基于FPGA的低照度图像采集与处理系统研究

柳磊; 钱芸生

基于FPGA的低照度图像采集与处理系统研究

柳磊,
钱芸生^,

南京理工大学电子工程与光电技术学院, 江苏南京 210094

基金项目: 国防科技微光重点实验室基金

详细信息

作者简介:
柳磊（1996-），女，硕士研究生，主要从事光电成像科研工作。E-mail：liulei00000416@163.com

通讯作者:
钱芸生（1968-），男，教授，博士生导师。主要从事光电测试、图像处理和仿真等工作。E-mail：yshqian2015@163.com

中图分类号: TN223
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- 被引次数: 0
出版历程
- 收稿日期: 2021-06-17
- 修回日期: 2021-09-23
- 刊出日期: 2022-05-20

A Low Illumination Image Acquisition and Processing System Based on FPGA

LIU Lei,
QIAN Yunsheng^,

School of Electronic and Optical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China

摘要

摘要: 针对低照度图像亮度低、噪声高和边缘模糊等问题，基于Xilinx公司的Artix-7系列FPGA芯片，通过驱动微光性能良好的XQE-1310图像传感器，对探测器采集的视频信号进行滤波和边缘检测，完成了低照度图像的采集和处理等一系列操作，最后将处理过的视频信号通过CameraLink视频格式实时显示，设计了一套微光夜视系统。实验结果表明，该系统的最低工作照度可达10^－2 lx量级，滤波算法在保持图像边缘信息的同时有效滤除了图像中的椒盐噪声，自适应边缘检测算法可以根据照度水平实时调整阈值，凸显了低照度环境下物体的轮廓信息。系统充分利用了FPGA（Field Programmable Gate Array）速度快、效率高的优势，最后的成像结果清晰稳定，便于人眼观察。
- 低照度图像 /
- 滤波 /
- 边缘检测 /
- FPGA
Abstract: In terms of the problems of low brightness, high noise and blurred edges in low-illumination images, based on Xilinx's Artix-7 series FPGA chip, the XQE-1310 image sensor with good low-light performance is driven to filter and edge the video signal collected by the detector. After the detection, a series of operations such as acquisition and processing of low-light images were completed, and the processed video signals were displayed in real time through the CameraLink video format. Finally, a low-light night vision system was designed. The experimental results show that the minimum working illuminance of the system can reach the order of 10^-2 lx. The filtering algorithm can effectively filter the salt and pepper noise in the image while maintaining the edge information of the image. The adaptive edge detection algorithm can adjust the threshold in real time according to the illuminance level. It highlights the contour information of objects in low-light environments. The system makes full use of the advantages of fast speed and high efficiency of FPGA (Field Programmable Gate Array), and the final imaging result is clear and stable, which is convenient for human eyes to observe.
- low-illumination image /
- filter /
- edge detection /
- FPGA

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图 1 微光夜视系统总体框架设计

Figure 1. Low-light night vision system overall framework design

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图 2 IIC写操作时序图

Figure 2. IIC write operation timing diagram

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图 3 IIC测试时序信号

Figure 3. IIC test timing signal

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图 4 中值滤波流程图

Figure 4. Median filtering flowchart

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图 5 3×3窗口仿真波形

Figure 5. 3×3 Window Simulation Waveform

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图 6 静态图像中值滤波结果显示

Figure 6. Median filtering result display of static image

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图 7 边缘检测流程图

Figure 7. Edge detection flowchart

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图 8 Sobel算子卷积模板

Figure 8. Sobel operator convolution template

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图 9 静态图像边缘检测结果显示

Figure 9. Static image edge detection result display

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图 10 Channel Link操作图

Figure 10. Channel Link operation

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图 11 实验结果图

Figure 11. Experimental result

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图 12 FPGA中值滤波和边缘检测模块仿真波形

Figure 12. Simulation waveform of median filter and edge detection module

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表 1 软件和硬件中值滤波算法结果比较

Table 1. Comparison of the results of software and hardware median filtering algorithms

Parameters NMSE PSNR/dB

MATLAB 0.0706 39.3956

FPGA 0.0710 39.3653

下载: 导出CSV

参考文献(13)

