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Merge pull request #2 from twyszomirski/performance-improvments
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Improved performance when counting black pixels.
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@RobinDavid
RobinDavid authored Jan 5, 2018
2 parents 81663c1 + d1d20e5 commit 0279bb5
Showing 1 changed file with 5 additions and 10 deletions.
15 changes: 5 additions & 10 deletions MotionDetector.py
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Original file line number Diff line number Diff line change
Expand Up @@ -91,17 +91,12 @@ def processImage(self, frame):

def somethingHasMoved(self):
nb=0 #Will hold the number of black pixels

for x in range(self.height): #Iterate the hole image
for y in range(self.width):
if self.res[x,y] == 0.0: #If the pixel is black keep it
nb += 1
avg = (nb*100.0)/self.nb_pixels #Calculate the average of black pixel in the image

if avg > self.threshold:#If over the ceiling trigger the alarm
return True
min_threshold = (self.nb_pixels/100) * self.threshold #Number of pixels for current threshold
nb = self.nb_pixels - cv.CountNonZero(self.res)
if (nb) > min_threshold:
return True
else:
return False
return False

if __name__=="__main__":
detect = MotionDetectorInstantaneous(doRecord=True)
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1 comment on commit 0279bb5

@46382
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@46382 46382 commented on 0279bb5 Aug 2, 2021

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###i think below code is trying ta take a first frame as reference for all thats why it efffect when the camera is changing its position i want the reference frame as previous frame so how can i change***

import cv2 as cv
import numpy as np
from datetime import datetime
import time

class MotionDetectorInstantaneous():

def onChange(self, val):    # callback when the user change the detection threshold
    self.threshold = val

def __init__(self, threshold=8, doRecord=True, showWindows=True):
    self.writer = None
    self.font = None
    self.doRecord = doRecord  # Either or not record the moving object
    self.show = showWindows   # Either or not show the 2 windows
    self.frame = None

    self.capture = cv.VideoCapture(0)
    self.frame = self.capture.read()[1]  # Take a frame to init recorder
    if doRecord:
        self.initRecorder()
    
    self.frame1gray = cv.cvtColor(self.frame, cv.COLOR_BGR2GRAY).astype(np.uint8) #Convert to gray otherwise can't do threshold
    
    #Will hold the thresholded result
    self.res = np.zeros(self.frame.shape[1::-1]).astype(np.uint8)
    
    self.frame2gray = np.zeros(self.frame.shape[1::-1]).astype(np.uint8) #Gray frame at t
    
    self.width = self.frame.shape[0]
    self.height = self.frame.shape[1]
    self.nb_pixels = self.width * self.height
    self.threshold = threshold
    self.isRecording = False
    self.trigger_time = 0 #Hold timestamp of the last detection

    self.kernel = cv.getStructuringElement(cv.MORPH_RECT,(5,5))
    
    if showWindows:
        cv.namedWindow("Image")
        cv.createTrackbar("Detection treshold: ", "Image", self.threshold, 50, self.onChange)
    
def initRecorder(self): #Create the recorder
    codec = cv.VideoWriter_fourcc('M', 'J', 'P', 'G') #('W', 'M', 'V', '2')
    self.writer=cv.VideoWriter(datetime.now().strftime("%b-%d_%H_%M_%S")+".wmv", codec, 30, self.frame.shape[1::-1], 1)
    #FPS set to 5 because it seems to be the fps of my cam but should be ajusted to your needs ///IB2S change FPS 5 to 30
    self.font = cv.FONT_HERSHEY_SIMPLEX #Creates a font

def run(self):
    started = time.time()
    while True:
        
        curframe = self.capture.read()[1]
        instant = time.time() #Get timestamp o the frame
        
        self.processImage(curframe) #Process the image
        
        if not self.isRecording:
            if self.somethingHasMoved():
                self.trigger_time = instant #Update the trigger_time
                if instant > started +5:#Wait 5 second after the webcam start for luminosity adjusting etc..
                    print(datetime.now().strftime("%b %d, %H:%M:%S"), "Something is moving !")
                    if self.doRecord: #set isRecording=True only if we record a video
                        self.isRecording = True
        else:
            if instant >= self.trigger_time +10: #Record during 10 seconds
                print(datetime.now().strftime("%b %d, %H:%M:%S"), "Stop recording")
                self.isRecording = False
            else:
                cv.putText(curframe, datetime.now().strftime("%b %d, %H:%M:%S"), (25,30),self.font, 1, (255, 0, 0), 2, cv.LINE_AA) #Put date on the frame
                self.writer.write(curframe) #Write the frame
        
        if self.show:
            cv.imshow("Image", curframe)
            cv.imshow("Res", self.res)
            
        self.frame2gray = self.frame1gray.copy()
        c=cv.waitKey(1) % 0x100
        if c==27 or c == 10: #Break if user enters 'Esc'.
            break            

def processImage(self, frame):
    self.frame2gray = cv.cvtColor(frame, cv.COLOR_BGR2GRAY) #Convert to gray otherwise can't do threshold
    
    #Absdiff to get the difference between to the frames
    self.res = cv.absdiff(self.frame1gray, self.frame2gray)
    
    #Remove the noise and do the threshold
    self.res = cv.GaussianBlur(self.res, (21,21), 0) #Remove false positives
    self.res = cv.morphologyEx(self.res, cv.MORPH_OPEN, self.kernel)
    self.res = cv.morphologyEx(self.res, cv.MORPH_CLOSE, self.kernel)
    self.res = cv.threshold(self.res, 10, 255, cv.THRESH_BINARY_INV)[1]     # self.res = cv.threshold(self.res, 10, 255, cv.THRESH_BINARY_INV)[1]

def somethingHasMoved(self):
    nb=0 #Will hold the number of black pixels
    min_threshold = (self.nb_pixels/100) * self.threshold #Number of pixels for current threshold
    nb = self.nb_pixels - cv.countNonZero(self.res)
    if (nb) > min_threshold:
       return True
    else:
       return False

if name=="main":
detect = MotionDetectorInstantaneous(doRecord=True)
detect.run()

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