News for the HDRL (High-level Data Reduction Library)
=====================================================

Version 1.6.0 (2026-06-02)
--------------------------

  * Updated the HDRL catalogue to follow ESO Phase 3 conventions.
  * Kept HDRL usable as a convenience library as before, and added
    support to install it as a standalone third-party library with
    --enable-standalone.
  * Resampling: Fixed PIPE-12792 bug where rotated WCS (with significant
    off-diagonal CD matrix terms) caused unreasonably large output grid
    dimensions and memory allocation failures. The fix automatically
    corrects pixel scale values (delta_ra/delta_dec) when they are
    incorrectly extracted using only diagonal CD matrix elements,
    ensuring proper computation accounting for rotation.
  * Included various QC and bug-fix improvements (see ChangeLog for
    details).
  * Licensing and docs: clarified GPLv2-or-later licensing
    (homogenised headers and FSF address, replaced LICENSE with a
    canonical COPYING, and added GNU-style distribution files (README,
    INSTALL, AUTHORS, ChangeLog, NEWS) that are shipped in the tarball
    and installed under docdir for standalone builds.


Version 1.5.0 (2021-09-30)
--------------------------

  * Limiting magnitude: computation as defined in the ESO Phase 3
    Standard (magnitude of an unresolved source with flux 5 times
    the noise background).
  * Statistics: added mode of a distribution for collapsing
    imagelists and image statistics; error from data via analytic
    or bootstrap Monte Carlo. Mean, weighted mean, min-max rejected
    mean, kappa-sigma clipped mean, median, and mode are supported.
  * API change: hdrl_overscan_parameter_create_parlist() and
    hdrl_collapse_parameter_create_parlist() now take an additional
    default mode parameter.
  * Barycentric correction: wavelength shift to compensate for
    observer motion with respect to the solar system barycenter.
    Implementation uses the ERFA library (IAU SOFA-derived).
  * Build: GSL is now a direct dependency (for the limiting magnitude
    module). ERFA and libcurl were added for barycentric correction
    and related functionality.


Version 1.4.0 (2021-02-12)
--------------------------

  * Resampling: 2D images and 3D cubes onto a common grid with six
    interpolation methods (Nearest, Linear, Quadratic, Renka,
    Drizzle, Lanczos).
  * Catalogue: pixels with value exactly 0 are no longer
    automatically added to the confidence map as bad; behaviour
    removed for clearer control.


Version 1.3.0 (2018-10-01)
--------------------------

  * Fixed pattern noise: detection via power spectrum (e.g. pick
    noise, quasi-periodic patterns).
  * Documentation: corrected description of Strehl ratio variables
    m1_radius and m2_radius (code was already correct).
  * Spectral efficiency: fixed sign error in atmospheric
    correction (equation and code).


Version 1.2.0 (2018-04-01)
--------------------------

  * Strehl ratio: computation for AO-assisted instrumentation
    quality control (peak intensity vs diffraction-limited).
  * Spectral efficiency: as a function of wavelength from flux
    standard stars vs reference spectrum.
  * Spectral response: telluric correction (optional) and response
    calculation as a function of wavelength.
  * Differential atmospheric refraction: Filippenko (1982) algorithm
    with Owens formula for water vapour pressure.
  * Effective air mass computation.


Version 1.1.0 (2017-04-01)
--------------------------

  * Object catalogue generation: astrometric and photometric
    calibration; local sky background estimation, object/blend
    detection (Irwin 1985), parametrisation (astrometry,
    photometry, shape analysis).


Version 1.0.0 (2015-11-26)
--------------------------

  * Fringe correction: master-fringe image via Gaussian mixture
    model; scaled master used to remove fringes from single images.


Version 0.9.0 (2015-05-01)
--------------------------

  * Master flatfield: algorithms to derive master flatfield.
  * Strehl ratio: initial implementation.


Version 0.8.0 (2014-12-15)
--------------------------

  * Clipping: sigma clipping now uses scaled Median Absolute
    Deviation (MAD) instead of interquartile range (IQR) for
    robust RMS; better for low-number statistics and high
    fraction of affected pixels (e.g. cosmic rays).
  * Documentation: pipeline integration details updated.


Version 0.7.0 (2014-09-17)
--------------------------

  * Bad pixel detection: various methods for bad pixel detection
    (see bad-pixel module documentation).


Version 0.6.0 (2013-11-29)
--------------------------

  * First prototype release of the HDRL library.


Version 0.5.0 (2013-08-09)
--------------------------

  * Master bias and master dark computation and handling.


Version 0.4.0 (2013-04-26)
--------------------------

  * Overscan computation and correction.
