pyopencv_motion5_fullcode.py

import cv2
import numpy as np
from PIL import ImageGrab

def motion_detector_gist():

  previous_frame = None

  while True:

    # 1. Load image; convert to RGB
    img_brg = np.array(ImageGrab.grab())
    img_rgb = cv2.cvtColor(src=img_brg, code=cv2.COLOR_BGR2RGB)


    # 2. Prepare image; grayscale and blur
    prepared_frame = cv2.cvtColor(img_rgb, cv2.COLOR_BGR2GRAY)
    prepared_frame = cv2.GaussianBlur(src=prepared_frame, ksize=(5, 5), sigmaX=0)

    # 2. Calculate the difference
    if (previous_frame is None):
      # First frame; there is no previous one yet
      previous_frame = prepared_frame
      continue

    # 3. calculate difference and update previous frame
    diff_frame = cv2.absdiff(src1=previous_frame, src2=prepared_frame)
    previous_frame = prepared_frame

    # 4. Dilute the image a bit to make differences more seeable; more suitable for contour detection
    kernel = np.ones((5, 5))
    diff_frame = cv2.dilate(diff_frame, kernel, 1)

    # 5. Only take different areas that are different enough (>20 / 255)
    thresh_frame = cv2.threshold(src=diff_frame, thresh=20, maxval=255, type=cv2.THRESH_BINARY)[1]

    # 6. Find and optionally draw contours
    contours, _ = cv2.findContours(image=thresh_frame, mode=cv2.RETR_EXTERNAL, method=cv2.CHAIN_APPROX_SIMPLE)
    # Comment below to stop drawing contours
    cv2.drawContours(image=img_rgb, contours=contours, contourIdx=-1, color=(0, 255, 0), thickness=2, lineType=cv2.LINE_AA)
    # Uncomment 6 lines below to stop drawing rectangles
    # for contour in contours:
    #   if cv2.contourArea(contour) < 50:
    #     # too small: skip!
    #       continue
    #   (x, y, w, h) = cv2.boundingRect(contour)
    #   cv2.rectangle(img=img_rgb, pt1=(x, y), pt2=(x + w, y + h), color=(0, 255, 0), thickness=2)

    cv2.imshow('Motion detector', img_rgb)

    if (cv2.waitKey(30) == 27):
      # out.release()
      break

  # Cleanup
  cv2.destroyAllWindows()

if __name__ == "__main__":
  motion_detector_gist()

Can i get the full source code?

he roastedmonk. check out the full source code plus accompanying article here

he roastedmonk. check out the full source code plus accompanying article here

That's not the "full code", in fact, you will not be able to construct a working example from that document just fragments of how bits of the idea work - which limits its usefulness to just reference. So I would remove the term full-code if you're not going to post it.

Yeah i constructed needed code. So thank you. Regards,Subramaniam 

@DrJaymz
Just call the function in this gist with

if (name == "main"):
motion_detector_gist()

Nice function! The article explains it fully, and the code is complete bar being called.
Thanks

Thank you for good example.
But could you be so kind to show the real working code, not a snippet. I tried to show my kid this example and it took 2 hours to get it working.

import cv2
import numpy as np
from PIL import ImageGrab

def motion_detector_gist():
......
motion_detector_gist()

import cv2 import numpy as np from PIL import ImageGrab

Thank you @batona!

Please notice that this piece of code is repeated twice, you can safely delete one of the if

Thank you @lorenzua02! I've fixed it!

Thanks for the example. FYI, your article still has frame_count and the if statement where prepared_frame can never be reached.