Takt-Bilder auf einem Linux-Rechner (z.B. raspian) mit einem Python-Script mit einem Digital-Fotoapparat aufnehmen, Zeitraffer-Film daraus machen

(Still images captured under linux using python gphoto, made a movy out of the images)

• Installation der notwendigen Pakete, hier unter ubuntu:
  apt-get install libgphoto2 libgphoto2-dev gphoto2 digikam python-pip python-dev
• Mit dem Python Installer pip gphoto2 installieren:
  pip install gphoto2
• Bild(er) aufnehmen:
  python capture-image.py
  Das python-file capture-image.py liegt zusammen mit anderen examples im Verzeichnis /usr/local/share/python-gphoto2/examples/
  capture-image.py:

  #!/usr/bin/env python
  
  # python-gphoto2 - Python interface to libgphoto2
  # http://github.com/jim-easterbrook/python-gphoto2
  # Copyright (C) 2015  Jim Easterbrook  jim@jim-easterbrook.me.uk
  #
  # This program is free software: you can redistribute it and/or modify
  # it under the terms of the GNU General Public License as published by
  # the Free Software Foundation, either version 3 of the License, or
  # (at your option) any later version.
  #
  # This program is distributed in the hope that it will be useful,
  # but WITHOUT ANY WARRANTY; without even the implied warranty of
  # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  # GNU General Public License for more details.
  #
  # You should have received a copy of the GNU General Public License
  # along with this program.  If not, see .
  
  from __future__ import print_function
  
  import logging
  import os
  import subprocess
  import sys
  
  import gphoto2 as gp
  
  def main():
      logging.basicConfig(
          format='%(levelname)s: %(name)s: %(message)s', level=logging.WARNING)
      gp.check_result(gp.use_python_logging())
      context = gp.gp_context_new()
      camera = gp.check_result(gp.gp_camera_new())
      gp.check_result(gp.gp_camera_init(camera, context))
      print('Capturing image')
      file_path = gp.check_result(gp.gp_camera_capture(
          camera, gp.GP_CAPTURE_IMAGE, context))
      print('Camera file path: {0}/{1}'.format(file_path.folder, file_path.name))
      target = os.path.join('/tmp', file_path.name)
      print('Copying image to', target)
      camera_file = gp.check_result(gp.gp_camera_file_get(
              camera, file_path.folder, file_path.name,
              gp.GP_FILE_TYPE_NORMAL, context))
      gp.check_result(gp.gp_file_save(camera_file, target))
      subprocess.call(['xdg-open', target])
      gp.check_result(gp.gp_camera_exit(camera, context))
      return 0
  
  if __name__ == "__main__":
      sys.exit(main())
      

• Aus den vorliegenden jpgs (die von 'python capture-image.py' ge-captured wurden) einen kleinen mpeg4-Film erzeugen:
  avconv -i *JPG -b:v 1000k mov.mp4

#!/usr/bin/env python import cv2 import sys cascPath = sys.argv[1] faceCascade = cv2.CascadeClassifier(cascPath) video_capture = cv2.VideoCapture(0) while True: # Capture frame-by-frame ret, frame = video_capture.read() gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY) faces = faceCascade.detectMultiScale( gray, scaleFactor=1.1, minNeighbors=5, minSize=(30, 30), flags=cv2.cv.CV_HAAR_SCALE_IMAGE ) # Draw a rectangle around the faces for (x, y, w, h) in faces: cv2.rectangle(frame, (x, y), (x+w, y+h), (0, 255, 0), 2) # Display the resulting frame cv2.imshow('Video', frame) if cv2.waitKey(1) & 0xFF == ord('q'): break # When everything is done, release the capture video_capture.release() cv2.destroyAllWindows()

Hier noch: Standbild einer webcam mit python und opencv als File abspeichern import cv2 # Camera 0 is the integrated web cam on my netbook camera_port = 0 #Number of frames to throw away while the camera adjusts to light levels ramp_frames = 30 # Now we can initialize the camera capture object with the cv2.VideoCapture class. # All it needs is the index to a camera port. camera = cv2.VideoCapture(camera_port) # Captures a single image from the camera and returns it in PIL format def get_image(): # read is the easiest way to get a full image out of a VideoCapture object. retval, im = camera.read() return im # Ramp the camera - these frames will be discarded and are only used to allow v4l2 # to adjust light levels, if necessary for i in xrange(ramp_frames): temp = get_image() print("Taking image...") # Take the actual image we want to keep camera_capture = get_image() file = "/home/codeplasma/test_image.png" # A nice feature of the imwrite method is that it will automatically choose the # correct format based on the file extension you provide. Convenient! cv2.imwrite(file, camera_capture) # You'll want to release the camera, otherwise you won't be able to create a new # capture object until your script exits del(camera)