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fixed spelling and removed return images

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This commit is contained in:
Martin Dlouhy 2014-02-10 20:32:54 +01:00
parent 86b6c48712
commit 47a41449e3
1 changed files with 5 additions and 5 deletions
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doc/py_tutorials/py_imgproc/py_contours/py_contours_begin/py_contours_begin.rst
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@ -28,9 +28,9 @@ Let's see how to find contours of a binary image:
im = cv2.imread('test.jpg') im = cv2.imread('test.jpg')
imgray = cv2.cvtColor(im,cv2.COLOR_BGR2GRAY) imgray = cv2.cvtColor(im,cv2.COLOR_BGR2GRAY)
ret,thresh = cv2.threshold(imgray,127,255,0) ret,thresh = cv2.threshold(imgray,127,255,0)
image, contours, hierarchy = cv2.findContours(thresh,cv2.RETR_TREE,cv2.CHAIN_APPROX_SIMPLE) contours, hierarchy = cv2.findContours(thresh,cv2.RETR_TREE,cv2.CHAIN_APPROX_SIMPLE)
See, there are three arguments in **cv2.findContours()** function, first one is source image, second is contour retrieval mode, third is contour approximation method. And it outputs the image, contours and hierarchy. ``contours`` is a Python list of all the contours in the image. Each individual contour is a Numpy array of (x,y) coordinates of boundary points of the object. See, there are three arguments in **cv2.findContours()** function, first one is source image, second is contour retrieval mode, third is contour approximation method. And it outputs the contours and hierarchy. ``contours`` is a Python list of all the contours in the image. Each individual contour is a Numpy array of (x,y) coordinates of boundary points of the object.
.. note:: We will discuss second and third arguments and about hierarchy in details later. Until then, the values given to them in code sample will work fine for all images. .. note:: We will discuss second and third arguments and about hierarchy in details later. Until then, the values given to them in code sample will work fine for all images.
@ -43,18 +43,18 @@ To draw the contours, ``cv2.drawContours`` function is used. It can also be used
To draw all the contours in an image: To draw all the contours in an image:
:: ::
img = cv2.drawContour(img, contours, -1, (0,255,0), 3) cv2.drawContours(img, contours, -1, (0,255,0), 3)
To draw an individual contour, say 4th contour: To draw an individual contour, say 4th contour:
:: ::
img = cv2.drawContours(img, contours, 3, (0,255,0), 3) cv2.drawContours(img, contours, 3, (0,255,0), 3)
But most of the time, below method will be useful: But most of the time, below method will be useful:
:: ::
cnt = contours[4] cnt = contours[4]
img = cv2.drawContours(img, [cnt], 0, (0,255,0), 3) cv2.drawContours(img, [cnt], 0, (0,255,0), 3)
.. note:: Last two methods are same, but when you go forward, you will see last one is more useful. .. note:: Last two methods are same, but when you go forward, you will see last one is more useful.