• Open Source Computer Vision Library

轮廓(contour)检测2

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运行结果

Image:Example-contours-image.pngImage:Example-contours-contours.png

代码

#ifdef _CH_
#pragma package <opencv>
#endif
 
#ifndef _EiC
#include "cv.h"
#include "cxcore.h"
#include "highgui.h"
#include <math.h>
#endif
 
#define w 500
int levels = 3;
CvSeq* contours = 0;
 
void on_trackbar(int pos)
{
    IplImage* cnt_img = cvCreateImage( cvSize(w,w), 8, 3 );
    CvSeq* _contours = contours;
    int _levels = levels - 3;
    if( _levels <= 0 ) // get to the nearest face to make it look more funny
        _contours = _contours->h_next->h_next->h_next;
    cvZero( cnt_img );
    cvDrawContours( cnt_img, _contours, CV_RGB(255,0,0), CV_RGB(0,255,0), _levels, 3, CV_AA, cvPoint(0,0) );
    cvShowImage( "contours", cnt_img );
    cvReleaseImage( &cnt_img );
}
 
int main( int argc, char** argv )
{
    int i, j;
    CvMemStorage* storage = cvCreateMemStorage(0);
    IplImage* img = cvCreateImage( cvSize(w,w), 8, 1 );
 
    cvZero( img );
 
    for( i=0; i < 6; i++ )
    {
        int dx = (i%2)*250 - 30;
        int dy = (i/2)*150;
        CvScalar white = cvRealScalar(255);
        CvScalar black = cvRealScalar(0);
 
        if( i == 0 )
        {
            for( j = 0; j <= 10; j++ )
            {
                double angle = (j+5)*CV_PI/21;
                cvLine(img, cvPoint(cvRound(dx+100+j*10-80*cos(angle)),
                    cvRound(dy+100-90*sin(angle))),
                    cvPoint(cvRound(dx+100+j*10-30*cos(angle)),
                    cvRound(dy+100-30*sin(angle))), white, 1, 8, 0);
            }
        }
 
        cvEllipse( img, cvPoint(dx+150, dy+100), cvSize(100,70), 0, 0, 360, white, -1, 8, 0 );
        cvEllipse( img, cvPoint(dx+115, dy+70), cvSize(30,20), 0, 0, 360, black, -1, 8, 0 );
        cvEllipse( img, cvPoint(dx+185, dy+70), cvSize(30,20), 0, 0, 360, black, -1, 8, 0 );
        cvEllipse( img, cvPoint(dx+115, dy+70), cvSize(15,15), 0, 0, 360, white, -1, 8, 0 );
        cvEllipse( img, cvPoint(dx+185, dy+70), cvSize(15,15), 0, 0, 360, white, -1, 8, 0 );
        cvEllipse( img, cvPoint(dx+115, dy+70), cvSize(5,5), 0, 0, 360, black, -1, 8, 0 );
        cvEllipse( img, cvPoint(dx+185, dy+70), cvSize(5,5), 0, 0, 360, black, -1, 8, 0 );
        cvEllipse( img, cvPoint(dx+150, dy+100), cvSize(10,5), 0, 0, 360, black, -1, 8, 0 );
        cvEllipse( img, cvPoint(dx+150, dy+150), cvSize(40,10), 0, 0, 360, black, -1, 8, 0 );
        cvEllipse( img, cvPoint(dx+27, dy+100), cvSize(20,35), 0, 0, 360, white, -1, 8, 0 );
        cvEllipse( img, cvPoint(dx+273, dy+100), cvSize(20,35), 0, 0, 360, white, -1, 8, 0 );
    }
 
    cvNamedWindow( "image", 1 );
    cvShowImage( "image", img );
 
    cvFindContours( img, storage, &contours, sizeof(CvContour),
                    CV_RETR_TREE, CV_CHAIN_APPROX_SIMPLE, cvPoint(0,0) );
 
    // comment this out if you do not want approximation
    contours = cvApproxPoly( contours, sizeof(CvContour), storage, CV_POLY_APPROX_DP, 3, 1 );
 
    cvNamedWindow( "contours", 1 );
    cvCreateTrackbar( "levels+3", "contours", &levels, 7, on_trackbar );
 
    on_trackbar(0);
    cvWaitKey(0);
    cvReleaseMemStorage( &storage );
    cvReleaseImage( &img );
 
    return 0;
}
 
#ifdef _EiC
main(1,"");
#endif

Python版本

#! /usr/bin/env python
 
print "OpenCV Python version of contours"
 
# import the necessary things for OpenCV
from opencv import cv
from opencv import highgui
 
# some default constants
_SIZE = 500
_DEFAULT_LEVEL = 3
 
# definition of some colors
_red = cv.cvScalar (0, 0, 255, 0);
_green = cv.cvScalar (0, 255, 0, 0);
_white = cv.cvRealScalar (255)
_black = cv.cvRealScalar (0)
 
