Effective subpixel edge detection for LED probes

The market of light-emitting devices (LED) is growing dramatically over these years. To test the quality of LEDs, lots of LED probes are required. Therefore, it is important to develop an effective method to measure the angle (around 10 degrees) and the radius (15 µm ∼ 30 µm) of a produced LED probe. In this study, we propose a new subpixel edge detection for LED probes. The proposed method mainly consists of a coarse edge detection by Canny operators and a fine edge detection by a reconstructive method. In addition, an Otsu thresholding and a reflecting-point removal are included to reduce noise and increase accuracy. Compared to the previous methods, the proposed method can further reduce angle error up to 19.5% and the radius error up to 24.8%, respectively.

[1]  Dandan Liu,et al.  Subpixel edge location based on orthogonal Fourier-Mellin moments , 2008, Image Vis. Comput..

[2]  Qu Ying-Dong,et al.  A fast subpixel edge detection method using Sobel-Zernike moments operator , 2005, Image Vis. Comput..

[3]  Shuen-De Wu,et al.  Sub-pixel edge detection of LED probes based on partial area effect , 2015, 2015 1st International Conference on Industrial Networks and Intelligent Systems (INISCom).

[5]  Agustín Trujillo-Pino,et al.  Accurate subpixel edge location based on partial area effect , 2013, Image Vis. Comput..

[6]  John F. Canny,et al.  A Computational Approach to Edge Detection , 1986, IEEE Transactions on Pattern Analysis and Machine Intelligence.

[7]  Sugata Ghosal,et al.  Orthogonal moment operators for subpixel edge detection , 1993, Pattern Recognit..

[8]  G. G. Stokes.  "J." , 1890, The New Yale Book of Quotations.

[9]  Anna Fabijanska,et al.  A survey of subpixel edge detection methods for images of heat-emitting metal specimens , 2012, Int. J. Appl. Math. Comput. Sci..