1992-08-28
1997-03-11
Coles, Sr., Edward L.
395115, G06F 1500
Patent
active
056110243
ABSTRACT:
A method and apparatus for storing compressed bit map images in a laser printer. Bit map images representing a page of data are divided into bands and compressed into the printer memory. Then, when needed by the interpreter/rasterizer, they are decompressed into another portion of that memory, or when desired to print those bands they are directly transmitted to a decompression engine. The bands of bit map image are compressed using a Lempel-Ziv algorithm that contains improvements allowing compression towards the end of the band and improves the compression speed at the beginning of the band by initializing a hash table. Further, the interpreter/rasterizer switches between compression routines depending on the available memory and the desired speed of compression. The compression routine requests supplemental destination buffers when it needs additional memory in which to compress data. Finally, the compression continues to add margin white space during the compression of the uncompressed bit images so that margin what space need not be stored in the uncompressed bit image.
REFERENCES:
patent: 4631597 (1986-12-01), Ogawa
patent: 4791680 (1988-12-01), Yokoe et al.
patent: 4881180 (1989-11-01), Nishiyama
patent: 5047955 (1991-09-01), Shope et al.
patent: 5109476 (1992-04-01), Thompson
patent: 5295238 (1994-03-01), Dickson
Welch, T.A., "A Technique for High-Performance Data Compression." iEEE Computer, (Jun. 1984), pp. 8-19.
Williams, R.N., "An Extremely Fast ZIV-Lempel Data Compression Algorithm." DCC '91--Data Compression Conference, (Storer & Reif, eds., 1991), pp. 362-371.
Knuth, D.E., "Sorting & Searching", The Art of Computer Programming, vol. 3, Addison-Wesley, 1973, pp. 506-542.
Adams Greg
Braaten Jeffrey M.
Campbell Scott O.
Coles Sr. Edward L.
Compaq Computer Corporation
Popovici Dov
LandOfFree
Data compression of bit map images does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Data compression of bit map images, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Data compression of bit map images will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-450724