1# Copyright (c) 2012 The Chromium OS Authors. All rights reserved. 2# Use of this source code is governed by a BSD-style license that can be 3# found in the LICENSE file. 4 5import glob, os 6import numpy as np 7 8# Dimension padding/unpadding function for converting points matrices to 9# the OpenCV format (channel-based). 10def Pad(x): 11 return np.expand_dims(x, axis=0) 12 13 14def Unpad(x): 15 return np.squeeze(x) 16 17 18class Pod(object): 19 '''A POD (plain-old-data) object containing arbitrary fields.''' 20 def __init__(self, **args): 21 self.__dict__.update(args) 22 23 def __repr__(self): 24 '''Returns a representation of the object, including its properties.''' 25 return (self.__class__.__name__ + '(' + 26 ', '.join('%s=%s' % (k, v) for k, v in sorted(self.__dict__.items()) 27 if not k.startswith('_')) + ')') 28 29 30def find_camera(): 31 """ 32 Find a V4L camera device. 33 34 @return (device_name, device_index). If no camera is found, (None, None). 35 """ 36 cameras = [os.path.basename(camera) for camera in 37 glob.glob('/sys/bus/usb/drivers/uvcvideo/*/video4linux/video*')] 38 if not cameras: 39 return None, None 40 camera = cameras[0] 41 return camera, int(camera[5:]) 42