Kovesi.Rd
\name{Kovesi}
\alias{Kovesi}
\docType{data}
\title{
Colour Sequences with Uniform Perceptual Contrast
}
\description{
A collection of 41 different sequences of colours,
each sequence having a uniform perceptual contrast over its whole
range. These sequences make very good colour maps which avoid
introducing artefacts when displaying image data.
}
\usage{data(Kovesi)}
\format{
A \code{\link{hyperframe}} with the following columns:
\tabular{ll}{
\code{linear} \tab Logical: whether the sequence is linear. \cr
\code{diverging} \tab Logical: whether the sequence is diverging. \cr
\code{rainbow} \tab Logical: whether the sequence is a rainbow. \cr
\code{cyclic} \tab Logical: whether the sequence is cyclic. \cr
\code{isoluminant} \tab Logical: whether the sequence is isoluminant. \cr
\code{ternary} \tab Logical: whether the sequence is ternary. \cr
\code{colsig} \tab Character: colour signature (see Details) \cr
\code{l1}, \code{l2} \tab Numeric: lightness parameters \cr
\code{chro} \tab Numeric: average chroma (percent) \cr
\code{n} \tab Numeric: length of colour sequence \cr
\code{cycsh} \tab Numeric: cyclic shift (percent) \cr
\code{values} \tab: Character: the colour values.
}
}
\details{
Kovesi (2014, 2015) presented a collection of colour sequences
that have uniform perceptual contrast over their whole range.
The dataset \code{Kovesi} provides these data. It is a
\code{hyperframe} with 41 rows, in which each row provides information
about one colour sequence.
Additional information in each row specifies whether the
colour sequence is \sQuote{linear}, \sQuote{diverging},
\sQuote{rainbow}, \sQuote{cyclic}, \sQuote{isoluminant}
and/or \sQuote{ternary} as defined by Kovesi (2014, 2015).
The \sQuote{colour signature} is a string composed of letters
representing the successive hues, using the following code:
\tabular{ll}{
r \tab red \cr
g \tab green\cr
b \tab blue \cr
c \tab cyan \cr
m \tab magenta \cr
y \tab yellow \cr
o \tab orange \cr
v \tab violet \cr
k \tab black \cr
w \tab white \cr
j \tab grey (j rhymes with grey)
}
For example \code{kryw} is the sequence from black to red to yellow to
white.
The column \code{values} contains the colour data themselves.
The \code{i}th colour sequence is \code{Kovesi$values[[i]]},
a character vector of length 256.
}
\source{
Dr Peter Kovesi, Centre for Exploration Targeting,
University of Western Australia.
}
\references{
Kovesi, P. (2014)
Website \emph{CET Uniform Perceptual Contrast Colour Maps}
\url{www.peterkovesi.com/projects/colourmaps/}
Kovesi, P. (2015)
Designing colour maps with uniform perceptual contrast.
Manuscript submitted for publication.
}
\examples{
Kovesi
LinearBMW <- Kovesi$values[[28]]
plot(colourmap(LinearBMW, range=c(0,1)))
## The following would be suitable for spatstat.options(image.colfun)
BMWfun <- function(n) { interp.colours(LinearBMW, n) }
}
\keyword{datasets}