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changed code in python tutorial, these functions don’t return image

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Alexander Shishkov 2014-01-11 16:35:41 +04:00
parent 5a9900481a
commit e90d0b6e4c
1 changed files with 6 additions and 6 deletions
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12
doc/py_tutorials/py_gui/py_drawing_functions/py_drawing_functions.rst
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@ -33,21 +33,21 @@ To draw a line, you need to pass starting and ending coordinates of line. We wil
img = np.zeros((512,512,3), np.uint8)
# Draw a diagonal blue line with thickness of 5 px
img = cv2.line(img,(0,0),(511,511),(255,0,0),5)
cv2.line(img,(0,0),(511,511),(255,0,0),5)
Drawing Rectangle
-------------------
To draw a rectangle, you need top-left corner and bottom-right corner of rectangle. This time we will draw a green rectangle at the top-right corner of image.
::
img = cv2.rectangle(img,(384,0),(510,128),(0,255,0),3)
cv2.rectangle(img,(384,0),(510,128),(0,255,0),3)
Drawing Circle
----------------
To draw a circle, you need its center coordinates and radius. We will draw a circle inside the rectangle drawn above.
::
img = cv2.circle(img,(447,63), 63, (0,0,255), -1)
cv2.circle(img,(447,63), 63, (0,0,255), -1)
Drawing Ellipse
--------------------
@ -55,7 +55,7 @@ Drawing Ellipse
To draw the ellipse, we need to pass several arguments. One argument is the center location (x,y). Next argument is axes lengths (major axis length, minor axis length). ``angle`` is the angle of rotation of ellipse in anti-clockwise direction. ``startAngle`` and ``endAngle`` denotes the starting and ending of ellipse arc measured in clockwise direction from major axis. i.e. giving values 0 and 360 gives the full ellipse. For more details, check the documentation of **cv2.ellipse()**. Below example draws a half ellipse at the center of the image.
::
img = cv2.ellipse(img,(256,256),(100,50),0,0,180,255,-1)
cv2.ellipse(img,(256,256),(100,50),0,0,180,255,-1)
Drawing Polygon
@ -65,7 +65,7 @@ To draw a polygon, first you need coordinates of vertices. Make those points int
pts = np.array([[10,5],[20,30],[70,20],[50,10]], np.int32)
pts = pts.reshape((-1,1,2))
img = cv2.polylines(img,[pts],True,(0,255,255))
cv2.polylines(img,[pts],True,(0,255,255))
.. Note:: If third argument is ``False``, you will get a polylines joining all the points, not a closed shape.
@ -103,4 +103,4 @@ Additional Resources
Exercises
==============
#. Try to create the logo of OpenCV using drawing functions available in OpenCV
#. Try to create the logo of OpenCV using drawing functions available in OpenCV.