OpenCV使用边缘提取、腐蚀、轮廓进行车牌定位
http://blog.csdn.net/superdont/article/details/24935383
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采用OpenCV249利用边缘检测、轮廓检测、腐蚀实现的车牌定位,具体为:
- Mat srcImage=imread("image/000.jpg");
- //imshow("a",srcImage);
- int i,j;
- int cPointR,cPointG,cPointB,cPoint;//currentPoint;
- Mat resizeImage;
- resize(srcImage,resizeImage,Size(400,300));
- Mat grayImage;
- cvtColor(resizeImage,grayImage, CV_BGR2GRAY);
- Mat medianImage;
- medianBlur(grayImage,medianImage,3); //最后一个参数需要为奇数
- Mat sobelImage;
- //参数为:源图像,结果图像,图像深度,x方向阶数,y方向阶数,核的大小,尺度因子,增加的值
- Sobel(medianImage,sobelImage,CV_8U,1,0,3,0.4,128);
- Mat normalizeImage;
- normalize(sobelImage,normalizeImage,255,0,CV_MINMAX);
- Mat binaryImage;
- threshold(normalizeImage,binaryImage, 100, 255, THRESH_BINARY_INV );
- Mat closeImage;
- //morphologyEx(binaryImage,closeImage,MORPH_CLOSE,Mat(3,1,CV_8U),Point(0,0),10); //闭运算
- Mat openImage(closeImage.rows,closeImage.cols,CV_8UC1);
- //morphologyEx(closeImage,openImage,MORPH_OPEN,Mat(3,3,CV_8U),Point(0,0),1); //开运算
- // erode(openImage,openImage,Mat(3,3,CV_8U),Point(-1,-1),10);
- dilate(binaryImage,openImage,Mat(3,3,CV_8U),Point(-1,-1),6);
- /*
- Mat rgbImage;
- cvtColor(openImage,rgbImage, CV_GRAY2BGR);
- */
- //cvtColor(openImage,openImage, CV_BGR2GRAY);
- //vector<vector<Point> > contours;
- //vector<Vec4i> hierarchy;
- //openImage=imread("test.png");
- imshow("openImage",openImage);
- /// Detect edges using canny
- // Canny( src_gray, canny_output, thresh, thresh*2, 3 );
- /// Find contours
- /* Mat thresholdImage;
- cvtColor(openImage,openImage, CV_BGR2GRAY);
- threshold( openImage,thresholdImage,127, 255, THRESH_BINARY );
- openImage=thresholdImage;*/
- vector<vector<Point> > contours;
- vector<Vec4i> hierarchy;
- findContours(openImage, contours, hierarchy, CV_RETR_EXTERNAL, CV_CHAIN_APPROX_SIMPLE, Point(0, 0) );
- Scalar color = Scalar( rng.uniform(0, 255), rng.uniform(0,255), rng.uniform(0,255) );
- for( int i = 0; i < contours.size(); i++ )
- {
- //使用边界框的方式
- CvRect aRect = boundingRect(contours[i]);
- int tmparea=aRect.height*aRect.height;
- if (((double)aRect.width/(double)aRect.height>2)&& ((double)aRect.width/(double)aRect.height<6)&& tmparea>=200&&tmparea<=25000)
- {
- rectangle(resizeImage,cvPoint(aRect.x,aRect.y),cvPoint(aRect.x+aRect.width ,aRect.y+aRect.height),color,2);
- //cvDrawContours( dst, contours, color, color, -1, 1, 8 );
- }
- }
- imshow("contour",resizeImage);
效果一般,部分测试图像:
测试了很多图片,这几张基本有个样子,通过调整腐蚀的次数,可以针对不同的图像进行定位。
参考资料:
学习OpenCV——车牌检测(定位):http://blog.csdn.net/yangtrees/article/details/7444470