pycamera

Overview (08/12/2013)

This is a pre-alpha version a Python wrapper for the C++ Camera SDK developed by Natural Point for OptiTrack motion capture systems (http://www.naturalpoint.com/optitrack/products/camera-sdk/). Only the most basic functionality has been implemented so far.

The wrapper uses a programming language called Cython. You will need to have a version of Microsoft's Visual Studio with a C++ compiler installed compilation has only been tested with Visual Studio 2010 to date.

Compilation and Module Installation

1. Change to the directory containing all the files you downloaded (the one that contains camera.pxd, frame.pxd, etc.)

2. run python setup.py build_ext --inplace

3. OPTIONAL - Add the directory where you ran setup.py to your PYTHONPATH environment variable (to enable you to load the ycamera module without having to run the Python shell from that directory every time)

Example Usage

The sample code below creates a CameraList and gets a reference to the CameraManager. Calling get_camera_list() initializes the CameraList. It then gets a camera, sets the video type and framerate. Once the camera is started, get_latest_frame() gets the most recent frame. A Numpy array is used to store the image and matplotlib functions imshow() and show() are used to visualize the image.

import pycamera as p  
import numpy as np  
import ctypes  
from pylab import imshow, show

IMG_WIDTH = 832 # Use S250e camera
IMG_HEIGHT = 832 

pcl = p.PyCameraList()  
cm = p.CameraManager()  
cm.get_camera_list()  
cam = cm.get_camera_by_serial(<sn>)  
cam.set_video_type(p.VideoMode.VM_MJPEG_MODE)  
cam.set_framerate(250) #Framerate must be supported by camera hardware  
cam.start()  
f = cam.get_latest_frame()  
my_buffer = np.ones((IMG_WIDTH, IMG_HEIGHT), dtype=ctypes.c_ubyte)  
f.rasterize(IMG_WIDTH, IMG_HEIGHT, 0, 8, my_buffer)  
imshow(my_buffer)  
show()

The order of operations in the above code is very important. Alternative approaches (such as instantiating the CameraManager before the CameraList) have crashed the Python runtime (likely due to a null pointer error).