(12) United States Patent ao) Patent No.: us 6,888,970 B2
Sandford (45) Date of Patent: May 3,2005
(54) WAVELET TRANSFORMATION ENGINE
(75) Inventor: Mark J. Sandford, Lake Forrest, CA (US)
(73) Assignee: LightSurf Technologies, Inc., Santa Cruz, CA (US)
( * ) Notice: Subject to any disclaimer, the term ol this patent is extended or adjusted under 35 U.S.C. 154(b) by 715 days.
(21) Appl. No.: 10/010,567
(22) Filed: Nov. 8, 2001
(65) Prior Publication Data
US 2002/0143834 Al Oct. 3, 2002
Related U.S. Application Data
(60) Provisional application No. 60/262,568, filed on Jan. 18, 2001.
(51) Int. CI.7 G06K 9/54; G06K 9/60
(52) U.S. CI 382/302; 382/240
(58) Field of Search 382/240, 248,
382/302, 303, 304, 263, 264; 708/300, 308, 313, 400, 406
(56) References Cited
U.S. PATENT DOCUMENTS
An ASIC-implemented wavelet transformation engine (circuit) providing a wavelet filter is described. The wavelet filter itself provides up to a 9-stage FIR (finite impulse response) filter with symmetrical coefficients. The architecture of the filter includes data inputs, a bank of shift registers (register bank), coefficient registers, a multiplier/ accumulator, a sub-sampling component, and output (results) registers. The filter provides a wavelet-based compression solution that may be implemented in less-costly, page-based memory architecture (e.g., SDRAM), and does so in a manner that overcomes the inherent speed disadvantage encountered due to the horizontal-optimized access strategy employed by page-based memory architectures.
70 Claims, 4 Drawing Sheets