How do I get pixel by pixel depth data out of a .exr file? I have been trying to get pixel by pixel depth data out of a .exr file.  I am using blender and rendering with Lux Render.  I need to get pixel by pixel depth data, and have read that if I use the z-buffer in blender and render, then save it as a .exr file from Lux Render, there should be pixel by pixel depth data in the .exr file.  However, I have not been able to read the .exr.  I have access to Matlab.  Can anyone help me with this?
Enable the Z buffer on the output settings:



To check if the Z buffer is correctly rendered, you can load the OpenEXR file in the compositor and add a normalize node to visualize the Z-channel: