|
|
论文:2015,Vol:33,Issue(2):216-221 |
|
|
引用本文： |
|
|
赵斌, J. Guo, E. K. A. Gill, 周军. 一种基于交叉熵的黑白棋盘角点检测算法[J]. 西北工业大学学报 |
|
|
Zhao Bin, J. Guo, E. K. A. Gill, Zhou Jun. Chessboard Corner Detection Algorithm Based on Minimum Cross Entropy[J]. Northwestern polytechnical university |
|
|
|
|
|
|
|
| 一种基于交叉熵的黑白棋盘角点检测算法 |
|
| 赵斌1,2, J. Guo2, E. K. A. Gill2, 周军1 |
|
1. 西北工业大学精确制导与控制研究所, 陕西西安 710072;
2. Faculty of Aerospace Engineering, Delft University of Technology, Kluyverweg 1, 2629 HS Delft, The Netherlands |
| 摘要: |
| 分析了现有黑白棋盘角点检测算法存在的不足,将交叉熵思想引入角点检测中。该算法首先将角点周围像素划分为4个象限,通过相邻象限间的像素灰度差实现角点初选;其次,给出对角象限灰度交叉熵定义,根据局部交叉熵最小原理实现角点筛选;第3,针对备选角点局部重叠的问题,采用梯度幅值非极大值抑制方法实现像素级角点定位;最后采用Frostner算子实现角点的亚像素坐标解算。实验结果显示该算法检测结果优于经典Harris算子以及SV算子,获取的角点亚像素坐标精度与Matlab相机标定工具箱相当,同时易于实现在线标定。 |
| 关键词:
相机标定
棋盘角点检测
交叉熵
非极大值抑制
梯度幅值
|
|
| Chessboard Corner Detection Algorithm Based on Minimum Cross Entropy |
|
| Zhao Bin1,2, J. Guo2, E. K. A. Gill2, Zhou Jun1 |
|
1. Institute of Precision Guidance and Control, Northwestern Polytechnical University, Xi'an 710072, China;
2. Faculty of Aerospace Engineering, Delft University of Technology, Kluyverweg 1, 2629 HS Delft, The Netherlands |
| Abstract: |
| The shortcoming of the present B/W chessboard corner detection algorithm is analyzed and a new method based on cross entropy is proposed. Firstly, the pixels around the corner are divided into 4 quadrants, and initial selection of corners is carried out based on the gray value difference between the adjacent quadrants; secondly, the cross entropy of the diagonal quadrant is defined, and the corner screening is done using the principle of minimum cross entropy; thirdly, the idea of non-maximum suppression of local gradient amplitude is introduced to solve the problem of local overlap of the candidates; at last, sub-pixel coordinates of corners are calculated using Frostner Operator. Experiments and their analysis prove preliminarily that:(1) the detection result of this algorithm is better than the classical Harris Operator and SV Operator; (2) the sub-pixel accuracy obtained is almost the same as that obtained with the Matlab Camera Calibration Toolbox, and it is suitable for online camera calibration. |
| Key words:
algorithms
calibration
CCD cameras
entropy
flowcharting
interference suppression
mathematical operators
MATLAB
pixels
camera calibration
chess board corner detection
gradient amplitude
grey value difference
local overlap
non-maximum suppression
principle of minimum cross entropy
|
|
| 收稿日期: 2014-09-18
修回日期:
|
| DOI: |
| 基金项目: 西北工业大学基础研究基金(JCT20130101)资助 |
| 通讯作者:
Email： |
| 作者简介: 赵斌(1986-),西北工业大学讲师,主要从事飞行器制导控制及半实物仿真研究。
|
|
|
|
|
|
|
|
参考文献: |
|
|
[1] Andani Osuman. Multi-Robot Testbed for Distributed Space System[D]. Delft University of Technology, 2012
[2] Zhao B, Guo J, Gill E K A. A Camera-Based Positioning System for the Formation Flying Testbed[C] //Proceedings of the 63rd International Astronautical Congress, 2012:8325-8333
[3] Zhang Z. A Flexible New Technique for Camera Calibration[J]. IEEE Trans on Pattern Analysis and Machine Intelligence, 2000, 22:1330-1334
[4] Chris Harris, Mike Stephens. A Combined Corner and Edge Detector[C] //Proceedings of the 4th Alvey Vision Conference, Manchester, 1988:l47-l51
[5] Arturo de Laescalera, Jose Maria Armingol. Automatic Chessboard Detection for Intrinsic and Extrinsic Camera Parameter Calibration[J]. Sensors, 2010, 10:2027-2044
[6] Wang Zhongshi, Wu Wei, Xu Xinhe, et al. Recognition and Location of the Internal Corners of Planar Checkerboard Calibration Pattern Image[J]. Applied Mathematics and Computation, 2007, 185:894-906
[7] 刘阳成,朱枫.一种新的棋盘格图像角点检测算法[J].中国图像图形学报,2006,11(5):656-660 Liu Yangcheng, Zhu Feng. A New Algorithm for X-Corner Detection[J]. Journal of Image and Graphics, 2006, 11(5):656-660(in Chinese)
[8] 郝颖明,朱枫.摄像机在线标定中的棋盘格角点自动检测方法[J].计算机工程, 2007, 33(17):213-215 Hao Yingming, Zhu Feng. Automatic X-Corners Detection for Online Camera Calibration[J]. Computer Engineering, 2007, 33(17):213-215(in Chinese)
[9] 刘阳,王福利,常玉清,等.黑白棋盘格角点检测算法[J].东北大学学报,2007,28(8):1090-1093 Liu Yang, Wang Fuli, Chang Yuqing, et al. Black and White X-Corner Detection Algorithm[J]. Journal of Northeastern University, 2007, 28(8):1090-1093(in Chinese)
[10] He Juan, Xia Junying, Xu Xiaoquan, et al. Automatic Corner Detection and Localization for Camera Calibration[C] //The 10th International Conference on Electronic Measurement & Instruments, 2011:312-315
[11] Shi Xifan, Hong Ning, Cai Tiefeng. An Automatic and Robust Chessboard Corner Extraction[J]. LNCS Transactions on Edutainment 6758, 2011, 49-56
[12] Yu Chunsheng, Peng Qingjin. Robust Recognition of Checkerboard Pattern for Camera Calibration[J]. Optical Engineering, 2006, 45:093201
[13] 梁力,尹东斐,王川.高精度摄像机标定模板的设计及识别算法[J].西安交通大学学报,2011,45(4):82-85(in Chinese) Liang Li, Yin Dongfei, Wang Chuan. Design and Detection Methods for Accurate Camera Calibration Targets[J]. Journal of Xi'an Jiaotong University, 2011, 45(4):82-85(in Chinese)
[14] Jean-Yves Bouguet. Camera Calibration Toolbox for Matlab[EB/OL]. (2013-12-02)[2014-02-10]. http://www.vision.caltech.edu/bouguetj/calib_doc/index.html
[15] Gary Bradski, Adrian Kaehler:Learning Open CV[M]. USA, O'Reiuy Media, Inc, 2008
[16] Li C H, Lee C K. Minimum Cross Entropy Thresholding[J]. Pattern Recognition, 1993, 26:617-625
[17] John Canny. A Computational Approach to Edge Detection[J]. IEEE Trans on Pattern Analysis And Machine Intelligence, 1986, 8(6):679-698
[18] Gonzalez R C, Woods R E. Digital Image Processing[M]. 2nd ed, New Jersey, USA, Prentice Hall, 2002 |
|
|
|
|
|
|
|
