capture nearly every 1 second

capture.py

#!/usr/bin/python3
import numpy as np
import cv2
import datetime
from time import sleep

cap = cv2.VideoCapture(0)
cap.set(cv2.CAP_PROP_FRAME_WIDTH, 1920)
cap.set(cv2.CAP_PROP_FRAME_HEIGHT, 1080)

# 15fps: 1/15 = 0.066666667
one_sec = datetime.timedelta(microseconds=990000)
#one_sec = datetime.timedelta(seconds=1)
while(True):
    start = datetime.datetime.now()
    dt = start.strftime('%Y%m%d-%H%M%S')
    ms = '{0:03f}'.format(start.microsecond/1000)

    ret, frame = cap.read()
    cv2.imwrite("img/" + dt + "-" + ms + ".jpg", frame)

    while(True):
        end = datetime.datetime.now()
        if (end - start) > one_sec:
            break
        sleep(0.01)

# sleep is not so much accurate
#sleep(1.0 - (start.microsecond - end.microsecond) / 1000000.0) 

cap.release()
cv2.destroyAllWindows()

diff.py

# TODO shebang and exec flag
import cv2
import glob
import numpy as np
import os
import sys

"""calc diff compared with next jpg.
usage: python diff.py PATH
"""

path = sys.argv[-1]
files = sorted(glob.glob(path + '*.jpg'))
count = 0
minimum = 1920 * 1080 * 255
print(path + 'mask.png')
mask = cv2.imread('mask.png', cv2.IMREAD_GRAYSCALE)
curr = cv2.imread(files[-1], cv2.IMREAD_GRAYSCALE) * mask

# TODO if-condition 3600
group_num = 3600 / (len(files) - 3600)

print("path, diff value compared with prev img")
for f in files:
  prev = curr
  curr = cv2.imread(f, cv2.IMREAD_GRAYSCALE) * mask
  diff = cv2.absdiff(prev, curr)
  diff_sum = diff.sum()
  print(f + ', ' + str(diff_sum))
  if minimum > diff_sum:
    minimum = diff_sum
    path = f
  count = count + 1

  if count > group_num:
    dest = os.path.dirname(path) + "/../unused/" + os.path.basename(path)
    print(path + ", " + dest + ", was moved")
    os.rename(path, dest)
    minimum = 1920 * 1080 * 255
    count = 0