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=== Features in brief === | === Features in brief === | ||
| − | * | + | * Providing basic information about the images or other FITS data, pixel statistics. |
* Conversion of FITS images to more easily presentable formats. | * Conversion of FITS images to more easily presentable formats. | ||
* Querying and modification of FITS header keywords. | * Querying and modification of FITS header keywords. | ||
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* Generation of artificial images. | * Generation of artificial images. | ||
* Detection and characterization of stellar profiles. | * Detection and characterization of stellar profiles. | ||
| − | * Coordinate list manipulation (fit and evaluation of geometric transformations, point matching, pair matching, matching by identifiers, ...) | + | * Coordinate list manipulation (fit and evaluation of geometric transformations, point matching, pair matching, cross-matching of catalogues and source lists, matching by identifiers, ...) |
| − | * | + | * Instrumental photometry (aperture, image subtraction, analytic profile modelling, point-spread functions and various other sophisticated combinations of these). |
* Regression analysis and general numeric data manipulation. | * Regression analysis and general numeric data manipulation. | ||
| − | * | + | * The tasks are optimized for shell-level parallel processing. |
| + | |||
| + | === Features by [[tasks]] === | ||
| + | |||
| + | ==== [[fiarith]] ==== | ||
| + | * Basic arithmetic operations on images. | ||
| + | * Operations on individual pixels. | ||
| + | * Creation of images where the pixel intensities are are functions of the coordinates. | ||
| + | |||
| + | ==== [[ficalib]] ==== | ||
| + | * Performing simple arithmetic operations on a bunch of images. | ||
| + | * Performing pixel mask modification on a bunch of images. | ||
| + | * Trimming of a set of images. | ||
| + | |||
| + | ==== [[ficombine]] ==== | ||
| + | * Combination of a set of images into one image using various averaging and stacking methods. | ||
| + | |||
| + | ==== [[ficonv]] ==== | ||
| + | * Fitting optimal convolution transformation between a reference image and an input image. | ||
| + | * Application of existing convolution transformation on a reference image. | ||
| + | * Performing image subtraction using a reference image and an input image either by knowing the convolution transformation in advance or by fitting the optimal one during the process. | ||
| + | * Management of so-called kernel files describing these convolution transformations. | ||
| + | |||
| + | ==== [[fiheader]] ==== | ||
| + | * Extracting various FITS keywords and the associated values from individual or a bunch of files. | ||
| + | * Modification of FITS keywords in an individual or in a bunch of files. | ||
| + | * Adding or removing FITS keywords to/from an individual or to/from a bunch of files. | ||
| + | |||
| + | ==== [[fiign]] ==== | ||
| + | * Performing low-level manipulation of masks associated to FITS images. | ||
| + | * Adding or removing masks (and various mask layers) to/from a FITS image. | ||
| + | * Conversions between various mask types. | ||
| + | * Adding or removing mask bits as the function of the pixel values or based on the characteristics of pixels. | ||
| + | |||
| + | ==== [[fiinfo]] ==== | ||
| + | * Reporting a brief or a detailed summary about a FITS file, including primary image and various extensions (such as additional images, binary tables or textual tables). | ||
| + | * Extracting raw information from FITS files, including dumping of image pixel data, mask bits, binary table data and textual table data. | ||
| + | * Conversion of FITS images to PNM (PPM, PGM) format using | ||
| + | ** various scaling functions, such as linear, logarithmic, squared, square root, etc., | ||
| + | ** scale limit determinations, such as minimum, maximum values, zscale, histrogram normalization, values derived from cumulative pixel intensity distributions, etc., and | ||
| + | ** various color palettes, including grey-scale, color, custom defined color as well as 8-bit and 16-bit dynamics. | ||
| + | * Extracting simple pixel statistics from FITS image files. | ||
| + | |||
| + | ==== [[fiphot]] ==== | ||
| + | * Performing aperture photometry on normal images. | ||
