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Algazi, V. R.

Publications and source records attributed to Algazi, V. R..

32 records · Page 2
All sourcesNASA NTRSDOE OSTI
NASA NTRS1973

Source encoding of images for efficient transmission

A set of recursive rules which generate unitary transforms with a fast algorithm are presented. For each rule, simple relations give the number of elementary operations required by the fast algorithm. The common Fourier, Walsh-Hadamard, Slant, and Haar transforms are expressed with these rules. The framework developed allows the introduction of generalized transforms which include all common transforms in a large class of identical computation transforms. A systematic and unified view is provided for unitary transforms which have appeared in the literature and for a number of new transforms of potential interest. Generalization to complex and multidimensional unitary transforms is considered.

Algazi, V. R.↗
NASA NTRS1973

Digital enhancement of multispectral MSS data for maximum image visibility

A systematic approach to the enhancement of images has been developed. This approach exploits two principal features involved in the observation of images: the properties of human vision and the statistics of the images being observed. The rationale of the enhancement procedure is as follows: in the observation of some features of interest in an image, the range of objective luminance-chrominance values being displayed is generally limited and does not use the whole perceptual range of vision of the observer. The purpose of the enhancement technique is to expand and distort in a systematic way the grey scale values of each of the multispectral bands making up a color composite, to enhance the average visibility of the features being observed.

Algazi, V. R.↗
NASA NTRS1972

An integrated study of earth resources in the state of California based on ERTS-1 and supporting aircraft data

There are no author-identified significant results in this report. Results of an integrated study of earth resources in the state of California using ERTS-1 and supporting aircraft data are presented. Areas of investigation cover (1) regional agricultural surveys; (2) solving water resource management problems; (3) resource management in Northern California using ERTS-1 data; (4) analysis of river meanders; (5) assessment and monitoring change in west side of the San Joaquin Valley and central coastal zone of state; (6) assessment and monitoring of changes in Southern California environment; (7) digital handling and processing of ERTS-1 data; (8) use of ERTS-1 data in educational and applied research programs of the Agricultural Extension Service; and (9) identification, classification, and mapping of salt affected soils.

Colwell, R. N.↗
NASA NTRS1972

Adaptive line by line encoder for image transmission.

A simple adaptive algorithm is applied to the line by line encoding of images. Among its desirable properties the algorithm includes a control of encoding errors independently of the image statistics. This block transform encoder, because of its adaptive nature gives rise to nonstationary errors and end of block effects. Two methods are proposed to reduce these effects and thus improve the subjective quality of reconstructed images. The performance of the algorithm is image dependent and several illustrative examples are given.

Algazi, V. R.↗
NASA NTRS1964

Statistical communication theory

Generalization of superposition principle of statistical communication theory & investigation of class of nonlinear systems

STATISTICAL COMMUNICATION THEORY↗