Problem with cv2.drawKeypoints in version 4.0.0.21

[LaurentBerger]

system windows 10 msvc 2017 python 3.6.6

Hi,

It seems that some users have got some problem with drawKeypoints (http://answers.opencv.org/question/206950/function-drawkeypoints-do-not-work-in-opencv-401/ and http://answers.opencv.org/question/207758/drawkeypoints-bug/) using this code

import cv2
import numpy as np

def draw_keypoints(vis, keypoints, color = (0, 255, 255)):
    for kp in keypoints:
        x, y = kp.pt
        cv2.circle(vis, (int(x), int(y), 2, color))

input_image = cv2.imread('lena.jpg')
if input_image is None:
    print("check file path")
    exit()
gray_image = cv2.cvtColor(input_image, cv2.COLOR_BGR2GRAY)

orb = cv2.ORB_create()

keypoints = orb.detect(gray_image, None)

keypoints, descriptor = orb.compute(gray_image, keypoints)

t= cv2.drawKeypoints(input_image, keypoints, outImage=input_image, color=(0,255,0),
                          flags=cv2.DRAW_MATCHES_FLAGS_DRAW_RICH_KEYPOINTS)

cv2.imshow('ORB keypoints', input_image)
cv2.waitKey()

Error is AttributeError: module 'cv2.cv2' has no attribute 'drawKeypoints'

If i use my own version opencv-python there is no problem. Something is wrong but what ?

may be opencv/opencv#10250

[skvark]

This seems to be a bug in the binding generators in the upstream? You will have to wait that I have time to make a release for version 4.0.1 as it seems that the bug was fixed between 4.0.0 and 4.0.1 releases.

[LaurentBerger]

Yes it is fixed now. Some users wait the new release. As moderator on answers.opencv.org I can give an explanation.

Thanks

[woctezuma]

Thanks for your work on opencv-python.

I encounter the same issue.

In the meantime, I have worked around the issue by editing my code: I have replaced each call to drawKeypoints() with several calls to drawMarker().

For instance, in the tutorial:

img2 = cv.drawKeypoints(img, kp, None, color=(0,255,0), flags=0)
plt.imshow(img2), plt.show()

with:

img2 = img.copy()
for marker in kp:
	img2 = cv.drawMarker(img2, tuple(int(i) for i in marker.pt), color=(0, 255, 0))
plt.imshow(img2), plt.show()

[skvark]

This issue should be fixed in 4.0.1 but unfortunately I cannot release 4.0.1 before macOS build issues have been solved.

[Stephanehk]

Do you know when 4.0.1 might be released? Thanks

[wipix]

Hello ,
I had a question about the version available : when I run pip install opencv-python on my Rpi 3B+ : it installs opencv 3.4 .. but here it's said the current version is 4.0 ( " opencv-python 4.0.0.21 " // https://pypi.org/project/opencv-python/ ) .
(In fact I first tried for 3 days to compil myself a 4.0.0 build, following several tutorials webpage, but without any success .. each time after installing the build/make it says " no module named cv2 found .. " So the only working solution for me is using this ' pip install opencv-python ' )

Could you let me know how to reach this version '4.0.0.21' please ?
Thanks for your work Skvark !

[waveform80]

@wipix sorry, that's my fault - I built the opencv-python packages on the RPi but I've been too swamped to finish 4.x recently. I'll try and get the builders working on this next week but if you can't wait that long you'll just have to build it from source for now.

[wipix]

Hi Waveform80 , thank your for your response. Ok no problem , happy to hear that it's coming soon ! I'll wait ;) . Thanks for your hard work !

[ra-jamieson]

Hi,
Is there any rough ETA on releasing 4.01 with the fix to this drawKeypoints issue?
Like a week, a month, six months?
Thanks for any guidance.

[woctezuma]

Just in case someone who needs v4.0.1 on Windows stumbles here and cannot wait for the fix, you can download a .whl file from this repository and install it locally with pip. It is less handy than a PyPI install, but that might help in the meantime.

[skvark]

You can build OpenCV yourself if you need 4.0.1 right now or downgrade opencv-python to 3.4.5. I have been busy lately, but I'll have a look at the macOS Travis environments again during this week. I cannot give any estimates about the release date.