Accession Number : ADA138876

Title :   Adaptive Hybrid Picture Coding.

Descriptive Note : Interim rept. 1 Apr-30 Nov 83,


Personal Author(s) : Jones,R A ; Cook,M K

PDF Url : ADA138876

Report Date : 30 Nov 1983

Pagination or Media Count : 198

Abstract : The transmission of digital imagery has become a necessity in recent times. Systems such as communications and weather satellites, facsimile, remote control, and machine intelligence can and do make use of data compression techniques to reduce bandwidth and power consumption. Research on these techniques has led to one form of image data compression which achieves good image quality for intraframe coding at low data rates. This technique is known as Adaptive Stochastic Picture Coding (ASPC) which consists of a one-dimensional unitary transform for column-wise decorrelation used in conjunction with Adaptive Differential Predictive Coding Modulation (ADPCM) for the row-wise decorrelation, followed by quantization to give the desired data compression. This system requires use of quantization techniques which limit system performance. Optimization of adaptive scalar quantizers and use of vector quantizers aid in the adaptation of the system to variations in the image statistics. This report represents a study of such quantizers in the ASPC system. By examining these quantization methods, it will be shown that it is vital that the proper quantizer be incorporated into the system to achieve a particular data rate at desired distortion levels. (Author)

Descriptors :   *Mathematical models, *Image processing, *Data compression, *Coding, *Pictures, *Data transmission systems, Quantization, Low rate, Data rate, Signal processing, Adaptive systems, Hybrid systems, Computerized simulation, Electrical engineering, Histograms, Subroutines

Subject Categories : Numerical Mathematics
      Computer Programming and Software

Distribution Statement : APPROVED FOR PUBLIC RELEASE