Motion detection program for snapping of images

Question

I'm doing a motion detection program where it snaps an image when it detects movement and snaps an image of the person's face if in view while this is all recorded and sends it all to Dropbox.

It's moving very slowly and lagging like crazy, showing 1 frame in like a minute. Is there a way to optimize it?

I'm using a Raspberry Pi to code all this, and a webcam.

import sys
sys.path.append('/usr/local/lib/python3.4/site-packages')
import numpy as np
import cv2
import imutils
from imutils import contours
import datetime
import time
import dropbox


#Function fo Drawing rect and changing text to REC
def draw_rect_movement(c):
    #Draw Rectangle around found contour object
    (x, y, w, h) = cv2.boundingRect(c)
    cv2.rectangle(frame, (x,y), (x+w,y+h), (0,255,0), 2)
    text = "REC"
    return c    

def saveNupload(roi_color):
    #writing image of face as png in the file
    timestring = time.strftime("%Y_%m_%d_%H_%M_%S")
    face_timestr = 'face_' + timestring + '.png'
    cv2.imwrite(face_timestr, roi_color)

    #Opening for [r]eading as [b]inary
    FaceFile = open(face_timestr, mode = "rb")
    #Reads the number of bytes of the video
    data = FaceFile.read()

    #Setting the save location with file name
    SavetoLocation = '/FYP_Face_Save/'+ face_timestr
    SaveToLocation = str(SavetoLocation)

    dbx.files_upload(data, SaveToLocation)
    #Close for reading and binary
    FaceFile.close()    

dbx = dropbox.Dropbox('Access Token')
dbx.users_get_current_account()

#cap = cv2.VideoCapture("/home/pi/Desktop/Proj/VideoTestSample.mp4")
cap = cv2.VideoCapture(1)

#Creating froeground and removing Background
fgbg = cv2.createBackgroundSubtractorMOG2(detectShadows=False)

#Set format
fourcc = cv2.VideoWriter_fourcc(*'XVID')
#Get Datetime
timestr = time.strftime("%Y_%m_%d_%H_%M_%S")
#Creating name of folder
timestr = timestr + '.avi'
#Setting Name, Format, FPS, FrameSize
out = cv2.VideoWriter(timestr,fourcc, 10.0, (640, 480))

#setting casacade for use
face_cascade = cv2.CascadeClassifier('haarcascade_frontalface_default.xml')

#setting criteria for  termination
term_crit = ( cv2.TERM_CRITERIA_EPS | cv2.TERM_CRITERIA_COUNT, 10, 1 )
#As long as the VideoCapture is open loop to show the frames
while (cap.isOpened()):
    #capture frame-by-frame
    (grabbed, frame) = cap.read()
    text = " "

    if not grabbed:
        break

    #Convert frame to Black white and gray
    gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)

    #placing Cascade detection
    faces = face_cascade.detectMultiScale(gray, 1.2,)

    #Drawing around the detected "face"
    for (x, y, w, h) in faces:
        cv2.rectangle(frame, (x -20,y-20), (x + w + 20, y + h + 20), (255,0,0), 2)
        roi_color = frame[y-20:y + h + 20, x -20:x + w + 20]

        saveNupload(roi_color = roi_color)

    #Apply the Background SubtractionMOG2
    fgmask = fgbg.apply(gray)
    #Erode away the boundaries of the foreground object
    thresh = cv2.erode(fgmask, None, iterations=2)

    #Set detect as none
    detect = None

    #FindContours returns a list of the outlines of the white shapes in the mask (and a heirarchy that we shall ignore)   
    (_,cnts,hierarchy) = cv2.findContours(thresh.copy(), cv2.RETR_TREE, cv2.CHAIN_APPROX_SIMPLE)

    #Draw the DateTime on the bottom left hand corner
    cv2.putText(frame, datetime.datetime.now().strftime("%A %d %B %Y %I:%M:%S%p"),
                (10, frame.shape[0] - 10), cv2.FONT_HERSHEY_SIMPLEX, 0.35,(0,0,255), 1)    

    #detect is object found or not found
    detect = (_,cnts,hierarchy)

    #if object found is detected run these codes
    if detect == (_,cnts,hierarchy):

        #if area of object is lower than 300 ignore it 
        for (i,c) in enumerate(cnts):
            if cv2.contourArea(c) < 1100:
                print("ignore small contours", cv2.contourArea(c))
                continue

            #Uncomment this function call to display motion detected
            ###draw_rect_movement(c = c)

            #Temporary code
            text = "Movement Detected ... Snapping"

            #Capture image
            timestring = time.strftime("%Y_%m_%d_%H_%M_%S")
            image_timestr = 'image_' + timestring + '.png'
            cv2.imwrite(image_timestr, frame)

            #Opening for [r]eading as [b]inary
            ImageFile = open(image_timestr, mode = "rb")
            #Reads the number of bytes of the video
            data = ImageFile.read()

            #Setting the save location with file name
            SavetoLocation = '/FYP_Image_Save/'+ image_timestr
            SaveToLocation = str(SavetoLocation)

            dbx.files_upload(data, SaveToLocation)
            #Close for reading and binary
            ImageFile.close()            

            detect= None 

            if detect != (_,cnts,hierarchy):
                continue

    elif  detect != (_,cnts,hierarchy):
        print("Not Snaping")

    else:
        continue

    #Draw the text at top right hand corner
    cv2.putText(frame, "{}". format(text), (10,20),
                cv2.FONT_HERSHEY_SIMPLEX, 0.5, (0, 0, 255), 2)

    #Write which window into video in this case Frame
    out.write(frame) 
    #Display the following windows
    cv2.imshow('frame',frame)
    cv2.imshow('gray', gray)
    cv2.imshow('fgmask', fgmask)

    #if q is pressed break loop
    if cv2.waitKey(1) & 0xFF == ord('q'):
        break

#Stop recording 
out.release()
#Kill all windows
cap.release()
cv2.destroyAllWindows()

#Opening for [r]eading as [b]inary
VideoFile = open(timestr, mode = "rb")
#Reads the number of bytes of the video
data = VideoFile.read()

#Setting the save location with file name
SavetoLocation = '/FYP_Video_Save/'+timestr
SaveToLocation = str(SavetoLocation)

#Upload the file
print("Sending to Dropbox")
dbx.files_upload(data, SaveToLocation)
#Close for reading and binary
VideoFile.close()

Answer 1

sys.path.append('/usr/local/lib/python3.4/site-packages')

Recommend you use a proper package manager to install numpy and friends, such as conda, or pip virtualenv.

(x, y, w, h) = cv2.boundingRect(c)

No need for ( extra parens ) on the tuple unpack. Recommend you run $ flake8, and heed its advice, preferring identifiers like e.g. save_and_upload or face_file.

SaveToLocation = str(SavetoLocation)

You already had a str, so the function call does nothing.

#Creating froeground

Typo.

while (cap.isOpened()):

No need for ( extra parens ). Same remark for the grabbed, frame tuple unpack.

            detect= None 
            if detect != (_,cnts,hierarchy):
                continue

An unconditional continue would suffice.

The while loop in __main__ is far too long, and should be packaged up in one or more helper functions.

You didn't post any profiling / timing data, but I assume you spend the bulk of elapsed time here:

    faces = face_cascade.detectMultiScale(gray, 1.2)

Following the advice of BKSpurgeon and Aleksandar, it would make sense to guard this with some cheap check for changed pixels, perhaps using cv2.absdiff(), before requesting the full-blown face finder. Histograms certainly are a good way of summarizing images and noticing gross differences.