camera.py

import cv2


def capture(img_file):

    video = cv2.VideoCapture(1)

    while True:
        ret, im = video.read()
        p1 = (140, -1)
        p2 = (140 + 360, 480)
        cv2.rectangle(im, p1, p2, (255, 255, 255), thickness=2)

        cv2.imshow('Camera', im)
        key = cv2.waitKey(10)

        if key % 256 == 27:    # Esc key to stop
            break
        elif key % 256 == ord(' ') or \
                key % 256 == 141 or key % 256 == 10:    # Capture the image
            cv2.imwrite(img_file, im)
            cv2.imshow('Picture Captured', im)
        elif key == -1:  # normally -1 returned,so don't print it
            continue
        else:
            print 'You pressed %d (0x%x), LSB: %d (%s)' % (
                key, key, key % 256,
                repr(chr(key % 256)) if key % 256 < 128 else '?'
            )

    # When everything done, release the capture
    video.release()
    cv2.destroyAllWindows()

if __name__ == "__main__":

    import sys

    if len(sys.argv) > 1:
        capture('output/pics/%s.jpg' % sys.argv[1])
    else:
        exit(1)