Method and apparatus for encoding and decoding key data

摘要

An apparatus and a method for encoding key data are provided, which can increase the efficiency of encoding key data by identifying a linear key data region in input differential data. The key data encoder includes a linear key encoder, a floating-point number converter, a quantizer, an entropy encoder, and a key header encoder. When key data are input into the key data encoder, the linear key encoder searches for a region where key data linearly increases, i.e., a linear key data region, in the input key data and outputs the beginning and ending key data of the linear key data region to the floating-point number converter. The input key data except for the linear key data region are input into the quantizer. The key data input into the quantizer are quantized with predetermined quantization bits and are output to the entropy encoder. The entropy encoder encodes the quantized key data input from the quantizer and outputs the result as a bitstream. The floating-point number converter converts the beginning and ending key data of the linear key data region which are represented by binary numbers into the decimal system and outputs the results of the conversion to the key header encoder so that they can be included in the bitstream. The key data encoder may further include a quantization error minimizer.