华南理工大学学报(自然科学版) ›› 2013, Vol. 41 ›› Issue (1): 58-63.doi: 10.3969/j.issn.1000-565X.2013.01.009

• 电子、通信与自动控制 • 上一篇    下一篇

高温物体成像时彩色CCD 相机的自动调光方法

李哲林1,2 夏琴香1 姜立军2 李一振3 宋阿生3   

  1. 1. 华南理工大学 机械与汽车工程学院, 广东 广州 510640; 2. 华南理工大学 设计学院, 广东 广州 510006;3. 广州造船厂有限公司, 广东 广州 510382
  • 收稿日期:2012-03-31 修回日期:2012-09-05 出版日期:2013-01-25 发布日期:2012-12-03
  • 通信作者: 李哲林(1974-),男,在职博士生,副教授,主要从事图像处理、测量技术研究. E-mail:zhelinli@scut.edu.cn
  • 作者简介:李哲林(1974-),男,在职博士生,副教授,主要从事图像处理、测量技术研究.
  • 基金资助:

    广东省重大科技专项(2009A080304004);华南理工大学中央高校基本科研业务费专项资金资助项目(2011ZM0109)

Automatic Light Adjustment Method for Color CCD Camera Usedin Imaging of High-Temperature Object

Li Zhe-lin1,2 Xia Qin-xiang1 Jiang Li-jun2 Li Yi-zhen3 Song A-sheng3   

  1. 1. School of Mechanical and Automotive Engineering, South China University of Technology, Guangzhou 510640, Guangdong, China;2. School of Design, South China University of Technology, Guangzhou 510006, Guangdong, China;3. Guangzhou Shipyard Company Limited, Guangzhou 510382, Guangdong, China
  • Received:2012-03-31 Revised:2012-09-05 Online:2013-01-25 Published:2012-12-03
  • Contact: 李哲林(1974-),男,在职博士生,副教授,主要从事图像处理、测量技术研究. E-mail:zhelinli@scut.edu.cn
  • About author:李哲林(1974-),男,在职博士生,副教授,主要从事图像处理、测量技术研究.
  • Supported by:

    广东省重大科技专项(2009A080304004);华南理工大学中央高校基本科研业务费专项资金资助项目(2011ZM0109)

摘要: 针对温度变化大的高温物体在CCD 相机上成像时图像会发白或发黑,导致图像中物体特征被弱化这一问题,提出一种基于灰度均值的彩色CCD 相机自动调光方法. 文中首先阐述了CCD 相机成像时物体热辐射对图像灰度的影响;然后分析了彩色CCD 相机采集的850 ~1200℃高温物体图像的特点,建立了RGB 基色图像灰度均值与积分时间的关系;最后提出一种自动调光方法,该方法通过采集一帧预测图像来计算物体所在的温度区间和最佳积分时间,根据最佳积分时间采集彩色图像,按照温度区间提取彩色图像对应的基色灰度图,并将其作为后续处理图像. 实验结果表明,该调光方法对温度变化具有很好的鲁棒性,基于此方法的彩色CCD 相机能采集到具有稳定灰度值的高温物体图像,有利于高温物体的几何测量和表面缺陷检测.

关键词: 彩色CCD 相机, 高温物体, 调光, 积分时间, 灰度均值

Abstract:

Due to the whitened or darkened CCD camera images of high-temperature objects with wide temperaturechange range, the object features in the images are weakened. In order to solve this problem, an automatic lightadjustment method based on average gray value for color CCD camera is proposed. In the investigation, first, theeffects of object heat radiation on the image gray during the imaging are discussed. Next, the image features of theobject with the temperature of 8501200℃are analyzed. Then, the relationship between the average gray of RGBprimary color images and the integral time is revealed. Finally, an automatic light adjustment method is constructed,which calculates the temperature zone and optimal integral time by using a prediction image frame, acquires thecolor image according to the optimal integral time, and extracts a proper primary gray image from the color imagebased on temperature zone for further usage. Experimental results show that the proposed method is robust to widetemperature change range and helps to acquire images with stable average gray value of high-temperature objects,which benefits the geometry measurement and surface defect detection of high-temperature objects.

Key words: color CCD camera, high-temperature object, light adjustment, integral time, average gray value