Reading, Displaying and Saving Images

# Typical imports
import cv2
import numpy as np
import matplotlib.pyplot as plt
import matplotlib
# Tells notebook to render figures in-page.
%matplotlib inline  
from IPython.display import Image

# Display Images Directly in the Browser

# Read Images using OpenCV
retval = cv2.imread(filename[, flags])

# Print the size of image.
print('Image size is ', bw_img.shape)

# Print data-type of image.
print('Data type of image is ', bw_img.dtype)

# Display the image.

# Set color map to gray scale for proper rendering.
plt.imshow(bw_img, cmap = 'gray');

# Save BGR file
cv2.imwrite(filename, img[, params])

Note: To avoid specifying a specific color map each time you call imshow() you can include the line below at the top of your notebook where the import statements are located which will set the color map globally.

matplotlib.rc('image', cmap = 'gray')

### Read and display an image
image = cv2.imread('Apollo-8-Launch.jpg')
plt.figure(figsize = [10, 10])
plt.title('Apollo-8-Launch.jpg', fontsize = 16);

# Save the image to the file system.
# The file format is determined by the file extension.
cv2.imwrite('Apollo-8-Launch.png', image)