NEWS
qualpalr 2.0.0.9000
Refactoring
- The package now uses cpp11 instead of Rcpp to bind the C++ code to R.
This should speed up compilation times and reduce dependencies.
qualpalr 2.0.0 (2026-01-29)
Breaking Changes
- The previous method for catering to multiple types of color
vision deficiencies has been revised. Previously, it
incorrectly chained simulations of all the deficiencies together,
which does not work as intended since the operations are not
commutative and hence depend on the order in which they are applied.
Now, instead, the color differences are computed separately for
each type of deficiency (protanopia, deuteranopia, and tritanopia)
as well as normal vision, and the minimum color distance across
all types is maximized. The input of the
cvd argument is
unchanged, but the behavior is different. This change may lead
to different palettes being generated when multiple types of
color vision deficiencies are specified.
New Features
- Added
white_point parameter to qualpal() to allow users to
specify the reference white point for color space conversions.
Available options are "D65" (default, daylight at 6500K), "D50"
(daylight at 5000K, common in printing), "D55" (daylight at
5500K), "A" (incandescent tungsten at 2856K), and "E" (equal
energy). The white point affects how perceptual color distances
are calculated.
qualpalr 1.0.1 (2025-10-17)
Minor Changes
Bug Fixes
- Fixes an edge case when converting RGB colors to a hex representation.
qualpalr 1.0.0 (2025-08-18)
New or Modified Features
qualpal() now uses the CIEDE2000 metric instead of the DIN99d one
by default. Users can still specify the DIN99d metric by passing
metric = "din99d" to qualpal().- The
character method of the qualpal() function now accepts
a name for a predefined palette, such as "ColorBrewer::Set1" or
"Tableau::10", which will use the corresponding palette's
colors as input. Passing one of the old colorspace names
now throws a warning and will be removed in the next major release.
qualpal() now accepts a background color through the bg argument,
which is considered when generating the palette, but not included in the
final palette.- The color difference metric in
qualpal() can now be specified
using the metric argument, which accepts either "din99d" (the default),
"ciede2000", or "cie76". Expect slower performance for "ciede2000".
- The
autopal() function is now deprecated and will be removed int the next major
release. There is no direct replacement.
- There's a new function,
analyze_palette(), which analyzes a categorical
color palette.
qualpal() now has a extend method that allows the user to extend
an existing palette by adding more colors to it. This is useful for
expanding an existing palette to include more colors.- The color space (
list) method of qualpal() now accepts
a specification in the LCHab (HCL) color space, which is
a cylindrical representation of the Lab color space. This is mostly
added to simplify comparisons with other packages that use LCHab
as input. We still recommend using the HSL color space, which is
more intuitive for most users.
- There's a new function,
list_palettes(), which lists all built-in palettes
available in the package, which can thus be used in the new character method
for qualpal(). This includes the predefined palettes from ColorBrewer,
Tableau, and other sources.
- There's a new function,
get_palette(), which retrieves a palette
by name from the built-in palettes.
- The
cvd argument now accepts a named numeric vector, which allows specifying
the severity of color vision deficiency for each type of deficiency.
The names are "protan", "deuter", and "tritan".
- The
cvd_severity argument has been deprecated and will be removed
in the next major release. The cvd argument now handles all cases of color
vision deficiency adaptation directly.
Refactoring
- The entire C++ backend for the package has been rewritten and
outsourced to a separate C++ library, qualpal.
Bug Fixes
- An inconsistency in the conversion from Lab to DIN99d color space,
where the reference of the white point was not modified correctly,
has been fixed.
Performance Improvements
- The color distance computation has been parallelized using
OpenMP.
- All of the heavy lifting is now done in C++, which should
significantly improve performance, especially for larger palettes.
qualpalr 0.4.4 (2023-09-13)
Minor changes
- The dependency on RcppParallel has been dropped. As a result, the
argument
n_threads is now deprecated (and has no effect).
qualpalr 0.4.3 (2018-10-29)
Minor changes
qualpal() gains an argument, n_threads, for specifying the number
of threads to use when computing the distance matrix between colors.- C++ functions call namespaces explicitly using
::.
