Software Modeling And Driving Development Based On JPEG Hardware Codec

With the development of sensor technology and image processing techniques,personal mobile terminal has been one of the main equipments to collect,store,process and transmit the high-precision digital images.As it is difficult to store large number of high-precision image data and meet the requirement of real-time transmission,hardware image codec is widely used in the personal mobile terminal.In consideration of the hardware's design cost and system power dissipation.It is popularly welcome by manufactures to integrate hardware codec the on-chip SOC system in the form of IP.At present,IP system is usually designed in the way of hardware and software cooperation.Compared with the previous hardware priority design scheme,it adds a system software modeling step before the hardware module design.System software modeling is the core link of hardware and software co-design method for hardware IP system,through the software modeling of the IP system,the feasibility of the algorithm can be analyzed in the early stage of the system design,and the performance evaluation and optimization of the system architecture can be improved,it also greatly shorten the hardware design cycle and improve the hardware structure.Therefore,the establishment of hardware IP system software model has the development value and practical significance.This paper introduces the basic steps of JPEG static image codec protocol firstly,then,starting from the application scenarios of mobile phone users,this paper analyzes the functional requirements of image codec IP,and designs an IP system architecture which meets the requirements of codec.Finally,the encoding and decoding system is modeled by C language according to the system architecture.The model contains software and hardware modules.In the hardware part of the software modeling,software simulates hardware ping-pong operation to read the data stream.Design a fast algorithm for integer color system conversion and establish a software model of hardware color conversion module.The quantization table in line with the human visual system is applied to the quantization model of image compression coding.Compared with a variety of classic DCT fast algorithm,considering the occupation of the multiplier and the accuracy of the algorithm,the Loeffler algorithm is selected to replace the original DCT algorithm to model the hardware DCT module.By analyzing the Huffman encoding and decoding method of the hardware,establish the Huffman coding table storage format and look-up table model.In the software part,establish the encapsulation and de encapsulation modules of BMP and JPG format.In order to improve the compression ratio of image encoding,we propose a hardware encoding with the minimum visible visual difference model assumption of quantization table,experiments show that the new quantization table is better than the traditional quantization table and can be used for JPEG hardware codec IP,but this kind of method has brought the quantization table too large problem which can't be solved at present.In the later stage of hardware IP completion,the Zedboard FPGA development board of Xillinx is used to integrate the JPEG codec IP into the FPGA system in the Vivado development platform.The software part is combined with the read-write register module to generate the IP driver to realize the hardware and Software co-coding and decoding of IP.