Adaptive transform coding of still images

Details Adaptive transform coding of still images Adaptive transform coding of still images

1989-07-19

1992-06-09

Coles, Sr., Edward L.

Facsimile and static presentation processing

Facsimile

Recording apparatus

358426, 358432, 358433, 382 56, H04N 141

Patent

active

051212161

ABSTRACT:
In accordance with our adaptive transform coding algorithm for a still image, the image is divided into small blocks of pixels and each block of pixels is transformed using an orthogonal transform such as a discrete cosine transform. The resulting transform coefficients are compressed and coded to form a bit stream for transmission to a remote receiver. The compression parameters for each block of pixels are chosen based on a busyness measure for the block such as the magnitude of the (K+1).sup.th most significant transform coefficient. This enables busy blocks for which the human visual system is not sensitive to degradation to be transmitted at low bit rates while enabling other blocks for which the human visual system is sensitive to degradation to be transmitted at higher bit rates. Thus, the algorithm is able to achieve a tradeoff between image quality and bit rate.

REFERENCES:
patent: 4581638 (1986-04-01), Chiariglione et al.
patent: 4698689 (1987-10-01), Tzou
patent: 4710822 (1987-12-01), Matsunawa
patent: 4754492 (1988-06-01), Malvar
patent: 4774574 (1988-09-01), Daly et al.
patent: 4805030 (1989-02-01), Tanaka
patent: 4853778 (1989-08-01), Tanaka
patent: 4922273 (1990-05-01), Yonekawa et al.
patent: 4979038 (1990-12-01), Guichard et al.
"Scene Adaptive Coder," W. H. Chen et al., IEEE Trans. Commun., vol. COM-32, pp. 225-232, Mar. 1984.
"Improvements of Transform Coding Algorithm for Motion-Compensated Interframe Prediction Errors-DCT/SQ Coding," M. Kaneko et al., IEEE J. Selected Areas in Commun., vol. SAC-5, pp. 1068-1078, Aug. 1987.

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