[1]	方明, 李洪娜, 雷立宏, 等. 低照度视频图像增强算法综述[J]. 长春理工大学学报: 自然科学版, 2016, 39(3): 56-64, 69. doi: 10.3969/j.issn.1672-9870.2016.03.013 FANG Ming, LI Hongna, LEI Lihong, et al. Overview of low-light video image enhancement algorithms[J]. Journal of Changchun University of Science and Technology: Natural Science Edition, 2016, 39(3): 56-64, 69. doi: 10.3969/j.issn.1672-9870.2016.03.013
[2]	赵红伟, 刘凯丽, 张伟, 等. 基于FPGA的光电成像与显示电路设计[J]. 光电子技术, 2019, 39(3): 205-209. https://www.cnki.com.cn/Article/CJFDTOTAL-GDJS201903010.htm ZHAO Hongwei, LIU Kaili, ZHANG Wei, et al. Design of photoelectric imaging and display circuit based on FPGA[J]. Optoelectronic Technology, 2019, 39(3): 205-209. https://www.cnki.com.cn/Article/CJFDTOTAL-GDJS201903010.htm
[3]	朱虹. 数字图像处理基础[M]. 北京: 科学出版社, 2005. ZHU Hong. Fundamentals of Digital Image Processing[M]. Beijing: Science Press, 2005.
[4]	韩团军. 快速中值滤波算法研究及其FPGA硬件实现[J]. 电子器件, 2017, 40(3): 697-701. doi: 10.3969/j.issn.1005-9490.2017.03.036 HAN Tuanjun. Research on Fast Median Filter Algorithm and Its FPGA Hardware Implementation[J]. Electronic Devices, 2017, 40(3): 697-701. doi: 10.3969/j.issn.1005-9490.2017.03.036
[5]	黄梦涛, 胡永才. 改进自适应中值滤波的低照度烟雾图像去噪[J]. 计算机工程与设计, 2018, 39(6): 1659-1663. https://www.cnki.com.cn/Article/CJFDTOTAL-SJSJ201806028.htm HUANG Mengtao, HU Yongcai. Improved adaptive median filter denoising in smoking image of low illumination[J]. Computer Engineering and Design, 2018, 39(6): 1659-1663. https://www.cnki.com.cn/Article/CJFDTOTAL-SJSJ201806028.htm
[6]	Gonzalez R C, Woods R E. Digital Image Processing[M]. 3^rd Edition, Beijing Publishing House of Electronics Industry, 2011: 445-465.
[7]	叶惠娇, 冉全, 成果. FPGA图像边缘检测系统的设计与实现[J]. 计算机应用与软件, 2018, 35(12): 237-240, 302. https://www.cnki.com.cn/Article/CJFDTOTAL-JYRJ201812044.htm YE Huijiao, RAN Quan, CHENG Guo. Design and Implementation of FPGA Image Edge Detection System[J]. Computer Applications and Software, 2018, 35(12): 237-240, 302. https://www.cnki.com.cn/Article/CJFDTOTAL-JYRJ201812044.htm
[8]	杨帆, 张皓, 马新文, 等. 基于FPGA的图像处理系统[J]. 华中科技大学学报: 自然科学版, 2015, 43(2): 119-123. https://www.cnki.com.cn/Article/CJFDTOTAL-HZLG201502025.htm YANG Fan, ZHANG Hao, MA Xinwen, et al. Image processing system based on FPGA[J]. Journal of Huazhong University of Science and Technology: Natural Science Edition, 2015, 43(2): 119-123. https://www.cnki.com.cn/Article/CJFDTOTAL-HZLG201502025.htm
[9]	林源晟. 基于FPGA的图像边缘检测系统设计[D]. 西安: 西安电子科技大学, 2014. LIN Yuansheng. FPGA-Based Image Edge Detection System Design[D]. Xi'an: Xidian University, 2014.
[10]	毛栋. 基于FPGA的高速CMOS成像系统设计[D]. 西安: 中国科学院大学(中国科学院西安光学精密机械研究所), 2019. MAO Dong. Design of High-speed CMOS Imaging System Based on FPGA[D]. Xi'an: University of Chinese Academy of Sciences (Xi'an Institute of Optics and Fine Mechanics, Chinese Academy of Sciences), 2019.
[11]	磨少清. 边缘检测及其评价方法的研究[D]. 天津: 天津大学, 2011. MO Shaoqing. Research on Edge Detection and Its Evaluation Method[D]. Tianjin: Tianjin University, 2011.
[12]	陈炳文, 王文伟, 梅天灿, 等. 利用比例分解和嵌套窗口进行彩色图像边缘提取[J]. 武汉大学学报: 信息科学版, 2011, 36(6): 695-698. https://www.cnki.com.cn/Article/CJFDTOTAL-WHCH201106016.htm CHEN Bingwen, WANG Wenwei, MEI Tiancan, et al. Using scale decomposition and nested windows for color image edge extraction[J]. Journal of Wuhan University: Information Science Edition, 2011, 36(6): 695-698. https://www.cnki.com.cn/Article/CJFDTOTAL-WHCH201106016.htm
[13]	黄德天, 刘雪超, 吴志勇, 等. 基于CameraLink的高速图像采集处理系统设计[J]. 吉林大学学报: 工学版, 2013, 43(S1): 309-312. https://www.cnki.com.cn/Article/CJFDTOTAL-JLGY2013S1066.htm HUANG Detian, LIU Xuechao, WU Zhiyong, et al. Design of high-speed image acquisition and processing system based on Camera Link[J]. Journal of Jilin University: Engineering and Technology Edition, 2013, 43(S1): 309-312. https://www.cnki.com.cn/Article/CJFDTOTAL-JLGY2013S1066.htm