opencv-python: Problem with cv2.drawKeypoints in version 4.0.0.21

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 https://github.com/opencv/opencv/issues/10250

About this issue

Original URL
State: closed
Created 5 years ago
Comments: 20 (5 by maintainers)

Most upvoted comments

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()

+14

woctezuma on Feb 5, 2019

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.

skvark on Jan 25, 2019

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

skvark on Feb 5, 2019

Below code worked for me after modifying drawKeypoints as suggested by @woctezuma Thanks 👍

import numpy as np
import cv2
from matplotlib import pyplot as plt

img = cv2.imread('/Images/object3.jpg',0)

# Initiate FAST object with default values
fast = cv2.FastFeatureDetector_create(threshold=25)

# find and draw the keypoints
kp = fast.detect(img, None)

# Print all default params
print ("Threshold: ", fast.getThreshold())
print ("NonmaxSuppression: ", fast.getNonmaxSuppression())
print ("Neighborhood: ", fast.getType())
print ("Total Keypoints with NonmaxSuppression: ", len(kp))

img2 = img.copy()
for marker in kp:
	img2 = cv2.drawMarker(img2, tuple(int(i) for i in marker.pt), color=(0, 255, 0))

cv2.imshow("FAST TRUE", img2)
cv2.imwrite('/Output/fast_true.png',img2)

# Disable nonmaxSuppression
fast.setNonmaxSuppression(0)
kp = fast.detect(img,None)
print ("Total Keypoints without NonmaxSuppression: ", len(kp))

img3 = img.copy()
for marker in kp:
	img3 = cv2.drawMarker(img3, tuple(int(i) for i in marker.pt), color=(0, 255, 0))

cv2.imshow("FAST False", img3)

if cv2.waitKey(0) & 0xFF == ord('q'):
    cv2.imwrite('/Output/fast_false.png',img3)
    cv2.destroyAllWindows()

joshlynsathish on Mar 20, 2019

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.

ra-jamieson on Mar 6, 2019

@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.

waveform80 on Feb 9, 2019

Do you know when 4.0.1 might be released? Thanks

Stephanehk on Feb 8, 2019