三种宽色域视频信号兼容传输处理方案

Three Signal Processing Schemes for Transmission of Wide Color Gamut Video Signal

宽色域数字电视标准ITU-R BT.1361限定伽马校正前的基色信号幅度范围为-0.25^+1.33,笔者用遍历法计算了其相应的最宽可感知色域,导出了对应的新三基色,证明其色域覆盖率达60.65%。为使该色域信号能在现行ITU-RBT.709常规色域视频系统兼容传输,依据IEC61966—2—4许用量化级范围,提出了一种非线性量化方案。基于新三基色并采用相应的编码方式,不扩展许用量化级,也可实现该宽色域信号的兼容传输,若再将坐标系旋转78°,则可进一步改善相应编码信号的传输性能。CIEDE2000色差评价值表明,以上三种可选方案均可有效实现宽色域视频兼容传输。

Wide color gamut DTV standard ITU-R BT.1361 define the amplitude range of pre-gamma correction color signal is -0.25 - ＋1.33. In this paper, the widest perceivable color gamut and the corresponding three primary colors under this range are calculated, the coverage ration of this color gamut is 60.65%, and a kind of nonlinear quantization method according to the available quantization level range in IEC 61966-2-4 to convey this gamut compatibly in current ITU-R BT.709 conventional color gamut video system is developed. It points out that the compatible convey of signals in this wide color gamut can also be realized by using new set of encoding scheme based on the new primary colors without the extension of quantization levels, if rotating the coordinate system by 78°, the transmission performance of encoded signals can be inproved. CIEDE2000 color difference results show that the above three schemes can effectively realize the compatible convey of wide color gamut video signals.