OpenCV python: ValueError: too many values to unpack

I'm writing an opencv program and I found a script on another stackoverflow question: Computer Vision: Masking a human hand

When I run the scripted answer, I get the following error:

    Traceback (most recent call last):
        File "skinimagecontour.py", line 13, in <module>
        contours, _ = cv2.findContours(skin_ycrcb, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)
    ValueError: too many values to unpack

The code:

    import sys
    import numpy
    import cv2

    im = cv2.imread('Photos/test.jpg')
    im_ycrcb = cv2.cvtColor(im, cv2.COLOR_BGR2YCR_CB)

    skin_ycrcb_mint = numpy.array((0, 133, 77))
    skin_ycrcb_maxt = numpy.array((255, 173, 127))
    skin_ycrcb = cv2.inRange(im_ycrcb, skin_ycrcb_mint, skin_ycrcb_maxt)
    cv2.imwrite('Photos/output2.jpg', skin_ycrcb) # Second image

    contours, _ = cv2.findContours(skin_ycrcb, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)
    for i, c in enumerate(contours):
        area = cv2.contourArea(c)
        if area > 1000:
            cv2.drawContours(im, contours, i, (255, 0, 0), 3)
    cv2.imwrite('Photos/output3.jpg', im)

Any help is appreciated!

I got the answer from the OpenCV Stack Exchange site. Answer

THE ANSWER:

I bet you are using the current OpenCV's master branch: here the return statements have changed, see http://docs.opencv.org/modules/imgproc/doc/structural_analysis_and_shape_descriptors.html?highlight=findcontours.

Thus, change the corresponding line to read:

>     _, contours, _= cv2.findContours(skin_ycrcb, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)
>

Or: since the current trunk is still not stable and you probably will run in some more problems, you may want to use OpenCV's current stable version 2.4.9.

From: stackoverflow.com/q/25504964

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