Revision as of 14:37, 4 March 2014 by Lock42 (talk | contribs) (Manual page for Siril: -> display mode)

Manual page for Siril

Siril is an astronomical image processing free software, see main page for more details.

A powerful astronomical viewer

A Display Mode viewer is used to improve the visibility of an image, but without altering its pixel data in any way.

  • Linear: This is the default mode in Siril. Pixels are displayed from the darkest to the brightest in a linear scale.
  • Logarithm: Same than linear instead that here the scale is logarithmic. The operation emphase simultenaously information in faint and bright levels of the image.
  • Square root: This transformation, takes the square root of each pixels. The result is close to the logarithm mode.
  • Squared: Same than before but using the squared of each pixels.
  • Asinh: The inverse hyperbolic sine is the most commonly used, it reproduces the perceptual ability of the human eye, which can accommodate to perceive dramatically different levels of brightness simultaneously. Asinh is close to the logarithm mode but has a better behavior around zero.
  • Histogram: This mode increases the contrast of the image by increasing the dynamic range of intensity given to pixels with the most probable intensity values.

This video tutorial shows the different modes you can use to display your images.

Reducing green tint in processed images

This video tutorial shows how to remove the green tint in processed images using the graphical user interface. This function can also be accessed from the command line, with the rmgreen command.

Tutorial for a complete processing

An illustrated tutorial has been compiled to describe the usual processing steps, starting from RAW DSLR images to stacking.


Siril provides a few astrometry tools.

In particular, the PSF function that uses the Levenberg–Marquardt algorithm for minimization. See the dedicated page for a video tutorial.