Crypto Smart Camera: Basic Motion

motion.py

import imutils

def motion(current_frame=None, previous_frame=None, avg=None, min_area=2000):
    motion = False
    
    gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
    gray = cv2.GaussianBlur(gray, (21, 21), 0)

    # if the average frame is None, initialize it
    if avg is None:
        log.info("Initialising average frame")
        avg = gray.copy().astype("float")
        raw_capture.truncate(0)
        continue

    # accumulate the weighted average between the current frame and
    # previous frames, then compute the difference between the current
    # frame and running average
    cv2.accumulateWeighted(gray, avg, 0.5)
    frame_delta = cv2.absdiff(gray, cv2.convertScaleAbs(avg))

    # threshold the delta image, dilate the thresholded image to fill
    # in holes, then find contours on thresholded image
    thresh = cv2.threshold(frame_delta, args.delta_threshold, 255, cv2.THRESH_BINARY)[1]
    thresh = cv2.dilate(thresh, None, iterations=2)
    (contours, _) = cv2.findContours(thresh.copy(), cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)

    for c in contours:
        # if the contour is too small, ignore it
        if cv2.contourArea(c) < min_area:
            continue

        motion = True
        log.info("Motion detected")

    return motion

Inspired by this post on pyimagesearch.com