Qtpfsgui is a free and open source software program that aids in the HDR imaging process. HDR refers to High Dynamic Range. HDRI refers to High Dynamic Range Imaging. HDR images are useful for 3D rendering as they can be used as vastly superior Environmental Maps. The usage of HDR (or HDRI) environment maps often results in very realistic 3D renderings.
It can be used to edit and manipulated HDR images. Additionally, it is able to generate HDR image files from Tiff and Jpeg images. These Tiff or Jpeg files will need to have different versions of the same scene shot with different exposure settings.
Qtpfsgui also sports Tone mapping ability. This allow HDR files to be saved as LDR formats such as Jpeg and Tiffs.
This software is available as Windows, Mac OSX and Linux versions. You can download Qtpfsgui from qtpfsgui.sourceforge.net/
Hope that this info is helpful. 🙂