The Design Of Dual-spectrum High-speed Iris Acquisition System Based On FPGA

Today,iris recognition technology in biometrics has the best stability,highest accuracy and best anti-counterfeiting properties.The ability to acquire high-speed and clear iris images directly affects the accuracy and speed of iris recognition.However,high-speed and clear iris images are determined by the imaging speed of the image sensor and the acquisition processing speed of the acquisition device.The CMOS infrared image sensor can realize high-speed iris imaging and make up for the unclear imaging of visible light sensor in low light scene,so as to ensure the quality of iris image information.FPGA can be used as the acquisition processing platform to collect,cache and process iris images at high speed.data.This paper mainly designs a high-speed iris acquisition system based on FPGA,which realizes real-time display of human iris image and detection of iris edge in human eye image.The main contents of this paper are as follows: 1.Complete the FPGA to drive the visible light and infrared image sensors;2.Complete the FPGA-based dual-channel image acquisition and display function module framework to obtain two high-speed real-time display images;Pre-processing of median filtering,Sobel edge detection,thresholding,etc.is performed on the acquired image;4.Hough transform is performed on the acquired iris image to detect the position of the inner and outer circle of the iris in the human eye image;5.For the Sobel edge detection The algorithm is optimized to obtain a more obvious iris edge image.The threshold value in the thresholding algorithm is adjusted by multiple simulation experiments to obtain a binary image with more obvious inner and outer irises.6.Finally,the traditional Hough transform circle detection algorithm is used.Based on the addition of pipeline processing and reducing the size of the accumulator array,reducing the excessive random access to the memory in the algorithm,the C simulation speed of the Hough transform circle detection is improved by 50~100 times,and the detection method using the small search range is greatly reduced.The traversal of pixels.Finally,through multiple hardware simulation experiments,300,000 pixels,60 frames of visible and infrared iris images can be obtained,and the positioning of the inner and outer circles of the iris in the human eye image under infrared imaging is realized.