60results about How to "Encoding implementation" patented technology

The invention discloses an absolute position coding and decoding method for an optical grating of an absolute position displacement sensor. The absolute position coding and decoding method comprises the following steps that the optical grating with absolute position coding is divided into N code channels, wherein the first code channel is an absolute code channel, and the other n-1 code channels are equidistant increment code channels; the absolute code channel is composed of a parity bit cross-region identification code area, a gray code area, an interval code area (with or without) and an over-interval code area (with or without); the equidistant increment code channels comprise low-order equidistant increment code channels and high-order equidistant increment code channels which areprovided with evenly spaced scribing lines; the number of the scribing lines of the low-order equidistant incremental code channels is equal to the number of gray codes; the number of the scribing lines of the high-order equidistant incremental code channels can be arranged as required; the corresponding code is "1" when light passes through or reflects from an optical grating absolute code channel coding area to a photoelectric element, and the corresponding code is "0" is when light does not pass through or reflect to the photoelectric element; and during decoding, position data read by thecode channels are integrated through FPGA chips. The absolute position coding and decoding method can ensure that the absolute position coding within any coding length range is unique.

By combining a plurality of encoding methods actively, an encoding efficiency is enhanced. The first encoder (5) encodes a result of determination whether a prediction error is zero or not. The second encoder (6) encodes the prediction error unless the prediction error is zero. The third encoder (8) encodes the prediction error regardless of whether the prediction error is zero or not. The mode determinator (2) determines the encoding mode, and the encoding controller (11) selectively operates the first encoder (5), the second encoder (6), and the third encoder (8) according to the encoding mode determined.

A method for realizing Huffman decoding includes receiving data stream being Huffman-coded, intercepting different cipher of data stream and using it as word to be decoded, comparing word to be decoded separately with address indexing table used to indicate code word position in Huffman code table to obtain corresponding Huffman code table address then obtaining data symbol before Huffman table by seeking Huffman table according to Huffman code table address and outputting obtained data symbol out. The device used for realizing said method is also disclosed.