Steven L Pratt

US Patent:

6771275, Aug 3, 2004

Filed:

Jun 7, 2000

Appl. No.:

09/589935

Inventors:

Craig C. Cook - Wayland MA
Steven J. Pratt - Acton MA
Fred W. Andree - Brookline MA

Assignee:

Oak Technology, Inc. - Sunnyvale CA

International Classification:

G09G 502

US Classification:

345604, 345601

Abstract:

A signal conversion system parses a multi-dimensional input signal into most-significant and least-significant portions. The most-significant portions are used as an index to a look-up-table. Stored in each entry of the look-up-table is a base value and multi-dimensional differential values. The system generates an output representation of the signal by combining the corresponding base value with interpolated differences determined by interpolation performed using the differential values and the least-significant portions. Interpolation error is decreased by storing intermediate differential values. Output processing is used for linearization.

US Patent:

8599439, Dec 3, 2013

Filed:

Sep 19, 2008

Appl. No.:

12/234500

Inventors:

Shenbo Yu - Andover MA, US
Fred W. Andree - Brookline MA, US
Steven J. Pratt - Acton MA, US

Assignee:

CSR Imaging US, LP - Burlington MA

International Classification:

G06F 3/12
H04N 1/409

US Classification:

358 326, 358 115, 358 304, 358 303, 358 305, 358534, 358536, 358 31, 358 33

Abstract:

An apparatus and a method are described for processing and reproducing a document including both text and half-tone images without generating undesirable image artifacts. A band-pass FIR filter with a predetermined frequency response is used to transform pixels in an input image to sharpen text edge and smooth pre-half-toned areas, and perform error diffusion and cluster dot screening methods on the transformed pixels. The FIR filter has unity gain at DC to preserve image brightness. An integrated error diffused cluster-dot screening approach is used to suppress moiré and other image artifacts, while providing a robust, crisp output.

US Patent:

20040046761, Mar 11, 2004

Filed:

Jun 28, 2002

Appl. No.:

10/185791

Inventors:

Timothy Hellman - Concord MA, US
Neil Epstein - Sudbury MA, US
Steven Pratt - Acton MA, US
Fred Andree - Brookline MA, US
Karl Marks - Somerville MA, US
Joerg Landmann - Dortmund, DE
James Brissette - W. Boylston MA, US

Assignee:

Oak Technology, Ink - Sunnyvale CA

International Classification:

G06F015/16
G06F013/14

US Classification:

345/502000, 345/520000

Abstract:

A system-on-a-chip controller having a first processor and a second processor. The first processor provides control processing and image processing. The second processor provides image processing. The processors receive data from an external source through a data bus. Also, the controller can include a third controller to provide I/O functionality to an external device. The second processor processes the stored data in either a row or column configuration. A fixed-length instruction word can be decoded into two instructions, an operation instruction and an I/O instruction, and can be used to process the data. The I/O instruction can be disposed in an unused bit field of the operation instruction.