Kien T Nguyen

US Patent:

6470052, Oct 22, 2002

Filed:

Jun 29, 1998

Appl. No.:

09/106580

Inventors:

Uoc H. Nguyen - Long Beach CA
Kien T. Nguyen - Torrance CA
Abraham E. Claproth - Culver City CA
Arnold Hackett - Pasadena CA

Assignee:

Xerox Corporation - Stamford CT

International Classification:

H04N 712

US Classification:

37524022

Abstract:

Using hierarchical vector quantization (HVQ) to accomplish rotation in addition to compression and decompression. During the compression step the image is divided into segments and each segment is reduced to a codeword. These codewords are transposed so that the segments will be in rotated order when printed. Then the codewords are decompressed to form segments in which the pixels are in rotated order.

US Patent:

6529553, Mar 4, 2003

Filed:

Apr 15, 2002

Appl. No.:

10/123786

Inventors:

Uoc H. Nguyen - Long Beach CA
Kien T. Nguyen - Torrance CA
Abraham E. Claproth - Culver City CA
Weili Lin - Irvine CA

Assignee:

Xerox Corporation - Stamford CT

International Classification:

H04N 712

US Classification:

37524022

Abstract:

In a system where two types of data are to be compressed using hierarchical vector quantization (HVQ), it would be typical for there to be two compression tables, one optimized for each type of data. A boundary between the two types may occur within a block to be compressed. In this case, a third table, optimized for a block having both types of data, is used.

US Patent:

62052527, Mar 20, 2001

Filed:

Jun 29, 1998

Appl. No.:

9/106581

Inventors:

Uoc H. Nguyen - Long Beach CA
Kien T. Nguyen - Torrance CA
Abraham E. Claproth - Culver City CA
Sang-chul Kang - Irvine CA
Chia-hao Lee - Hacienda Heights CA

Assignee:

Xerox Corporation - Stamford CT

International Classification:

G06K 936
G06K 946

US Classification:

382234

Abstract:

A compression process of dividing each word to be compressed into least and most significant bits, and applying a different compression ratio to each. If the compression processes are lossy, both parts of the output can also be losslessly compressed before being output. Hierarchical vector quantization can be issued for either lossy compressor.

US Patent:

60786965, Jun 20, 2000

Filed:

Jun 29, 1998

Appl. No.:

9/106734

Inventors:

Uoc H. Nguyen - Long Beach CA
Kien T. Nguyen - Torrance CA
Abraham E. Claproth - Culver City CA
Thanh D. Truong - Walnut CA

Assignee:

Xerox Corporation - Stamford CT

International Classification:

G06K 936
G06K 938
G06K 946

US Classification:

382253

Abstract:

Printing hints can be efficiently compressed in a system using hierarchical compression (HVQ) by first using HVQ to generate compressed codewords, and then adding the printing hint to the codewords to generate an intermediate form of codeword, before sending this intermediate form to a pattern matching lossless compressor for final compression. Even though the same printing hint may be applied to a number of codewords, the overall compression will be affected very little by the addition of the printing hints since the hints are identical over a large number of codewords in series.