• Tests and Misc

DeepSkyStacker: The Free Preprocessing Powerhouse!

DeepSkyStacker: My New Favorite for Astro Preprocessing!

I’ve just stumbled upon a little gem for preprocessing our astro images: DeepSkyStacker, a fantastic freeware developed by Luc Coiffier. This software simplifies all the deep-sky image preprocessing steps as much as possible, covering:

  • Image registration
  • Image stacking
  • Simple processing to quickly visualize the final result
  • Saving the resulting image in 16 or 32-bit TIFF or FITS formats.

The interface is super user-friendly and intuitive. Its calculation engine is incredibly powerful and handles multi-core and multi-processor systems exceptionally well. On my Intel Core 2 Quad, it’s about ten times faster than Registar! Seriously impressive, especially considering the results are flawless. The software natively supports most RAW formats, which is a huge plus, saving you from intermediate conversions.

Key Features (according to the official website):

  • Automatic registration of a series of images
  • Automatic star detection across the entire surface of each image
  • Registration with sub-pixel precision
  • Automatic de-rotation
  • Automatic creation and application of offsets, flats, and darks
  • Alignment and stacking with sub-pixel precision
  • Supports 8, 16, and 32-bit color and monochrome TIFF; 8, 16, 32, and 64-bit color and monochrome FITS; JPEG, BMP, PNG
  • Native support for most digital camera RAW formats on the market (CR2, NEF, CRW, DNG, etc.), bypassing the need for intermediate formats (TIFF or others).
  • Darks, Flats, and Offsets calculated from and applied directly to the RAW file before any interpolation.
  • Stacking methods: average, median, kappa-sigma clipping, auto-adaptive weighted average, entropy-weighted average, maximum…
  • Preview for all image formats (including RAW)
  • Initial processing step allowing adjustment of RGB levels, luminance curve, and saturation level
  • Saving results in 16 or 32-bit TIFF or FITS formats, with or without applied adjustments
  • Easy-to-use interface
  • Optimal memory usage: whether you have 10 or 500 images to stack, the same amount of memory is required.
  • Utilizes all available processors (hyperthreading, multi-processor, dual-core or quad-core CPUs).
  • Available in French, Spanish, English, Czech, and Italian.

Advanced Features

  • Automatic determination of Darks, Flats, and Offsets to apply based on exposure times and ISO sensitivity of the images to be stacked.
  • Multiple methods used for optimal Bayer matrix utilization in RAW formats, minimizing the effects of destructive missing pixel interpolation.
  • Option for automatic hot pixel detection during registration
  • Options for automatic hot pixel and bad column detection and removal during stacking
  • Automatic flat frame calibration to equalize brightness differences
  • Automatic background calibration across different images
  • Automatic dark frame optimization
  • Automatic use of bicubic, bilinear, or biquadratic transformation for alignment based on the number of stars.
  • Creation of file lists to speed up loading frequently used files (flats, darks, offsets, etc.)
  • Comet image stacking
  • Manual editing of star and comet positions
  • Drizzle option (x2 or x3) for stacking.
  • Ability to use 16-bit monochrome FITS files as RAW files (by utilizing a Bayer matrix).
  • Use of file groups to simplify managing files from multiple sessions on the same object
  • Options to create all files corresponding to calibrated and registered images
  • Debloom
  • Cosmetic options to detect and clean residual hot/cold pixels on calibrated images.
  • Star mask creation functionality
  • Batch processing functionality
  • Command-line version.