Title:
画像情報変換装置およびビットストリーム変換機ならびに画像情報変換送信方法
Document Type and Number:
Japanese Patent JP4275358
Kind Code:
B2
Abstract:
In a bitstream transcoder, the computational cost and the memory area are suppressed so that stream transcoding is performed with a reduced number of times of computing and a reduced memory area. The transcoder includes a VLD portion 11 for performing VLD on a bitstream encoded in MPEG-2 to output quantized DCT coefficients; an IQ portion 12 for receiving the coefficients, and outputting inverse-quantized DCT coefficients; a coefficient table 132 for storing a transformation matrix obtained by multiplying transformation matrices for operating band-limiting filter, IDCT, down-sampling and DCT, respectively, together in advance; a DCT scaling portion 13 for performing down-sampling on the DCT coefficients by use of the transformation matrix; a Q portion 15 for outputting quantized DCT coefficients down-sampled horizontally and vertically; and a VLC portion 16 for encoding the quantized DCT coefficients in MPEG-4 to output a bitstream.
Inventors:
Hiroshi Nakamura
Naoki Yamamoto
Takuya Imade
Hiroyasu Otsubo
Naoki Yamamoto
Takuya Imade
Hiroyasu Otsubo
Application Number:
JP2002170476A
Publication Date:
June 10, 2009
Filing Date:
June 11, 2002
Export Citation:
Assignee:
株式会社日立製作所
International Classes:
H04N19/50; H03M7/30; H03M7/40; H04N19/40; H04N19/423; H04N19/426; H04N19/46; H04N19/51; H04N19/59; H04N19/60; H04N19/625; H04N19/70; H04N19/80; H04N19/91
Domestic Patent References:
| JP10023261A | ||||
| JP2002152755A | ||||
| JP8181988A | ||||
| JP8051625A | ||||
| JP2001112002A |
Other References:
Changhoon Yim and Michael A. Isnardi,An Efficient Method for DCT-Domain Image Resizing with Mixed Field/Frame-Mode Macroblocks,IEEE Transactions on circuits and systems for video technology,1999年 8月,vol. 9, no. 5,p. 696-700
Attorney, Agent or Firm:
Patent Business Corporation Daiichi International Patent Office