1
Joan L Mitchell, William B Pennebaker, Jorma J Rissanen: Dynamic model selection during data compression. International Business Machines Corporation, Thomas P Dowd, September 3, 1991: US05045852 (132 worldwide citation)

A system and method for maximizing data compression by optimizing model selection during coding of an input stream of data symbols, wherein at least two models are run and compared, and the model with the best coding performance for a given-size segment or block of compressed data is selected such t ...


2
Cesar A Gonzales, Joan L Mitchell, William B Pennebaker: Adaptive graylevel image compression system. International Business Machines Corporation, Marc A Block, February 16, 1988: US04725885 (92 worldwide citation)

Apparatus and method for modelling differential pulse code modulation (DPCM) input data for entropy coding. In particular, the sign and magnitude of one piece of DPCM data after another are modelled to provide a magnitude state input and a sign state input to provide context for DPCM magnitude input ...


3
Joan L Mitchell, William B Pennebaker: Arithmetic coding data compression/de-compression by selectively employed, diverse arithmetic coding encoders and decoders. International Business Machines Corporation, Marc A Block, Thomas P Dowd, January 2, 1990: US04891643 (91 worldwide citation)

A data compression/de-compression system includes a first arithmetic coding encoder, characterized by a first set of encoding conventions, which encoder generates a code stream that points to an interval along a number line in response to decision event inputs. The code stream can be adjusted to poi ...


4
Glen G Langdon Jr, Joan L Mitchell, William B Pennebaker, Jorma J Rissanen: Arithmetic coding encoder and decoder system. International Business Machines Corporation, Thomas P Dowd, February 27, 1990: US04905297 (84 worldwide citation)

Apparatus and method for compressing and de-compressing binary decision data by arithmetic coding and decoding wherein the estimated probability Qe of the less probable of the two decision events, or outcomes, adapts as decisions are successively encoded. To facilitate coding computations, an augend ...


5
Dimitris Anastassiou, William B Pennebaker: Correction of shading effects in video images. International Business Machines Corporation, Thomas P Dowd, September 22, 1987: US04695884 (80 worldwide citation)

Video images are corrected for shading effects by generating a histogram of picture element (pel) gray scale intensity values and calculating the median and the black and white extremes thereof. A range of permitted background gray scale values is empirically selected such as by calculating the dist ...


6
William B Pennebaker: Thresholding technique for graphics images using histogram analysis. International Business Machines Corporation, Thomas P Dowd, Terry J Ilardi, April 7, 1987: US04656665 (77 worldwide citation)

A system is described for thresholding graphics images to reduce the information content for transmission and reproduction and which uses a particular image data thresholding technique that may be used to obtain display images with a number of intensity levels. Firstly, an histogram of the image to ...


7
William B Pennebaker: Adaptive quantization within the JPEG sequential mode. International Business Machines Corporation, Sterne Kessler Goldstein & Fox, October 20, 1992: US05157488 (60 worldwide citation)

A system and method for masking adaptive quantization during compressed image data transmission by defining a scaling factor for the quantization tables of the multiple image components, wherein the scaling factor signals changes in quantization for successive blocks of the image data. The scaling f ...


8
Karen L Anderson, William B Pennebaker, Keith S Pennington: Method for enlarging an image stored in run representation form. International Business Machines Corporation, Thomas P Dowd, December 5, 1989: US04885786 (58 worldwide citation)

The method according to the present invention enlarges a binary digital image by a method comprising the steps of: storing the rows of the image as a plurality of run end representations, in which a row is represented as a sequence of values giving the white and black run ends; enlarging each row of ...


9
Frederick Hochberg, William B Pennebaker, Keith S Pennington: Micromist jet printer. International Business Machines Corporation, Philip Young, April 19, 1977: US04019188 (55 worldwide citation)

A micromist printing arrangement wherein a micromist of ink particles, provided by an ultrasonic nebulizer, is forced through a small nozzle to form an aerosol jet. The micromist ink particles are entrained in the jet and focused to print a narrow width region which is substantially smaller in size ...


10
William B Pennebaker, Joan L Mitchell: Probability adaptation for arithmetic coders. International Business Machines Corporation, Marc A Block, Thomas P Dowd, June 19, 1990: US04935882 (53 worldwide citation)

Apparatus and method for adapting the estimated probability of either the less likely or more likely outcome (event) of a binary decision in a sequence of binary decisions involves the up-dating of the estimated probability in response to the renormalization of an augend A. The augend A changes valu ...