Mastering OpenCV 4 with Python

Chapter 3

1. The second element of the list is the first argument to the script, which is sys.argv[1].
2. The code is as follows:

parser = argparse.ArgumentParser()parser.add_argument("first_number", help="first number to be added", type=int)

3. The code to save the image is as follows:

cv2.imwrite("image.png", img)

4. The capture object is created as follows:

capture = cv2.VideoCapture(0)

5. The capture object is created as follows:

capture = cv2.VideoCapture(0)print("CV_CAP_PROP_FRAME_WIDTH: '{}'".format(capture.get(cv2.CAP_PROP_FRAME_WIDTH)))

6. The code to read the image is as follows:

image = cv2.imread("logo.png")cv2.imwrite("logo_copy.png", gray_image)

7. The script is written as follows:

"""Example to introduce how to read a video file backwards ...