Journal of South China University of Technology (Natural Science Edition) ›› 2013, Vol. 41 ›› Issue (1): 58-63.doi: 10.3969/j.issn.1000-565X.2013.01.009

• Electronics, Communication & Automation Technology • Previous Articles     Next Articles

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)

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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