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opencv--opencv/samples/python/background_subtractor_mask.py
T
2026-07-13 12:06:04 +08:00

69 lines
2.1 KiB
Python

'''
Showcases the use of background subtraction from a live video feed,
aswell as pass through of a known foreground parameter
'''
# Python 2/3 compatibility
from __future__ import print_function
import numpy as np
import cv2 as cv
def main():
cap = cv.VideoCapture(0)
if not cap.isOpened:
print("Capture source avaialable.")
exit()
# Create background subtractor
mog2_bg_subtractor = cv.createBackgroundSubtractorMOG2(history=300, varThreshold=50, detectShadows=False)
knn_bg_subtractor = cv.createBackgroundSubtractorKNN(history=300, detectShadows=False)
frame_count = 0
# Allows for a frame buffer for the mask to learn pre known foreground
show_count = 10
while True:
ret, frame = cap.read()
if not ret:
break
x = 100 + (frame_count % 10) * 3
frame = cv.resize(frame, (640, 480))
aKnownForegroundMask = np.zeros(frame.shape[:2], dtype=np.uint8)
# Allow for models to "settle"/learn
if frame_count > show_count:
cv.rectangle(aKnownForegroundMask, (x,200), (x+50,300), 255, -1)
cv.rectangle(aKnownForegroundMask, (540,180), (640,480), 255, -1)
#MOG2 Subtraction
mog2_with_mask = mog2_bg_subtractor.apply(frame,knownForegroundMask=aKnownForegroundMask)
mog2_without_mask = mog2_bg_subtractor.apply(frame)
#KNN Subtraction
knn_with_mask = knn_bg_subtractor.apply(frame,knownForegroundMask=aKnownForegroundMask)
knn_without_mask = knn_bg_subtractor.apply(frame)
# Display the 3 parameter apply and the 4 parameter apply for both subtractors
cv.imshow("MOG2 With a Foreground Mask", mog2_with_mask)
cv.imshow("MOG2 Without a Foreground Mask", mog2_without_mask)
cv.imshow("KNN With a Foreground Mask", knn_with_mask)
cv.imshow("KNN Without a Foreground Mask", knn_without_mask)
key = cv.waitKey(30)
if key == 27: # ESC
break
frame_count += 1
cap.release()
cv.destroyAllWindows()
if __name__ == '__main__':
print(__doc__)
main()
cv.destroyAllWindows()