Title:
METHOD, APPARATUS AND SYSTEM FOR DETERMINING LUMA VALUE
Document Type and Number:
Japanese Patent JP2017118492
Kind Code:
A
Abstract:
PROBLEM TO BE SOLVED: To provide a method of determining a Luma value from 4:4:4 RGB video data for encoding chroma downsampled 4:2:0 YCbCr video data into a bitstream.SOLUTION: A location, in a color space defined by linear luminance and non-linear 4:2:0 chroma values, is determined from RGB video data 112 in color space conversion 114 of a system 100 and a region that contains the determined location is determined. The region is one region of a plurality of regions located in the color space and having a plurality of associated coefficients. One or more of the coefficients associated with the determined region are selected. The selected coefficients are used to map the linear luminance and non-linear 4:2:0 chroma values to a Luma value that compensates for luminance introduced by chroma downsampling of the non-linear 4:2:0 chroma values. The Luma value is then determined according to a function of the selected coefficients and the determined location.SELECTED DRAWING: Figure 1
Inventors:
CHRISTOPHER JAMES ROSEWARNE
VOLODYMYR KOLESNIKOV
VOLODYMYR KOLESNIKOV
Application Number:
JP2016243681A
Publication Date:
June 29, 2017
Filing Date:
December 15, 2016
Export Citation:
Assignee:
CANON KK
International Classes:
H04N11/20; H04N9/67; H04N19/85
Domestic Patent References:
| JP2004514354A | 2004-05-13 | |||
| JP2008172599A | 2008-07-24 |
Foreign References:
| WO2015124754A1 | 2015-08-27 | |||
| WO2015007505A1 | 2015-01-22 | |||
| WO2015095361A1 | 2015-06-25 | |||
| US20100309336A1 | 2010-12-09 | |||
| US20150245041A1 | 2015-08-27 |
Attorney, Agent or Firm:
Yasunori Otsuka
Yasuhiro Otsuka
Shiro Takayanagi
Shuji Kimura
Osamu Shimoyama
Nagakawa Yukimitsu
Yasuhiro Otsuka
Shiro Takayanagi
Shuji Kimura
Osamu Shimoyama
Nagakawa Yukimitsu