Introduction

OpenEXR is an image format developed by ILM. Its main innovation is support for high dynamic range; it supports floating point pixels.

This module provides Python bindings for the OpenEXR C++ libraries. They allow you to read and write OpenEXR files from Python.

Note that this module only loads and stores image data. It does not do any image manipulation operations. For that you might want to use one of:

• Python’s standard array module. You can access the raw data of FLOAT and UINT images as a 1D array.

  >>> import OpenEXR, Imath, array
  >>> pt = Imath.PixelType(Imath.PixelType.FLOAT)
  >>> redstr = OpenEXR.InputFile("GoldenGate.exr").channel('R', pt)
  >>> red = array.array('f', redstr)
  >>> print red[0]
  0.0612182617188
  

• The Python Imaging Library. This library supports a single FLOAT channel image format, as a 2D array.

  >>> import OpenEXR, Imath, Image
  >>> pt = Imath.PixelType(Imath.PixelType.FLOAT)
  >>> golden = OpenEXR.InputFile("GoldenGate.exr")
  >>> dw = golden.header()['dataWindow']
  >>> size = (dw.max.x - dw.min.x + 1, dw.max.y - dw.min.y + 1)
  >>> redstr = golden.channel('R', pt)
  >>> red = Image.fromstring("F", size, redstr)
  >>> print red.getpixel((0, 0))
  0.0612182617188
  

• Numeric or NumPy. It’s just math, so you will have to write your own imaging operations. Supports UINT and FLOAT formats. Supports 2D arrays.

  >>> import OpenEXR, Imath, numpy
  >>> pt = Imath.PixelType(Imath.PixelType.FLOAT)
  >>> golden = OpenEXR.InputFile("GoldenGate.exr")
  >>> dw = golden.header()['dataWindow']
  >>> size = (dw.max.x - dw.min.x + 1, dw.max.y - dw.min.y + 1)
  >>> redstr = golden.channel('R', pt)
  >>> red = numpy.fromstring(redstr, dtype = numpy.float32)
  >>> red.shape = size
  >>> print red[0, 0]
  0.0612182617188
  

• Module vop. NumPy subset, but faster. Supports FLOAT and HALF. 1D arrays only.

  >>> import OpenEXR, Imath, vop
  >>> pt = Imath.PixelType(Imath.PixelType.FLOAT)
  >>> redstr = OpenEXR.InputFile("GoldenGate.exr").channel('R', pt)
  >>> red = vop.fromstring(redstr)
  >>> print red[0]
  0.0612182617188
  

• OpenCV. Supports multi channel UINT and FLOAT formats. Supports 2D arrays.

  >>> import OpenEXR, Imath, cv
  >>> pt = Imath.PixelType(Imath.PixelType.FLOAT)
  >>> golden = OpenEXR.InputFile("GoldenGate.exr")
  >>> dw = golden.header()['dataWindow']
  >>> size = (dw.max.x - dw.min.x + 1, dw.max.y - dw.min.y + 1)
  >>> redstr = golden.channel('R', pt)
  >>> red = cv.CreateMat(size[1], size[0], cv.CV_32FC1)
  >>> cv.SetData(red, redstr)
  >>> print red[0, 0]
  0.0612182617188