technology,1998年12月,Vol. 8, No. 8,p.953-967
Attorney, Agent or Firm:
Kaori Tanaka
Michito Hiraki
Michito Hiraki