Abstract: A method and system for defining a sequence of files by placing a numerical value in the header of the file, without using an index. Newly-positioned files are positioned between existing files by the determination and assignment of a numerical value between the numerical values of the previous and succeeding existing files.

Abstract: When receiving input scan lines from a conventional scanner, a system of the present invention simultaneously provides a sequence of pixels for display and a second sequence of pixels for storage, for example on a hard disk. A pixel for display has an intensity resolution greater than a pixel of the input scan line. The intensities of scan line pixels in a 16 by 16 matrix are accumulated for incrementally revising the intensity of the pixel to display. An incremental intensity is identified by a table indexing technique. The second sequence is the result of performing a data compression method on two sets of transitions. Each set is derived from an input scan line by noting the run length between changes in intensity. Intensities in one embodiment have single bit resolution. A subset of transitions is identified by a table indexing technique. Disk writes are delayed until a buffer has exceeded a limit value.

Abstract: Disclosed is a method and system for data compression. In a preferred embodiment, an input stream of data bytes are compressed into an encoded stream using an LZ77-based scheme. The preferred method searches for a matching sequence of already processed data bytes that is identical to a current sequence of bytes. Sequences of literals (bytes not forming part of a matching sequence) or match codes (encoded matching sequences) are identified by count values indicating the number of literals or match codes in the sequence. Preferably, the encoded stream is transmitted from a first computer to a second computer, where the encoded stream is decompressed. The method uses matching circular history buffers for compression and decompression, the history buffers being synchronized using a coherency byte included with each frame of encoded data transmitted. If an encoded frame is not received by the decompression device, the decompression device transmits a flush request to the compression device.