Since the digital representation of raw video signals requires a high capacity, low complexity video coding algorithms must be defined to efficiently compress video sequences for storage and transmission purposes. The proper selection of a video coding algorithm in multimedia applications is an important factor that normally depends on the bandwidth availability and the minimum quality required. For instance, a surveillance application may only require limited quality, raising alarms on identification of a human body shape, and a user of a video telephone may be content with only sufficient video quality that enables him to recognise the facial features of. | Compressed Video Communications Abdul Sadka Copyright 2002 John Wiley Sons Ltd ISBNs 0-470-84312-8 Hardback 0-470-84671-2 Electronic 2 Overview of Digital Video Compression Algorithms Introduction Since the digital representation of raw video signals requires a high capacity low complexity video coding algorithms must be defined to efficiently compress video sequences for storage and transmission purposes. The proper selection of a video coding algorithm in multimedia applications is an important factor that normally depends on the bandwidth availability and the minimum quality required. For instance a surveillance application may only require limited quality raising alarms on identification of a human body shape and a user of a video telephone may be content with only sufficient video quality that enables him to recognise the facial features of his counterpart speaker. However a viewer of an entertainment video might require a DVD-like service quality to be satisfied with the service. Therefore the required quality is an application-dependent factor that leads to a range of options in choosing the appropriate video compression scheme. Moreover the bit and frame rates at which the selected video coder must be adaptively chosen in accordance with the available bandwidth of the communication medium. On the other hand recent advances in technology have resulted in a high increase of the power of digital signal processors and a significant reduction in the cost of semiconductor devices. These developments have enabled the implementation of time-critical complex signal processing algorithms. In the area of audiovisual communications such algorithms have been employed to compress video signals at high coding efficiency and maximum perceptual quality. In this chapter an overview of the most popular video coding techniques is presented and some major details of contemporary video coding standards are explained. Emphasis is placed on the study and performance analysis .
