改进的混合压缩算法在 GPS数据压缩中的应用

摘要

In the paper we introduce a hybrid compression algorithm , which is the combination of Huffman algorithm and RLE algorithm , for compressing the GPS data .This algorithm acquires statistical characteristics of GPS data according to the NMEA 0183 protocol , mixes Huffman algorithm and RLE algorithm to compress GPS data , to improve the coding efficiency and to restrain data expansion .Huffman algorithm has high compression rate on duplicated single-byte data while RLE algorithm has high compression rate on duplicated code segment.The flag bit is added in the process of encoding for the classification processing on GPS data in order to effectively identify the outputs of two kinds of algorithm when decoding and to ensure the complete decoding of compressed data .This improved hybrid compression algorithm is applied to local storage and 3G remote transmission of vehicle terminal GPS data , results show that the algorithm has clear improvement in compression performance of GPS data .%介绍一种Huffman算法与RLE（ Run-Length Encoding ）算法相结合的混合压缩算法对车载监控系统GPS数据进行压缩处理。该算法依据NMEA0183协议获取GPS数据的统计特性，混合对重复的单字节数据的压缩率高的Huffman算法以及对重复码段压缩率高的RLE算法，对GPS数据进行压缩，提高数据的编码效率，抑制数据膨胀。在编码过程中添加标志位，对GPS数据进行分类处理，便于解码时有效识别两种算法的输出，保证对压缩的数据进行完整解码。将改进的混合压缩算法应用于车载终端GPS数据的本地存储与3G远程传输，结果表明该算法对GPS数据的压缩性能具有明显提高。