| + | * Performing aperture photometry on subtracted images by considering the information related to image convolution (if it has been applied in advance). | ||
| + | * Determination of background level using the classic ways (considering pixels in annuli around the targets) as well as treating the background to be known in advance. | ||
| + | * Support for arbitrary-shaped apertures using polygonal approximations by involving arbitrary number of boundary segments. | ||
| + | * Conversion of fluxes to magnitudes. | ||
| + | * Computation of flux and/or magnitude uncertainties by involving as many noise sources as possible (mainly background noise and photon noise). | ||
| + | * Computation shape centroid coordinates and shape parameters, refinement of centroid coordinates. | ||
| + | * Computation of the respective uncertainties of centroid coordinates and shape parameters by involving as many noise sources as possible. | ||
| + | * Fitting and adjusting of large-scale flux variations on subtracted images considering a dependence on the coordinates and intrinsic colors in a form of arbitrary-order polynomials. | ||
| + | * Treatment of nearby sources by removing them from the background determination. | ||
| + | * Flagging the sources using the constraints defined by the masks associated to the FITS images. | ||
| + | |||
| + | ==== [[firandom]] ==== | ||
| + | * Creation of images. | ||
| + | * Simulation of various noise sources, such as background noise and photon noise. | ||
| + | * Implantation of sources having various fluxes and shape parameters (including analytical shape models as well as external point-spread functions). | ||
| + | * Quantization of pixel flux values. | ||
| + | * Creation of random lists of objects. | ||
| + | |||
| + | ==== [[fistar]] ==== | ||
| + | * Extracting list of point sources and the corresponding geometric parameters (centroid coordinates, shape paremeters, etc.). | ||
| + | * Fitting of (optionally space-varying) point-spread function based on the detected sources, including sub-pixel level sampling. | ||
| + | |||
| + | ==== [[fitrans]] ==== | ||
| + | * Transformation of FITS images and the corresponding pixel masks. | ||
| + | * Extractions of a single or multiple layers from a FITS data cube. | ||
| + | |||
| + | ==== [[grcollect]] ==== | ||
| + | * Transposing large amount of data based on unique keys found in the input data series. | ||
| + | |||
| + | ==== [[grmatch]] ==== | ||
| + | * Matching two data files using various criteria: | ||
| + | ** identifier matching (unique identifiers or keys are matched), | ||
| + | ** coordinate matching (points are matched based on Cartesian distance and topological correspondence) | ||
| + | ** point matching and the derivation of the corresponding analytic transformation (only in planar case) | ||
| + | * Fine-tuning of point matching algorithms using various criteria | ||
| + | |||
| + | ==== [[grtrans]] ==== | ||
| + | * Derivation of best-fit spatial transformation between a matched list of coordinates. | ||
| + | * Application of transformation data to a list of coordinates. | ||
| + | * Application of astronomy-specific transformations on a list of coordinates. | ||
| + | |||
| + | ==== [[lfit]] ==== | ||
| + | * Regression analysis and best-fit parameters estimation of input data by involving various algorithms, such as | ||
| + | ** linear least squares fitting; | ||
| + | ** non-linear least squares fitting, based on | ||
| + | *** Levenberg-Marquard procedure, | ||
| + | *** downhill simplex minimization, | ||
| + | *** Markov Chain Monte Carlo, etc. | ||
| + | ** Mapping of {{math|<VAR>χ<sup>2</sup></VAR>}} space | ||
| + | * Uncertainty estimations by involving various procedures, such as | ||
| + | ** Linear error propagation and covariance matrix analysis, | ||
| + | ** Markov Chain Monte Carlo, | ||
| + | ** Bootsrapping, etc. | ||
| + | * Evaluation of functions. | ||
| + | * Fully symbolic operations, incuding analytical computation of partial derivatives. | ||
| + | * Definition of additional functions during run-time. | ||
| + | * User-defined and time-consuming functions can be implemented using shared libraries. | ||
| + | * Various built-in functions useful in astronomical data analysis. | ||
| + | |||
| + | {{Documentation}} | ||
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