# Algorithms

The algorithms involved in the C-Munipack software at the various stages of the data processing are described in detail in this section. Its purpose is to explain to a curious reader how the source frames and the photometry files are handled, what the numbers and graphs mean and how exactly they are derived. I do not claim that I have invented the algorithms, whenever possible, proper references to the original materials are given.

In the following text, reference is often made to “bad” and “overexposed” pixels. A pixel is regarded as a bad pixel if its value is equal to or less than the value of the first configurable parameter “Minimum pixel value”. Usually this parameter is set to zero, the lowest possible value that can be stored in a source image. An overexposed pixel has a value equal to or greater than the value of the second configurable parameter “Maximum pixel value”. This configuration parameter should be set to a value at which the analog-to-digital converter saturates, but can be set to a lower value to exclude a higher part of the intensity range where response of a detector is not linear enough. In the correction algorithms, both bad and overexposed pixels are excluded from the computations.

- Dark-frame correction
- Flat-frame correction
- Bias-frame correction
- Master dark frame
- Master flat frame
- Master bias frame
- Star detection
- Aperture photometry
- Frame matching
- Tracking a moving target
- Artificial comparison star
- Finding variables
- Frame merging
- Heliocentric correction
- Air mass coefficient
- Robust mean

See also: [berry00] and [hampel05].