A kind of nonlinear quantization method to extend the color gamut of DTV system

ITU-R BT.1361 and IEC 61966-2-4(xvYCC) are two standards for video systems with extended-gamut YCC color space. IEC 61966-2-4 put forward that the available quantization levels can be extended to [1, 254] in 8-bit quantization. This paper calculated the value range of luma and chroma signals corresponding to this available quantization range with the colorbar signal which has been widely used in TV system, and put forward a nonlinear (piecewise linear) quantization method for chroma signals to solve the problem that the range of extended chroma signals is beyond the conveyable range. Experimental data with two standards (ITU-R BT.1361 and IEC 61966-2-4) were given out respectively, the results show that this scheme can effectively extend the color gamut with some color difference (DeltaE₀₀) between transmission and reception side.