How can one display an image using cv2 in Python
PythonOpencvMatplotlibPython Problem Overview
I've been working with code to display frames from a movie. The bare bones of the code is as follows:
import cv2
import matplotlib.pyplot as plt
# Read single frame avi
cap = cv2.VideoCapture('singleFrame.avi')
rval, frame = cap.read()
# Attempt to display using cv2 (doesn't work)
cv2.namedWindow("Input")
cv2.imshow("Input", frame)
#Display image using matplotlib (Works)
b,g,r = cv2.split(frame)
frame_rgb = cv2.merge((r,g,b))
plt.imshow(frame_rgb)
plt.title('Matplotlib') #Give this plot a title,
#so I know it's from matplotlib and not cv2
plt.show()
Because I can display the image using matplotlib, I know that I'm successfully reading it in.
I don't understand why my creation of a window and attempt to show an image using cv2 doesn't work. No cv2 window ever appears. Oddly though, if I create a second cv2 window, the 'input' window appears, but it is only a blank/white window.
What am I missing here?
Python Solutions
Solution 1 - Python
As far as I can see, you are doing it almost good. There is one thing missing:
cv2.imshow('image',img)
cv2.waitKey(0)
So probably your window appears but is closed very very fast.
Solution 2 - Python
you can follow following code
import cv2
# read image
image = cv2.imread('path to your image')
# show the image, provide window name first
cv2.imshow('image window', image)
# add wait key. window waits until user presses a key
cv2.waitKey(0)
# and finally destroy/close all open windows
cv2.destroyAllWindows()
I think your job is done then
Solution 3 - Python
Since OpenCV reads images with BGR format, you'd convert it to RGB format before pass the image to pyplot
import cv2
import matplotlib.pyplot as plt
image = cv2.imread('YOUR_FILEPATH')
image = cv2.cvtColor(image, cv2.COLOR_BGR2RGB)
plt.imshow(image)
plt.show()
Solution 4 - Python
While using Jupyter Notebook this one might come in handy
import cv2
import matplotlib.pyplot as plt
# reading image
image = cv2.imread("IMAGE_PATH")
# displaying image
plt.imshow(image)
plt.show()