Acquisition And Transmission System Of Digital Image Based On Camera Link And Ethernet

With the development of image sensor frame rate and resolution improvement,image sensor in the industrial, agricultural and military field of high-end application hasbecome more and more widely used, the acquisition, which has put forward higherrequirements to the transmission speed of image. Camera Link is an image data businterface standard with high transmission speed and long transmission distance andmost cameras are equipped with this kind of interface as the image data output channel.The Ethernet technology, as the most widely installed local area network technology,has developed a high-speed transfer mode including Fast Ethernet, Gigabit Ethernet,and10Gigabit Ethernet. Camera Link interface and Ethernet interface which are bothsuitable for high-speed, large-volume data transmission of image data, can satisfy thematching problem between the output image sensor and computer terminal velocity.This paper, based on the Camera Link interface and Ethernet technology, designs aset of image acquisition and transmission system. The system uses the FPGA AlteraCyclone II EP2C35F672C6model (Field Programmable Gate Array) as the timingcontrol, image data acquisition and processing, the ARM Cortex-M4kernel basedfreesale K60microcontroller as the control center, and employes DS90CR284chip toconvert Camera Link signals into digital signals. The image, through the SDRAM cachematched by FPGA, is transferred into PC through Ethernet via the DMA channel of theARM Cortex-M4microcontroller, and finally received, stored and displayed by thecomputer specialized software.This paper comprehensively studies the Camera Link interface technology and thelow-voltage differential signaling (LVDS) technology, detailedly explains the contentand operating law of the Ethernet protocol, uses the UDP protocol to transmit data andconstructs the acquisition and transmission system of digital image based on CameraLink and Ethernt, Then it designs the individual hardware modules of the systemincluding: a Camera Link Interface Module, K60microcontroller module and Ethernetcommunication module. At the same time, it develops the supporting underlying driversand uses Visual C/C++6.0and OpenCV image processing library to design a PCsoftware.In order to test the function of the system, the paper also designs a camera modulebased on the OV7620CMOS image sensor, chooses the DS90CR283chip to convert the image signal to Camera Link signal, and finally completes the image datatransmission from the camera, to the image acquisition card, then to the data memory ofPC.