高清晰度电视信号用外插内插预测编码方法

An Extrapo Iative—Interpolative Prediction Coding Method for HDTV Signals

本文介绍了一种高清晰度电视(HDTV)信号的数字传输用高效编码方法。由于HDTV信号的带宽宽,所以存在两个主要问题:一是HDTV信号的随机噪声比传统电视信号的大,因而导致编码的效率下降;二是需要很高的取样频率。这样,就限制了编码算法的硬件实现。因此,本文提出两种技术来解决这些问题:第一是时空自适应滤波器,用它可降低随机噪声并改善编码效率;第二是具有自适应内场/帧间预测的外插和内插编码算法,这种算法消除了因高的取样频率引起的问题并保证了高效编码性能。

This paper describes a high efficieney coding method for digital transmission of HDTV (high definition television) signals. Because of the wide bandwidth of HDTV signals, there are two major problems. One is that HDTV signals have more random noise than conventional TV signals, which causes coding efficiency degradation. The other is that very high sampling frequencies are required. This restricts the hardware implementation of the coding algorithm. Therefore, two techniques are introduced to solve these problems. The first is a spatio-temporal adaptive filter that can reduce random noise and improve coding efficiency. The second is an extrapolative and interpolative coding algorithm with adaptive intrafield/interframe prediction. This algorithm eliminates the problem caused by the high sampling frequencies and provides efficient coding performance. A computer simulation is carried out to estimate the coding perform ance. Based on the simulation results, experimental coder hardware is imple- mented for 1125 line/60 Hz HDTV signals in order to evaluate real-time coding performance. The experimental relults showed that this codeng method can provide good picture quality at around 90 or 135 Mb/s, and that HDTV digital transmission is very promising at the broad-band ISDN H_4 rate.