一个可以调节参数的形态学例题,用到的自定义核函数为:
- IplConvKernel * cvCreateStructuringElementEx(
- int cols,
- int rows,
- int anchor_x,
- int anchor_y,
- int shape,
- int *value=NULL
- );
函数中参数cols,rows确定了构造的矩形大小。
anchor_x,anchor_y确定了封闭矩形内参考点的横纵坐标。
shape是自定义核的形状,具体为
1.CV_SHAPE_RECT 核是矩形
2.CV_SHAPE_CROSS 核是勺子交叉形
3.CV_SHAPE_ELLIPSE 核是椭圆形
4.CV_SHAPE_CUSTOM 核是用户自定义类型
其释放函数为
- void cvReleaseStructuringElement( IplConvKernel **element);
实例代码如下:
- #include <cv.h>
- #include <highgui.h>
- #include <stdlib.h>
- #include <stdio.h>
- IplImage* src = 0;
- IplImage* dst = 0;
- IplConvKernel* element = 0;
- int element_shape = CV_SHAPE_RECT;
- //the address of variable which receives trackbar position update
- int max_iters = 10;
- int open_close_pos = 0;
- int erode_dilate_pos = 0;
- // callback function for open/close trackbar
- void OpenClose(int pos)
- {
- int n = open_close_pos - max_iters;
- int an = n > 0 ? n : -n;
- element = cvCreateStructuringElementEx( an*2+1, an*2+1, an, an, element_shape, 0 );
- if( n < 0 )
- {
- cvErode(src,dst,element,1);
- cvDilate(dst,dst,element,1);
- }
- else
- {
- cvDilate(src,dst,element,1);
- cvErode(dst,dst,element,1);
- }
- cvReleaseStructuringElement(&element);
- cvShowImage("Open/Close",dst);
- }
- // callback function for erode/dilate trackbar
- void ErodeDilate(int pos)
- {
- int n = erode_dilate_pos - max_iters;
- int an = n > 0 ? n : -n;
- element = cvCreateStructuringElementEx( an*2+1, an*2+1, an, an, element_shape, 0 );
- if( n < 0 )
- {
- cvErode(src,dst,element,1);
- }
- else
- {
- cvDilate(src,dst,element,1);
- }
- cvReleaseStructuringElement(&element);
- cvShowImage("Erode/Dilate",dst);
- }
-
- int main( int argc, char** argv )
- {
- char* filename = argc == 2 ? argv[1] : (char*)"baboon.jpg";
- if( (src = cvLoadImage(filename,1)) == 0 )
- return -1;
- printf( "Hot keys: \n"
- "\tESC - quit the program\n"
- "\tr - use rectangle structuring element\n"
- "\te - use elliptic structuring element\n"
- "\tc - use cross-shaped structuring element\n"
- "\tENTER - loop through all the options\n" );
- dst = cvCloneImage(src);
- //create windows for output images
- cvNamedWindow("Open/Close",1);
- cvNamedWindow("Erode/Dilate",1);
- open_close_pos = erode_dilate_pos = max_iters;
- cvCreateTrackbar("iterations", "Open/Close",&open_close_pos,max_iters*2+1,OpenClose);
- cvCreateTrackbar("iterations", "Erode/Dilate",&erode_dilate_pos,max_iters*2+1,ErodeDilate);
- for(;;)
- {
- int c;
-
- OpenClose(open_close_pos);
- ErodeDilate(erode_dilate_pos);
- c = cvWaitKey(0);
- if( (char)c == 27 )
- break;
- if( (char)c == 'e' )
- element_shape = CV_SHAPE_ELLIPSE;
- else if( (char)c == 'r' )
- element_shape = CV_SHAPE_RECT;
- else if( (char)c == 'c' )
- element_shape = CV_SHAPE_CROSS;
- else if( (char)c == '\n' )
- element_shape = (element_shape + 1) % 3;
- }
- //release images
- cvReleaseImage(&src);
- cvReleaseImage(&dst);
- //destroy windows
- cvDestroyWindow("Open/Close");
- cvDestroyWindow("Erode/Dilate");
- return 0;
- }
运行结果图为:
说明:
在此例题中开运算和闭运算都是通过腐蚀-膨胀来实现的,而在OpenCV中有封装好的开闭运算可以直接调用。该函数为
- void cvMorphologyEx(
- const CvArr * src,
- CvArr *dst,
- CvArr *temp,
- IplConvKernel *element,
- int operation,
- int iterations=1
- )
参考资料:
1.http://hi.baidu.com/shentuhongfeng/blog/item/077c2b63377dfc6c0c33fab8.html
2.学习OpenCV,于仕祺,刘瑞祯,清华大学出版社,134-139
本站仅提供存储服务,所有内容均由用户发布,如发现有害或侵权内容,请
点击举报。