Consideration on and compensation for violations of the constant luminance principle for EDTV

Evaluation tests of the HDTV system show that a reduction of the chrominance signal bandwidth is possible if gamma correction is performed at the receiver. The number of bits required in the chrominance signals is discussed. For an enhanced television system, the authors propose the use of precompensation methods at the transmitter to improve the picture-quality of highly saturated color pictures. These methods have been adopted in the EDTV (enhanced-definition TV) television system in Japan. The authors also discuss the flarelike reproduction of the black level caused by beam cutoff in the cathode-ray tube (CRT) display and band limitation of the chrominance signals.<>