This little program runs with python 3.5 using OpenCV 3.0 and compares image frames from an AVI file, displaying the difference image in a window. The differences are just scaled to fit, but you can come up with all kinds of variations on this.
import numpy as np
import cv2
# Capture video from file
cap=cv2.VideoCapture('/data/Code/Python/AAT/sim_imagery.avi')
old_frame = None
while True:
ret, frame = cap.read()
if ret == True:
gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
if old_frame is not None:
diff_frame = gray - old_frame
diff_frame -= diff_frame.min()
disp_frame = np.uint8(255.0*diff_frame/float(diff_frame.max()))
cv2.imshow('diff_frame',disp_frame)
old_frame = gray
if cv2.waitKey(30) & 0xFF == ord('q'):
break
else:
print('ERROR!')
break
cap.release()
cv2.destroyAllWindows()
Code:
import numpy as np
import cv2
cap = cv2.VideoCapture('/Users/nimya/Desktop/people-walking2.mp4')
ret, current_frame = cap.read()
fgbg = cv2.createBackgroundSubtractorMOG2()
previous_frame = current_frame
def framediff(current_frame_gray,previous_frame_gray):
frame_diff = cv2.absdiff(current_frame_gray,previous_frame_gray)
cv2.imshow('frame diff ',frame_diff)
return frame_diff
while(cap.isOpened()):
current_frame_gray = cv2.cvtColor(current_frame, cv2.COLOR_BGR2GRAY)
previous_frame_gray = cv2.cvtColor(previous_frame, cv2.COLOR_BGR2GRAY)
frame_diff=framediff(current_frame_gray,previous_frame_gray)
if cv2.waitKey(1) & 0xFF == ord('q'):
break
previous_frame = current_frame.copy()
ret, current_frame = cap.read()
cap.release()
cv2.destroyAllWindows()
Asked: 2018-06-22 02:48:14 -0600
Seen: 13,186 times
Last updated: Feb 27 '20
@Nimya, can you try to read over your question again, and improve it ? it's all too broad. movement of what ? compare ?
what are you trying to achieve ? what is the purpose ?
try do do some research on your own, like looking up optical flow.
I want to compare two frames in a video
sorry, too broad.
step 1:read two fames into two mats step 2:compare them