# the callback on the trackbar, to set the level of contours we want
# to display
def on_trackbar (position):
 
    # create the image for putting in it the founded contours
    contours_image = cv.cvCreateImage (cv.cvSize (_SIZE, _SIZE), 8, 3)
 
    # compute the real level of display, given the current position
    levels = position - 3
 
    # initialisation
    _contours = contours
 
    if levels <= 0:
        # zero or negative value
        # => get to the nearest face to make it look more funny
        _contours = contours.h_next.h_next.h_next
 
    # first, clear the image where we will draw contours
    cv.cvSetZero (contours_image)
 
    # draw contours in red and green
    cv.cvDrawContours (contours_image, _contours,
                       _red, _green,
                       levels, 3, cv.CV_AA,
                       cv.cvPoint (0, 0))
 
    # finally, show the image
    highgui.cvShowImage ("contours", contours_image)
 
if __name__ == '__main__':
 
    # create the image where we want to display results
    image = cv.cvCreateImage (cv.cvSize (_SIZE, _SIZE), 8, 1)
 
    # start with an empty image
    cv.cvSetZero (image)
 
    # draw the original picture
    for i in range (6):
        dx = (i % 2) * 250 - 30
        dy = (i / 2) * 150
 
        cv.cvEllipse (image,
                      cv.cvPoint (dx + 150, dy + 100),
                      cv.cvSize (100, 70),
                      0, 0, 360, _white, -1, 8, 0)
        cv.cvEllipse (image,
                      cv.cvPoint (dx + 115, dy + 70),
                      cv.cvSize (30, 20),
                      0, 0, 360, _black, -1, 8, 0)
        cv.cvEllipse (image,
                      cv.cvPoint (dx + 185, dy + 70),
                      cv.cvSize (30, 20),
                      0, 0, 360, _black, -1, 8, 0)
        cv.cvEllipse (image,
                      cv.cvPoint (dx + 115, dy + 70),
                      cv.cvSize (15, 15),
                      0, 0, 360, _white, -1, 8, 0)
        cv.cvEllipse (image,
                      cv.cvPoint (dx + 185, dy + 70),
                      cv.cvSize (15, 15),
                      0, 0, 360, _white, -1, 8, 0)
        cv.cvEllipse (image,
                      cv.cvPoint (dx + 115, dy + 70),
                      cv.cvSize (5, 5),
                      0, 0, 360, _black, -1, 8, 0)
        cv.cvEllipse (image,
                      cv.cvPoint (dx + 185, dy + 70),
                      cv.cvSize (5, 5),
                      0, 0, 360, _black, -1, 8, 0)
        cv.cvEllipse (image,
                      cv.cvPoint (dx + 150, dy + 100),
                      cv.cvSize (10, 5),
                      0, 0, 360, _black, -1, 8, 0)
        cv.cvEllipse (image,
                      cv.cvPoint (dx + 150, dy + 150),
                      cv.cvSize (40, 10),
                      0, 0, 360, _black, -1, 8, 0)
        cv.cvEllipse (image,
                      cv.cvPoint (dx + 27, dy + 100),
                      cv.cvSize (20, 35),
                      0, 0, 360, _white, -1, 8, 0)
        cv.cvEllipse (image,
                      cv.cvPoint (dx + 273, dy + 100),
                      cv.cvSize (20, 35),
                      0, 0, 360, _white, -1, 8, 0)
 
    # create window and display the original picture in it
    highgui.cvNamedWindow ("image", 1)
    highgui.cvShowImage ("image", image)
 
    # create the storage area
    storage = cv.cvCreateMemStorage (0)
 
    # find the contours
    nb_contours, contours = cv.cvFindContours (image,
                                               storage,
                                               cv.sizeof_CvContour,
                                               cv.CV_RETR_TREE,
                                               cv.CV_CHAIN_APPROX_SIMPLE,
                                               cv.cvPoint (0,0))
 
    # comment this out if you do not want approximation
    contours = cv.cvApproxPoly (contours, cv.sizeof_CvContour,
                                storage,
                                cv.CV_POLY_APPROX_DP, 3, 1)
 
    # create the window for the contours
    highgui.cvNamedWindow ("contours", 1)
 
    # create the trackbar, to enable the change of the displayed level
    highgui.cvCreateTrackbar ("levels+3", "contours", 3, 7, on_trackbar)
 
    # call one time the callback, so we will have the 1st display done
    on_trackbar (_DEFAULT_LEVEL)
 
    # wait a key pressed to end
    highgui.cvWaitKey (0)
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