Introducing PIPP - Planetary Imaging PreProcessor

PIPP is a Windows application designed for pre-processing planetary images before stacking them with image stacking software such as Registax.  PIPP's main purpose is to crop each image frame and select only the best quality frames to reduce the memory and processing requirements of the stacking software.  For example, this would allow the best 1500 frames from a 7200 frame AVI (2 minute AVI at 60 fps) to be cropped ready for stacking by Registax.  On my PC, Registax does not handle AVI files with that many frames but can easily handle 1500 pre-processed bitmap files so this is very useful.

PIPP was originally written to speed up the my own processing of the multitude large AVI files that that each planetary imaging session seems to generate.  Now that PIPP has reached the point where it does actually speed up my processing workflow I decided to make it available to others to see if they find it useful and maybe give a little back to the astronomy community.

PIPP's functions:

  • Load a sequence of images from supported video files, SER video files or TIFF/BMP/FITS/JPEG/RAW camera image files.
  • Calibrate frames with dark, flat and dark flat calibration frames.
  • Debayer raw frames from colour cameras to produce colour frames.
  • Check each frame contains a planet that is completely on the image and discard any frames that do not.
  • Check for and discard overexposed frames.
  • Centre the planet in the frames.
  • Offset the centred planet.
  • Crop each frame around the centred planet.
  • Apply a fixed gain to each frame.
  • Apply a fixed gamma correct to each frame.
  • Apply a median noise filter to each frame.
  • Stretch histogram for each frame (equalising R, G and B channels for colour images).
  • Estimate the quality of each frame and reorder the processed frames in order of quality.
  • Keep only the number of best quality frames specified by the user.
  • Split colour frames into R, G and B frames.
  • Save processed frames as a sequence of TIFF/BMP/FITS image files, as a single AVI/SER video file ready for stacking or archiving or as an animated GIF for sharing online.

PIPP's functionality continues to be extended over time.

Supported Platforms

Current supported platforms:

An updated version of PIPP that will run natively on Linux and Mac OS X as well as Windows is currently being worked on.  Here are a few features of this version in case anyone in interested:

  • All C# .net code to be replaced with C++ code so the entire program will be C++.
  • The Qt framework to be used for cross platform GUI support.
  • Improved integration between the GUI and the core code will hopefully allow a more natural user interface to run (no need for the 'Test Options' button).
  • Support for languages other than English will be added.  This will require some volunteer translators!
  • This version will be released under an open source license so that other developers will be able to contribute bug fixes and new features.
  • A large rewrite of the internal code to tidy it up before releasing the source.

This work is taking longer than hoped, but it is now PIPP's highest development priority.


Thanks for Martin Lewis ( for all his help with testing PIPP, his feedback and suggestions have been invaluable.

Thanks also to Anthony Wesley for permission to use the quality estimation source code from his Ninox planetary imaging software ( in PIPP.  This is the basis for PIPP's quality estimation algorithm.  In truth, although PIPP has moved on quite a bit now, it was originally inspired by Ninox.

Thanks also go to Heiko Wilkens, author of the Lucam Recorder image acquisition software (, for permission to incorporate his proprietary SER video format in PIPP.

Thanks go out to Dave Coffin for all his work on DCRAW and making the code available for others to use.  This is the code that enables PIPP to decode almost any camera raw image format.