Research Of JPEG-LS Lossless Compression Algorithm Based On FPGA

JPEG-LS is an algorithm for the static continuous tone image lossless or near lossless compression in the new ISO/ITU standard.Based on the theoretical research of JPEG-LS lossless compression algorithm,this thesis presents the design of Cameralink image acquisition and processing system based on FPGA.Due to the high reliability and fast transmission speed of Cameralink transmission image data,the Cameralink interface protocol is used to transmit image data,which can solve the speed matching problem between image data output and acquisition.The thesis implements the design of CameraLink image acquisition and processing system based on FPGA,which mainly combines image excitation source unit with Cameralink image acquisition and processing unit.The implementation of JPEG-LS lossless compression algorithm by FPGA is an important part of the system image processing.This thesis,based on FPGA,focuses on the realization of JPEG-LS lossless compression algorithm.It mainly using the modular design of VHDL language to achieve context modeling,predictive coding and Golomb coding,and improves the context modeling design.Moreover,it improves the update process of predictive correction C[Q] on the prediction error calculation,which can reduce the occupation of logic resources,and improve the encoder clock frequency reaches 41 MHz that improving the compression efficiency and shortening the encoding time.Finally,the 16 bit random image data is used to carry out a comprehensive simulation verification,and realize the lossless compression of the image data.The results show that there is no difference in the contrast between the image data and the original image data.After a large number of tests,the correctness and robustness of the coding are verified,and the image lossless compression is accomplished efficiently,which makes all the indexes meet the established requirements.In addition,the main units of the image acquisition and processing system are tested,in which the image excitation source unit can send different types of image data according to different modes.The Cameralink image acquisition and processing unit can collect two Cameralink image data at the same time and carry out JPEG-LS lossless compression.The results show that the system achieves the effect of real-time image acquisition and lossless compression.