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@chuanenlin
Created April 12, 2019 02:43
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import cv2 as cv
import numpy as np
# The video feed is read in as a VideoCapture object
# cap = cv.VideoCapture("shibuya.mp4")
# ret = a boolean return value from getting the frame, first_frame = the first frame in the entire video sequence
# ret, first_frame = cap.read()
# Converts frame to grayscale because we only need the luminance channel for detecting edges - less computationally expensive
prev_gray = cv.cvtColor(first_frame, cv.COLOR_BGR2GRAY)
# while(cap.isOpened()):
# ret = a boolean return value from getting the frame, frame = the current frame being projected in the video
# ret, frame = cap.read()
# Opens a new window and displays the input frame
# cv.imshow("input", frame)
# Converts each frame to grayscale - we previously only converted the first frame to grayscale
gray = cv.cvtColor(frame, cv.COLOR_BGR2GRAY)
# Visualizes checkpoint 2
cv.imshow("grayscale", gray)
# Updates previous frame
prev_gray = gray
# Frames are read by intervals of 1 millisecond. The programs breaks out of the while loop when the user presses the 'q' key
# if cv.waitKey(1) & 0xFF == ord('q'):
# break
# The following frees up resources and closes all windows
# cap.release()
# cv.destroyAllWindows()
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