Image coding-from waveforms in animation

The main coding techniques for efficient electronic representation of grayscale images are reviewed. The emphasis is on understanding some of the reasons behind the development of different coding structures. It is shown that various (conscious or unconscious) models of the scene, the image, and the visual system have been and are still being used as the driving source for the construction of coding algorithms. Methods covered in this include delta modulation, predictive coding, transform coding, vector quantization, hybrid coding, subband coding, and semantic image coding. The last two schemes are covered in greater detail. Subband coding forms a bridge between traditional (waveform) concepts and perceptual coding. Semantic coding is an example of a class of new coding techniques based on (3-D) object modeling