The Influence of Impairments from Digital Compression of Video Signal on Perceived Picture Quality

Publisher Summary Generally, the performance of a video compression system can be evaluated objectively or subjectively. The objective methods are based on computable distortion measure such as mean squared error or signal to noise ratio (SNR). Objective measurements have limited effectiveness in predicting the quality of compressed images as seen by the observers. On the other hand, subjective assessment is geared directly toward properties of the human visual system. Subjective assessments are controlled psycho-physical experiments that are designed to find out how the observers would judge picture quality. It is the reason why subjective assessment is the most effective method for determining the influence of video compression method on picture quality. Picture impairments in digital video systems are different from those that occur in analogue systems and depend on the methods of coding and redundancy reduction employed. With the increasing applications of moving picture experts group (MPEG) coding, the assessment of MPEG coding impairments becomes very important. The aim of this chapter is to present results of picture quality assessment in relation to impairments from MPEG-1 coding for workstation and personal computer applications where pictures are displayed within a window on a monitor.