Python Imath.Channel() Examples

The following are 3 code examples of Imath.Channel(). You can vote up the ones you like or vote down the ones you don't like, and go to the original project or source file by following the links above each example. You may also want to check out all available functions/classes of the module Imath , or try the search function

Example #1

Source File: img_io.py From hdrcnn with BSD 3-Clause "New" or "Revised" License

7 votes

def writeEXR(img, file):
    try:
        img = np.squeeze(img)
        sz = img.shape
        header = OpenEXR.Header(sz[1], sz[0])
        half_chan = Imath.Channel(Imath.PixelType(Imath.PixelType.HALF))
        header['channels'] = dict([(c, half_chan) for c in "RGB"])
        out = OpenEXR.OutputFile(file, header)
        R = (img[:,:,0]).astype(np.float16).tostring()
        G = (img[:,:,1]).astype(np.float16).tostring()
        B = (img[:,:,2]).astype(np.float16).tostring()
        out.writePixels({'R' : R, 'G' : G, 'B' : B})
        out.close()
    except Exception as e:
        raise IOException("Failed writing EXR: %s"%e)


# Read training data (HDR ground truth and LDR JPEG images)

Example #2

Source File: exr_test.py From graphics with Apache License 2.0

5 votes

def _WriteMixedDatatypesExr(filename):
  header = OpenEXR.Header(64, 64)
  header['channels'] = {
      'uint': Imath.Channel(Imath.PixelType(Imath.PixelType.UINT)),
      'half': Imath.Channel(Imath.PixelType(Imath.PixelType.HALF))
  }
  channel_data = {
      'uint': np.zeros([64, 64], dtype=np.uint32).tobytes(),
      'half': np.zeros([64, 64], dtype=np.float16).tobytes()
  }
  output = OpenEXR.OutputFile(filename, header)
  output.writePixels(channel_data)
  output.close()

Example #3

Source File: exr.py From graphics with Apache License 2.0

5 votes

def write_exr(filename, values, channel_names):
  """Writes the values in a multi-channel ndarray into an EXR file.

  Args:
    filename: The filename of the output file
    values: A numpy ndarray with shape [height, width, channels]
    channel_names: A list of strings with length = channels

  Raises:
    TypeError: If the numpy array has an unsupported type.
    ValueError: If the length of the array and the length of the channel names
      list do not match.
  """
  if values.shape[-1] != len(channel_names):
    raise ValueError(
        'Number of channels in values does not match channel names (%d, %d)' %
        (values.shape[-1], len(channel_names)))
  header = OpenEXR.Header(values.shape[1], values.shape[0])
  try:
    exr_channel_type = Imath.PixelType(_np_to_exr[values.dtype.type])
  except KeyError:
    raise TypeError('Unsupported numpy type: %s' % str(values.dtype))
  header['channels'] = {
      n: Imath.Channel(exr_channel_type) for n in channel_names
  }
  channel_data = [values[..., i] for i in range(values.shape[-1])]
  exr = OpenEXR.OutputFile(filename, header)
  exr.writePixels(
      dict((n, d.tobytes()) for n, d in zip(channel_names, channel_data)))
  exr.close()