Research and Implementation of Infrared Lens Auto-focus Technology Based on Field Programmable Gate Array
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摘要: 自动聚焦技术在红外热像仪监控领域有着非常重要的作用。目前业内红外自动聚焦技术存在聚焦成功率低、架构复杂、聚焦速度慢等状况,为此提出了一种基于FPGA的红外镜头自动聚焦技术,采用单FPGA实现了红外图像处理显示和自动聚焦的功能。鉴于红外图像普遍存在竖条纹噪声和随机噪声等特点,本文在实现聚焦过程中对红外清晰度评价算法和爬山算法做了改进和优化。实验结果表明本文提出的算法和实现方式能够很好地实现红外镜头的自动聚焦,同时具备集成度高、聚焦速度快、成功率高等特点,有比较广泛的应用前景。Abstract: Autofocus technology plays an important role in the field of infrared thermal imager monitoring. At present, there exist some problems with infrared auto focusing technology, such as low success rate, complex architecture and low focusing speed. Therefore, this study proposes an auto focusing technology of infrared lens based on FPGA, which realizes the functions of infrared image processing, display, and auto focusing with a single FPGA. In view of the common characteristics of vertical stripe noise and random noise in infrared images, this study improves and optimizes the infrared definition evaluation algorithm and mountain climbing algorithm in the focusing process. The experimental results show that the algorithm and implementation method proposed in this study can help infocusing on the infrared lens remarkably. Meanwhile, the proposed method has characteristics such as high integration, fast focusing speed, and high success rate, and thus has wide application prospects.
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Key words:
- infrared /
- autofocus /
- FPGA /
- definition evaluation /
- mountain climbing algorithm
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表 1 四幅画面的灰度方差值
Table 1. Gray variance of four pictures
Picture Picture description Gray variance Fig. 10(b) Original infrared image 2564.8 Fig. 10(c) Picture focused of Document[2] 2682.6 Fig. 10(d) Picture focused of Document[4] 2735.7 Fig. 10(e) Picture focused of this article 2842.2 表 2 FPGA资源消耗对比
Table 2. Comparison of FPGA resource consumption
Whole area calculation 1/3area calculation FPGA total resource LUT(num) 19405 9814 78600 LUTRAM(num) 6408 2061 26600 FF(num) 84852 13188 157200 Block RAM(num) 165 90 265 DSPs(num) 32 8 400 -
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