Research On Lossless Compression Technology Based On DSP

With the rapid development of many electronic communications equipment,aerospace technology and storage testing technology,explosive growth of massive data has been brought about.Therefore,reducing the consumption of data information storage resources and improving the transmission efficiency of data information between transmission devices is an important field and a popular trend in the current research of science and technology.Based on this background,data compression technology has emerged.The test data involved in this paper have the characteristics of good local correlation,fast change,accounting for relatively small,and most of the data are relatively stable.By analyzing the data characteristics applicable to the relevant lossless compression algorithm and the difficulty of hardware implementation,the LZW compression algorithm suitable for the above test data to achieve the corresponding lossless compression function.The program of LZW compression and decompression algorithm is written in MATLAB software and the principle and execution process of the algorithm are analyzed.The search method of Hash table is selected to complete the rapid search of the dictionary and the corresponding solutions to the hash function and address conflicts are designed;using C language LZW compression and decompression algorithm program based on Hash table search is designed,and the key parameters such as compression ratio and compression time of the compression algorithm are analyzed.Using the measured data of the above characteristics to study the length of the hash table in the compression algorithm and the impact of the space utilization on the compression performance when the dictionary is updated,the performance of the compression algorithm is tested using a number of measured data.When the length of the hash table is 4K When left and right,both the better compression effect can be obtained and the hardware resources can be fully saved;when the dictionary space utilization reaches 80% to 90%,the dictionary update can achieve a smaller compression time.Improve the way of updating the dictionary: When the dictionaryis updated,the content of the dictionary that is frequently used is retained,and only the content that uses the frequency is updated;the compression performance of the improved update method is analyzed,and the compression ratio of the same data can be compressed.Decrease from 5% to 10%.Design a DSP-based hardware compression system and perform a modular design based on the corresponding functions.Through the DSP hardware development platform to achieve the compression function,the compressed system to process the above characteristics of the measured data when the average compression rate analysis: When the CPU master clock is 200 MHz,the average compression rate can reach 10MBytes/s.