Menu
I am trying to implement contours using the following code..
im = cv2.imread('C:\Users\Prashant\Desktop\T.jpg')
imgray = cv2.cvtColor(im,cv2.COLOR_BGR2GRAY)
ret,thresh = cv2.threshold(imgray,127,255,0)
image, contours, hierarchy = cv2.findContours(thresh,cv2.RETR_TREE,cv2.CHAIN_APPROX_SIMPLE)
img = cv2.drawContour(im, contours, -1, (0,255,0), 3)
cv2.imshow('Image1',img)
but i am continously getting the following error.
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "C:\Python27\lib\site-packages\spyderlib\widgets\externalshell\sitecustomize.py", line 540, in runfile
execfile(filename, namespace)
File "C:/Users/Prashant/.spyder2/.temp.py", line 17, in <module>
image, contours, hierarchy = cv2.findContours(thresh,cv2.RETR_TREE,cv2.CHAIN_APPROX_SIMPLE)
ValueError: need more than 2 values to unpack
do the function findContours need more arguments? wht could i do to correct it.
519
go through the first contour as it is listed until you hit the closest point. Then switch to the other list, starting from the closest point you go clockwise through the other contour until it is used up. switch back to the first contour and append the rest of their points. force them into cv2 contour format.
To put in simple words findContours detects change in the image color and marks it as contour. As an example, the image of number written on paper the number would be detected as contour. The part that you want to detect should be white like above numbers in 1st image.
In OpenCV 2, findContours returns just two values, contours and hierarchy. The error occurs when python tries to assign those two values to the three names given on left in this statement:
image, contours, hierarchy = cv2.findContours(thresh,cv2.RETR_TREE,cv2.CHAIN_APPROX_SIMPLE)
It now returns three values:
findContours(image, mode, method[, contours[, hierarchy[, offset]]])
return image, contours, hierarchy
21
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With