- Documentation for hue and saturation in
qualpal() has been fixed.
(Closes #2, thanks @jflycn).
qualpalr 0.4.2 (2017-08-28)
Major changes
- Palettes are no longer generated randomly. qualpalr previously started
with a random sample of colors before running the optimization scheme but now
instead picks a starting set of linearly spaced colors.
Minor changes
- C++ functions are registered via Rcpp.
Bug fixes
autopal() erroneously required colorspace to be a string.
qualpalr 0.4.1 (2017-05-15)
Bug fixes
- Fixed
autopal() which was broken since the minimum color difference
returned was always 0 due to a bug in qualpal().
Minor changes
- Now registers compiled functions.
qualpalr 0.4.0 (2017-03-16)
Major changes
autopal() is a new function that tweaks the amount of color vision
deficiency adaptation to match a target color difference.qualpal() argument colorspace now also accepts a matrix or
data.frame of RGB colors.
Minor changes
qualpal() sorts palettes in order of increasing color distinctness.qualpal() argument colorblind has been made defunct.- Documentation for
qualpal() has been improved.
- Colors are now generated with
randtoolbox::torus() instead of
randtoolbox::sobol().
qualpalr 0.3.1 (2016-12-22)
Bug fixes
- Dropped a C++ header that caused the package build to fail
on some platforms.
- Fixed issues with uninitialized variables in the internal farthest points
optimizer.
qualpalr 0.3.0 (2016-12-20)
New features
- Improved algorithm for finding distinct colors. (For details
see this.)
- Revamped the color deficiency handling to include almost all cases of color
deficiency using the methods described in
Machado et al. 2009,
now including tritanopia as well as anomalous trichromacies (deuteranomaly,
tritanomaly, and protanomaly). This is controlled via the
cvd_severity
argument to qualpal() that allows the user to set the severity of color
deficiency to adapt to -- 0 for normal vision and 1 for dichromatic vision
(protanopia, deuteranopia, or tritanopia).
Minor improvements
- Distance and color picking algorithms have been rewritten in C++ using Rcpp,
RcppParallel, and RcppArmadillo.
- Phased out the
... argument to qualpal.
- Lightness range of the predefined rainbow palette increased to [0, 1].
- Changed argument name of
colorblind to cvd (for color vision deficiency)
since the function now adapts to less severe versions of color deficiency. Using
colorblind is deprecated and will throw a warning.
Bug fixes
- Fixed typos and invalid links in the Introduction to qualpalr vignette.
qualpalr 0.2.1 (2016-10-09)
New features
- Dropped daltonization since it effectively transposed the color
subspace given by the user. qualpalr now instead only transforms the given color
subspace to simulate protanopia or deuteranopia and then picks colors. This
has the side-effect of decreasing the distinctness of color palettes when
colorblind is used, but is more consistent with user input.
Bug fixes and minor improvements
- Simulations for tritanopia were dropped since there is no reliable source
to explain how sRGB ranges should be converted (as there is for deuteranopia
and protanopia in Vienot et al 1999).
- Added tests using data from Vienot et al 1999 to check that color blind
simulations work properly.
- Fixed a sampling bug wherein the square root of saturation was taken after
scaling to the provided range, which generated different ranges than intended.
- Switched to the sobol quasi-random sequence instead of torus.
qualpalr 0.2.0
New features
- Redesigned the method by which qualpal picks colors. Now initializes a point
cloud of colors, projects it to DIN99d space, and picks points greedily.
- Introduced real methods of adapting colors to color blindness by daltonizing
color subspaces before picking colors from them.
- The introduction to qualpalr vignette has been expanded with a thorough
description of how qualpalr picks colors.
Bug fixes and minor improvements
- Moved from using
grDevices::convertColor to formulas from
Bruce Lindbloom for color conversions,
since the former function inaccurately converts colors.
- Deprecated
... in qualpal since the function no longer uses an optimizer.