diff --git a/doc/py_tutorials/py_imgproc/py_houghlines/py_houghlines.markdown b/doc/py_tutorials/py_imgproc/py_houghlines/py_houghlines.markdown index 0bfdcacb61..881cf2a29e 100644 --- a/doc/py_tutorials/py_imgproc/py_houghlines/py_houghlines.markdown +++ b/doc/py_tutorials/py_imgproc/py_houghlines/py_houghlines.markdown @@ -59,7 +59,7 @@ denotes they are the parameters of possible lines in the image. (Image courtesy: ![](images/houghlines2.jpg) -Hough Tranform in OpenCV +Hough Transform in OpenCV ========================= Everything explained above is encapsulated in the OpenCV function, \*\*cv2.HoughLines()\*\*. It simply returns an array of :math:(rho, @@ -78,7 +78,8 @@ gray = cv2.cvtColor(img,cv2.COLOR_BGR2GRAY) edges = cv2.Canny(gray,50,150,apertureSize = 3) lines = cv2.HoughLines(edges,1,np.pi/180,200) -for rho,theta in lines[0]: +for line in lines: + rho,theta = line[0] a = np.cos(theta) b = np.sin(theta) x0 = a*rho @@ -123,10 +124,9 @@ import numpy as np img = cv2.imread('dave.jpg') gray = cv2.cvtColor(img,cv2.COLOR_BGR2GRAY) edges = cv2.Canny(gray,50,150,apertureSize = 3) -minLineLength = 100 -maxLineGap = 10 -lines = cv2.HoughLinesP(edges,1,np.pi/180,100,minLineLength,maxLineGap) -for x1,y1,x2,y2 in lines[0]: +lines = cv2.HoughLinesP(edges,1,np.pi/180,100,minLineLength=100,maxLineGap=10) +for line in lines: + x1,y1,x2,y2 = line[0] cv2.line(img,(x1,y1),(x2,y2),(0,255,0),2) cv2.imwrite('houghlines5.jpg',img) diff --git a/samples/python2/houghlines.py b/samples/python2/houghlines.py index 5836bee547..abf25dd059 100755 --- a/samples/python2/houghlines.py +++ b/samples/python2/houghlines.py @@ -18,23 +18,25 @@ src = cv2.imread(fn) dst = cv2.Canny(src, 50, 200) cdst = cv2.cvtColor(dst, cv2.COLOR_GRAY2BGR) -# HoughLines() -# lines = cv2.HoughLines(dst, 1, math.pi/180.0, 50, np.array([]), 0, 0) -# a,b,c = lines.shape -# for i in range(b): -# rho = lines[0][i][0] -# theta = lines[0][i][1] -# a = math.cos(theta) -# b = math.sin(theta) -# x0, y0 = a*rho, b*rho -# pt1 = ( int(x0+1000*(-b)), int(y0+1000*(a)) ) -# pt2 = ( int(x0-1000*(-b)), int(y0-1000*(a)) ) -# cv2.line(cdst, pt1, pt2, (0, 0, 255), 3, cv2.LINE_AA) +if True: # HoughLinesP + lines = cv2.HoughLinesP(dst, 1, math.pi/180.0, 40, np.array([]), 50, 10) + a,b,c = lines.shape + for i in range(a): + cv2.line(cdst, (lines[i][0][0], lines[i][0][1]), (lines[i][0][2], lines[i][0][3]), (0, 0, 255), 3, cv2.LINE_AA) + +else: # HoughLines + lines = cv2.HoughLines(dst, 1, math.pi/180.0, 50, np.array([]), 0, 0) + a,b,c = lines.shape + for i in range(a): + rho = lines[i][0][0] + theta = lines[i][0][1] + a = math.cos(theta) + b = math.sin(theta) + x0, y0 = a*rho, b*rho + pt1 = ( int(x0+1000*(-b)), int(y0+1000*(a)) ) + pt2 = ( int(x0-1000*(-b)), int(y0-1000*(a)) ) + cv2.line(cdst, pt1, pt2, (0, 0, 255), 3, cv2.LINE_AA) -lines = cv2.HoughLinesP(dst, 1, math.pi/180.0, 50, np.array([]), 50, 10) -a,b,c = lines.shape -for i in range(b): - cv2.line(cdst, (lines[0][i][0], lines[0][i][1]), (lines[0][i][2], lines[0][i][3]), (0, 0, 255), 3, cv2.LINE_AA) cv2.imshow("source", src) cv2.imshow("detected lines", cdst)