chore: import upstream snapshot with attribution

2026-07-13 12:06:04 +08:00
commit 86c9b1c39f
7743 changed files with 3316339 additions and 0 deletions
@@ -0,0 +1,68 @@
+
+'''
+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()