图象质量客观测试的研究

Objective Measurement of Picture Quality in Multimedia Communications

研究了多种图象质量客观测试的方法， 其中关于块损伤提出了两种测量方法： （１） 采用水平平方波作测试图象， 计算重建图象的信噪比； （２） 计算图象中边缘信息的统计分布Ｑ， 比较原始与重建图象的Ｑ值即可得到关于图象块效应大小的描述．提出了测量运动补偿效果及帧速的方法， 并且发现传统的模拟客观测试方法对某些压缩编码失真仍然有效， 而且具有简单成熟的优点，

Several objective methods have been investigated. Two methods that give a distortion measure for blocking artifacts in images are presented. The first one uses an artificial test signal as the inputa horizontal square signal. The output PSNR is an indication of blocking artifacts. The second one is based on edge extraction. A statistic is calculated to produce a scalar quantity Q , and then a comparison of Q between the input and the output is used to detect blocking artifacts. Methods for evaluation of performance of motion compensation and for measurement of frame rate are also discussed. Furthermore, the “old” analog measurement methods have been found to be useful in detecting some sorts of compression artifacts. Simple and reliable, the analog measurement should be a complement to modern objective testing system.