OpenCV & Python - Image too big to display

The other answers perform a fixed (width, height) resize. If you wanted to resize to a specific size while maintaining aspect ratio, use this

def ResizeWithAspectRatio(image, width=None, height=None, inter=cv2.INTER_AREA):
    dim = None
    (h, w) = image.shape[:2]

    if width is None and height is None:
        return image
    if width is None:
        r = height / float(h)
        dim = (int(w * r), height)
    else:
        r = width / float(w)
        dim = (width, int(h * r))

    return cv2.resize(image, dim, interpolation=inter)

Example

image = cv2.imread('img.png')
resize = ResizeWithAspectRatio(image, width=1280) # Resize by width OR
# resize = ResizeWithAspectRatio(image, height=1280) # Resize by height 

cv2.imshow('resize', resize)
cv2.waitKey()

Although I was expecting an automatic solution (fitting to the screen automatically), resizing solves the problem as well.

import cv2
cv2.namedWindow("output", cv2.WINDOW_NORMAL)    # Create window with freedom of dimensions
im = cv2.imread("earth.jpg")                    # Read image
imS = cv2.resize(im, (960, 540))                # Resize image
cv2.imshow("output", imS)                       # Show image
cv2.waitKey(0)                                  # Display the image infinitely until any keypress