X-Git-Url: https://vcs.maemo.org/git/?a=blobdiff_plain;f=samples%2Fc%2Fsquares.c;h=79f2b7b4412f3d22ea26055ad766f993c157c06d;hb=e4c14cdbdf2fe805e79cd96ded236f57e7b89060;hp=fe9f363dcc61cbda4261857c5965868cc1cdc2d2;hpb=454138ff8a20f6edb9b65a910101403d8b520643;p=opencv diff --git a/samples/c/squares.c b/samples/c/squares.c index fe9f363..79f2b7b 100644 --- a/samples/c/squares.c +++ b/samples/c/squares.c @@ -7,6 +7,8 @@ #pragma package #endif +#define CV_NO_BACKWARD_COMPATIBILITY + #include "cv.h" #include "highgui.h" #include @@ -21,7 +23,7 @@ const char* wndname = "Square Detection Demo"; // helper function: // finds a cosine of angle between vectors -// from pt0->pt1 and from pt0->pt2 +// from pt0->pt1 and from pt0->pt2 double angle( CvPoint* pt1, CvPoint* pt2, CvPoint* pt0 ) { double dx1 = pt1->x - pt0->x; @@ -39,7 +41,7 @@ CvSeq* findSquares4( IplImage* img, CvMemStorage* storage ) int i, c, l, N = 11; CvSize sz = cvSize( img->width & -2, img->height & -2 ); IplImage* timg = cvCloneImage( img ); // make a copy of input image - IplImage* gray = cvCreateImage( sz, 8, 1 ); + IplImage* gray = cvCreateImage( sz, 8, 1 ); IplImage* pyr = cvCreateImage( cvSize(sz.width/2, sz.height/2), 8, 3 ); IplImage* tgray; CvSeq* result; @@ -47,35 +49,35 @@ CvSeq* findSquares4( IplImage* img, CvMemStorage* storage ) // create empty sequence that will contain points - // 4 points per square (the square's vertices) CvSeq* squares = cvCreateSeq( 0, sizeof(CvSeq), sizeof(CvPoint), storage ); - + // select the maximum ROI in the image // with the width and height divisible by 2 cvSetImageROI( timg, cvRect( 0, 0, sz.width, sz.height )); - + // down-scale and upscale the image to filter out the noise cvPyrDown( timg, pyr, 7 ); cvPyrUp( pyr, timg, 7 ); tgray = cvCreateImage( sz, 8, 1 ); - + // find squares in every color plane of the image for( c = 0; c < 3; c++ ) { // extract the c-th color plane cvSetImageCOI( timg, c+1 ); cvCopy( timg, tgray, 0 ); - + // try several threshold levels for( l = 0; l < N; l++ ) { // hack: use Canny instead of zero threshold level. - // Canny helps to catch squares with gradient shading + // Canny helps to catch squares with gradient shading if( l == 0 ) { // apply Canny. Take the upper threshold from slider - // and set the lower to 0 (which forces edges merging) + // and set the lower to 0 (which forces edges merging) cvCanny( tgray, gray, 0, thresh, 5 ); // dilate canny output to remove potential - // holes between edge segments + // holes between edge segments cvDilate( gray, gray, 0, 1 ); } else @@ -84,11 +86,11 @@ CvSeq* findSquares4( IplImage* img, CvMemStorage* storage ) // tgray(x,y) = gray(x,y) < (l+1)*255/N ? 255 : 0 cvThreshold( tgray, gray, (l+1)*255/N, 255, CV_THRESH_BINARY ); } - + // find contours and store them all as a list cvFindContours( gray, storage, &contours, sizeof(CvContour), CV_RETR_LIST, CV_CHAIN_APPROX_SIMPLE, cvPoint(0,0) ); - + // test each contour while( contours ) { @@ -107,7 +109,7 @@ CvSeq* findSquares4( IplImage* img, CvMemStorage* storage ) cvCheckContourConvexity(result) ) { s = 0; - + for( i = 0; i < 5; i++ ) { // find minimum angle between joint @@ -121,28 +123,28 @@ CvSeq* findSquares4( IplImage* img, CvMemStorage* storage ) s = s > t ? s : t; } } - + // if cosines of all angles are small // (all angles are ~90 degree) then write quandrange - // vertices to resultant sequence + // vertices to resultant sequence if( s < 0.3 ) for( i = 0; i < 4; i++ ) cvSeqPush( squares, (CvPoint*)cvGetSeqElem( result, i )); } - + // take the next contour contours = contours->h_next; } } } - + // release all the temporary images cvReleaseImage( &gray ); cvReleaseImage( &pyr ); cvReleaseImage( &tgray ); cvReleaseImage( &timg ); - + return squares; } @@ -153,26 +155,26 @@ void drawSquares( IplImage* img, CvSeq* squares ) CvSeqReader reader; IplImage* cpy = cvCloneImage( img ); int i; - + // initialize reader of the sequence cvStartReadSeq( squares, &reader, 0 ); - + // read 4 sequence elements at a time (all vertices of a square) for( i = 0; i < squares->total; i += 4 ) { CvPoint pt[4], *rect = pt; int count = 4; - + // read 4 vertices CV_READ_SEQ_ELEM( pt[0], reader ); CV_READ_SEQ_ELEM( pt[1], reader ); CV_READ_SEQ_ELEM( pt[2], reader ); CV_READ_SEQ_ELEM( pt[3], reader ); - - // draw the square as a closed polyline + + // draw the square as a closed polyline cvPolyLine( cpy, &rect, &count, 1, 1, CV_RGB(0,255,0), 3, CV_AA, 0 ); } - + // show the resultant image cvShowImage( wndname, cpy ); cvReleaseImage( &cpy ); @@ -198,14 +200,14 @@ int main(int argc, char** argv) continue; } img = cvCloneImage( img0 ); - + // create window and a trackbar (slider) with parent "image" and set callback - // (the slider regulates upper threshold, passed to Canny edge detector) + // (the slider regulates upper threshold, passed to Canny edge detector) cvNamedWindow( wndname, 1 ); - + // find and draw the squares drawSquares( img, findSquares4( img, storage ) ); - + // wait for key. // Also the function cvWaitKey takes care of event processing c = cvWaitKey(0); @@ -217,8 +219,8 @@ int main(int argc, char** argv) if( (char)c == 27 ) break; } - + cvDestroyWindow( wndname ); - + return 0; }