Motion Video Adaptive Quantization in the Transform Domain

We have developed a minimax adaptive quantization algorithm that operates in the Discrete Cosine Transform domain. The algorithm is designed to optimize image quality by adapting a quantizer scaling factor to the local characteristics of the video pictures while preserving a constraint on the average output bit rate. The algorithm is well suited for real-time encoder implementations of current video compression standards, such as MPEG and H.261. © 1991 IEEE