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126 lines
3.6 KiB
Python
Executable File
126 lines
3.6 KiB
Python
Executable File
#!/usr/bin/python
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"""
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This program is demonstration for ellipse fitting. Program finds
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contours and approximate it by ellipses.
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Trackbar specify threshold parametr.
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White lines is contours. Red lines is fitting ellipses.
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Original C implementation by: Denis Burenkov.
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Python implementation by: Roman Stanchak
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"""
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import sys
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from opencv import cv
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from opencv import highgui
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image02 = None
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image03 = None
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image04 = None
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def process_image( slider_pos ):
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"""
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Define trackbar callback functon. This function find contours,
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draw it and approximate it by ellipses.
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"""
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stor = cv.cvCreateMemStorage(0);
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# Threshold the source image. This needful for cv.cvFindContours().
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cv.cvThreshold( image03, image02, slider_pos, 255, cv.CV_THRESH_BINARY );
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# Find all contours.
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nb_contours, cont = cv.cvFindContours (image02,
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stor,
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cv.sizeof_CvContour,
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cv.CV_RETR_LIST,
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cv.CV_CHAIN_APPROX_NONE,
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cv.cvPoint (0,0))
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# Clear images. IPL use.
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cv.cvZero(image02);
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cv.cvZero(image04);
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# This cycle draw all contours and approximate it by ellipses.
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for c in cont.hrange():
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count = c.total; # This is number point in contour
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# Number point must be more than or equal to 6 (for cv.cvFitEllipse_32f).
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if( count < 6 ):
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continue;
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# Alloc memory for contour point set.
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PointArray = cv.cvCreateMat(1, count, cv.CV_32SC2)
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PointArray2D32f= cv.cvCreateMat( 1, count, cv.CV_32FC2)
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# Get contour point set.
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cv.cvCvtSeqToArray(c, PointArray, cv.cvSlice(0, cv.CV_WHOLE_SEQ_END_INDEX));
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# Convert CvPoint set to CvBox2D32f set.
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cv.cvConvert( PointArray, PointArray2D32f )
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box = cv.CvBox2D()
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# Fits ellipse to current contour.
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box = cv.cvFitEllipse2(PointArray2D32f);
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# Draw current contour.
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cv.cvDrawContours(image04, c, cv.CV_RGB(255,255,255), cv.CV_RGB(255,255,255),0,1,8,cv.cvPoint(0,0));
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# Convert ellipse data from float to integer representation.
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center = cv.CvPoint()
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size = cv.CvSize()
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center.x = cv.cvRound(box.center.x);
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center.y = cv.cvRound(box.center.y);
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size.width = cv.cvRound(box.size.width*0.5);
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size.height = cv.cvRound(box.size.height*0.5);
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box.angle = -box.angle;
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# Draw ellipse.
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cv.cvEllipse(image04, center, size,
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box.angle, 0, 360,
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cv.CV_RGB(0,0,255), 1, cv.CV_AA, 0);
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# Show image. HighGUI use.
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highgui.cvShowImage( "Result", image04 );
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if __name__ == '__main__':
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argc = len(sys.argv)
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filename = "../c/stuff.jpg"
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if(argc == 2):
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filename = sys.argv[1]
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slider_pos = 70
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# load image and force it to be grayscale
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image03 = highgui.cvLoadImage(filename, 0)
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if not image03:
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print "Could not load image " + filename
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sys.exit(-1)
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# Create the destination images
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image02 = cv.cvCloneImage( image03 );
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image04 = cv.cvCloneImage( image03 );
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# Create windows.
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highgui.cvNamedWindow("Source", 1);
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highgui.cvNamedWindow("Result", 1);
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# Show the image.
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highgui.cvShowImage("Source", image03);
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# Create toolbars. HighGUI use.
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highgui.cvCreateTrackbar( "Threshold", "Result", slider_pos, 255, process_image );
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process_image( 1 );
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#Wait for a key stroke; the same function arranges events processing
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print "Press any key to exit"
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highgui.cvWaitKey(0);
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highgui.cvDestroyWindow("Source");
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highgui.cvDestroyWindow("Result");
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