Title:
【発明の名称】画像データを圧縮および伸張する方法および装置
Document Type and Number:
Japanese Patent JP2000516048
Kind Code:
A
Abstract:
Image data such as text or half-tone images is compressed and decompressed. A compressor has three phases: a bit-run length phase that counts the length of each run of consecutive identical pixels; a pairs-repetition phase that compresses repeated pairs of pixel run values to one copy of the repeated pair and a repeat count; and an optional dictionary-based micro-table encoder. The micro-table, which may be used in any application calling for a least recently used (LRU) mechanism, has multiple qualification layers, with elements within a qualification layer being promoted to the next higher qualification layer upon the occurrence of a table hit for that element, and being demoted to the next lower qualification layer by being bumped by elements promoted up from below. The result is a table that is weighted both by frequency and recency of hits.
Inventors:
Fraser allen el
Bradburn Brent M
Bradburn Brent M
Application Number:
JP51118997A
Publication Date:
November 28, 2000
Filing Date:
August 05, 1996
Export Citation:
Assignee:
HEWLETT-PACKARD COMPANY
International Classes:
G06T9/00; H03M7/30; H03M7/40; H03M7/46; H04N1/41; H04N1/413; (IPC1-7): H03M7/40; H04N1/41; H04N1/413
Attorney, Agent or Firm:
Tsukio Okada