Save multiple images with OpenCV and Python

Question

I\'m using OpenCV and Python to take images. However currently I can only take one picture at a time. I would like to have OpenCV to take multiple pictures. This is my current c

Answer 1

A minimal example of what you'd like to do, based on the c++ binded interface.

import cv2

cpt = 0
maxFrames = 5 # if you want 5 frames only.

try:
    vidStream = cv2.VideoCapture(0) # index of your camera
except:
    print "problem opening input stream"
    sys.exit(1)

while cpt < maxFrames:
    ret, frame = vidStream.read() # read frame and return code.
    if not ret: # if return code is bad, abort.
        sys.exit(0)
    cv2.imshow("test window", frame) # show image in window
    cv2.imwrite("image%04i.jpg" %cpt, frame)
    cpt += 1

A full example of script, able to read from a camera index, or a file. Includes some failsafes and some information about read device.

usage: record.py [source] [target folder]

#!/usr/bin/env python
import cv2
import sys
import os

cpt = 0
maxFrames = 30

try:
    targetDir = sys.argv[2]
except:
    targetDir = "" # if no argument, then use current directory

try: # read input. eval if to transform video index to int
    vidStream = cv2.VideoCapture(eval(sys.argv[1]))
except:
    print "problem opening input stream"
    sys.exit(1)
if not vidStream.isOpened():
    print "capture stream not open"
    sys.exit(1)

# informations in case the input is a video file.
nFrames = vidStream.get(cv2.cv.CV_CAP_PROP_FRAME_COUNT)
print "frame number: %s" %nFrames
fps = vidStream.get(cv2.cv.CV_CAP_PROP_FPS)
print "FPS value: %s" %fps

# note that we could use frame number here, or "while 1"
# so we could read from a live written file or capture devide.
while cpt < maxFrames:
    ret, frame = vidStream.read() # read frame and return code.
    if not ret:
        print "end of stream"
        sys.exit(0)
    cv2.imshow("test window", frame) # show image in window
    cv2.imwrite(os.path.join(targetDir, "image_%04i.jpg" %cpt), frame)
    cpt += 1
    keyPressed = cv2.waitKey(1) # time to wait between frames
    if keyPressed != -1: # if user pressed a key, stop recording.
        sys.exit(0)