OpenCV_4.2.0/opencv_contrib-4.2.0/modules/optflow/samples/motempl.py

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2024-07-25 16:47:56 +08:00
#!/usr/bin/env python
import numpy as np
import cv2 as cv
MHI_DURATION = 0.5
DEFAULT_THRESHOLD = 32
MAX_TIME_DELTA = 0.25
MIN_TIME_DELTA = 0.05
# (empty) trackbar callback
def nothing(dummy):
pass
def draw_motion_comp(vis, rect, angle, color):
x, y, w, h = rect
cv.rectangle(vis, (x, y), (x+w, y+h), (0, 255, 0))
r = min(w//2, h//2)
cx, cy = x+w//2, y+h//2
angle = angle*np.pi/180
cv.circle(vis, (cx, cy), r, color, 3)
cv.line(vis, (cx, cy), (int(cx+np.cos(angle)*r), int(cy+np.sin(angle)*r)), color, 3)
if __name__ == '__main__':
import sys
try:
video_src = sys.argv[1]
except:
video_src = 0
cv.namedWindow('motempl')
visuals = ['input', 'frame_diff', 'motion_hist', 'grad_orient']
cv.createTrackbar('visual', 'motempl', 2, len(visuals)-1, nothing)
cv.createTrackbar('threshold', 'motempl', DEFAULT_THRESHOLD, 255, nothing)
cam = cv.VideoCapture(video_src)
if not cam.isOpened():
print("could not open video_src " + str(video_src) + " !\n")
sys.exit(1)
ret, frame = cam.read()
if ret == False:
print("could not read from " + str(video_src) + " !\n")
sys.exit(1)
h, w = frame.shape[:2]
prev_frame = frame.copy()
motion_history = np.zeros((h, w), np.float32)
hsv = np.zeros((h, w, 3), np.uint8)
hsv[:,:,1] = 255
while True:
ret, frame = cam.read()
if ret == False:
break
frame_diff = cv.absdiff(frame, prev_frame)
gray_diff = cv.cvtColor(frame_diff, cv.COLOR_BGR2GRAY)
thrs = cv.getTrackbarPos('threshold', 'motempl')
ret, motion_mask = cv.threshold(gray_diff, thrs, 1, cv.THRESH_BINARY)
timestamp = cv.getTickCount() / cv.getTickFrequency()
cv.motempl.updateMotionHistory(motion_mask, motion_history, timestamp, MHI_DURATION)
mg_mask, mg_orient = cv.motempl.calcMotionGradient( motion_history, MAX_TIME_DELTA, MIN_TIME_DELTA, apertureSize=5 )
seg_mask, seg_bounds = cv.motempl.segmentMotion(motion_history, timestamp, MAX_TIME_DELTA)
visual_name = visuals[cv.getTrackbarPos('visual', 'motempl')]
if visual_name == 'input':
vis = frame.copy()
elif visual_name == 'frame_diff':
vis = frame_diff.copy()
elif visual_name == 'motion_hist':
vis = np.uint8(np.clip((motion_history-(timestamp-MHI_DURATION)) / MHI_DURATION, 0, 1)*255)
vis = cv.cvtColor(vis, cv.COLOR_GRAY2BGR)
elif visual_name == 'grad_orient':
hsv[:,:,0] = mg_orient/2
hsv[:,:,2] = mg_mask*255
vis = cv.cvtColor(hsv, cv.COLOR_HSV2BGR)
for i, rect in enumerate([(0, 0, w, h)] + list(seg_bounds)):
x, y, rw, rh = rect
area = rw*rh
if area < 64**2:
continue
silh_roi = motion_mask [y:y+rh,x:x+rw]
orient_roi = mg_orient [y:y+rh,x:x+rw]
mask_roi = mg_mask [y:y+rh,x:x+rw]
mhi_roi = motion_history[y:y+rh,x:x+rw]
if cv.norm(silh_roi, cv.NORM_L1) < area*0.05:
continue
angle = cv.motempl.calcGlobalOrientation(orient_roi, mask_roi, mhi_roi, timestamp, MHI_DURATION)
color = ((255, 0, 0), (0, 0, 255))[i == 0]
draw_motion_comp(vis, rect, angle, color)
cv.putText(vis, visual_name, (20, 20), cv.FONT_HERSHEY_PLAIN, 1.0, (200,0,0))
cv.imshow('motempl', vis)
prev_frame = frame.copy()
if 0xFF & cv.waitKey(5) == 27:
break
# cleanup the camera and close any open windows
cam.release()
cv.destroyAllWindows()