Trouble with " cv2.imshow ()" function
imshow should be followed by waitKey function which displays the image for specified milliseconds. Otherwise, it won’t display the image. For example, waitKey(0) will display the window infinitely until any keypress (it is suitable for image display). waitKey(25) will display a frame for 25 ms, after which display will be automatically closed. (If you put it in a loop to read videos, it will display the video frame-by-frame). Here's a working example:
import cv2
img = cv2.imread('a.jpg')
cv2.imshow('FRAME', img)
cv2.waitKey(0)
cv2.destroyAllWindows()
Kushagra
Updated on June 07, 2022Comments
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Kushagra almost 2 years
I installed openCV and numpy libraries in python 2.7.
I've tested them using commands
import cv2
andimport numpy
and it compiled.But when I use the
cv2.imshow('frame', ----)
function it displays a window but not displaying the image. And it's showing " frame is Not Responding".So, I tried with matplotlib functions for displaying image and it worked.
I inserted
cv2.imshow
function in the 2nd case and it worked.Versions [Python-2.7.10, OpenCV-2.4.11]
Below is the code,
Case 1: Not Working,displaying window but not image (showing FRAME IS NOT RESPONDING)
import cv2 import numpy img = cv2.imread('a.jpg') cv2.imshow('FRAME',img)
Case 2: Working
import matplotlib.pyplot as plt import matplotlib.image as mpimg import numpy as np import cv2 img = mpimg.imread('a.jpg') img2 = cv2.imread('b.jpg') cv2.imshow('FRAME',img2) plt.imshow(img) plt.show()
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ImportanceOfBeingErnest over 7 yearsThis does not solve the question since the problem arises when showing the image, and that is independent of reading it in.