# Tint
[](https://travis-ci.org/tlux/tint)
[](https://coveralls.io/github/tlux/tint?branch=master)
[](https://hex.pm/packages/tint)
An Elixir library allowing calculations with colors and conversions between
different colorspaces.
Currently supports the following color models:
* [RGB](https://en.wikipedia.org/wiki/RGB_color_space)
* [CMYK](https://en.wikipedia.org/wiki/CMYK_color_model)
* [HSV](https://en.wikipedia.org/wiki/HSL_and_HSV)
* L\*a\*b\* ([CIELAB](https://en.wikipedia.org/wiki/CIELAB_color_space))
* XYZ ([CIE 1931](https://en.wikipedia.org/wiki/CIE_1931_color_space))
* [DIN99](https://de.wikipedia.org/wiki/DIN99-Farbraum)
## Prerequisites
* Elixir 1.8 or greater
## Installation
The package can be installed by adding `tint` to your list of dependencies in
`mix.exs`:
```elixir
def deps do
[
{:tint, "~> 1.1"}
]
end
```
## Usage
### Colorspaces
#### RGB
```elixir
iex> Tint.RGB.new(255, 0, 0)
#Tint.RGB<255,0,0 (#FF0000)>
```
or
```elixir
iex> import Tint.Sigil
...> ~K[255, 0, 0]r
#Tint.RGB<255,0,0 (#FF0000)>
```
Using hex codes:
```elixir
iex> Tint.RGB.from_hex("#FF0000")
{:ok, #Tint.RGB<255,0,0 (#FF0000)>}
iex> Tint.RGB.from_hex("#F00")
{:ok, #Tint.RGB<255,0,0 (#FF0000)>}
iex> Tint.RGB.from_hex("FF0000")
{:ok, #Tint.RGB<255,0,0 (#FF0000)>}
iex> Tint.RGB.from_hex!("F00")
#Tint.RGB<255,0,0 (#FF0000)>
iex> Tint.RGB.from_hex("invalid")
:error
iex> Tint.RGB.from_hex!("invalid")
** (ArgumentError) Invalid hex code: invalid
```
or
```elixir
iex> import Tint.Sigil
...> ~K[#FF0000]
#Tint.RGB<255,0,0 (#FF0000)>
```
To convert RGB colors back to hex codes:
```elixir
iex> color = Tint.RGB.new(255, 0, 0)
...> Tint.RGB.to_hex(color)
"#FF0000"
```
#### CMYK
```elixir
iex> Tint.CMYK.new(0.55, 0.26, 0.24, 0.65)
#Tint.CMYK<55%,26%,24%,65%>
```
or
```elixir
iex> import Tint.Sigil
...> ~K[0.55, 0.26, 0.24, 0.65]c
#Tint.CMYK<55%,26%,24%,65%>
```
#### HSV
```elixir
iex> Tint.HSV.new(25.8, 0.882, 1)
#Tint.HSV<25.8°,88.2%,100%>
```
or
```elixir
iex> import Tint.Sigil
...> ~K[25.8, 0.882, 1]h
#Tint.HSV<25.8°,88.2%,100%>
```
#### CIELAB
```elixir
iex> Tint.Lab.new(53.2329, 80.1068, 67.2202)
#Tint.Lab<53.2329,80.1068,67.2202>
```
or
```elixir
iex> import Tint.Sigil
...> ~K[53.2329, 80.1068, 67.2202]c
#Tint.Lab<53.2329,80.1068,67.2202>
```
#### DIN99
```elixir
iex> Tint.DIN99.new(53.2329, 80.1068, 67.2202)
#Tint.DIN99<53.2329,80.1068,67.2202>
```
or
```elixir
iex> import Tint.Sigil
...> ~K[53.2329, 80.1068, 67.2202]d
#Tint.DIN99<53.2329,80.1068,67.2202>
```
### Conversion
```elixir
iex> rgb = Tint.RGB.new(255, 0, 0)
...> Tint.to_hsv(rgb)
#Tint.HSV<0°,100%,100%>
```
The complete list:
```elixir
Tint.to_cmyk(color)
Tint.to_din99(color)
Tint.to_hsv(color)
Tint.to_lab(color)
Tint.to_rgb(color)
Tint.to_xyz(color)
```
Alternatively you can use `convert/2` and `convert!/2`:
```elixir
Tint.convert(color, :rgb)
Tint.convert(color, Tint.RGB)
Tint.convert!(color, :hsv)
```
Currently, only RGB can be converted to any other colorspace.
### Color Distance
There are a couple of functions to calculate the distance between two colors.
#### Euclidean Distance
The
[Euclidean distance](https://en.wikipedia.org/wiki/Color_difference#Euclidean)
can be calculated on RGB colors. Calculating the Euclidean distance is very fast
but may not be very precise. If you want maximum precision use the CIEDE2000
algorithm.
```elixir
iex> Tint.RGB.euclidean_distance(~K[#FFFFFF], ~K[#000000])
441.6729559300637
```
You can also define weights for the individual red, green and blue color
channels:
```elixir
iex> Tint.RGB.euclidean_distance(~K[#FFFFFF], ~K[#000000], weights: {2, 4, 3})
765.0
```
To find the nearest color from a given palette:
```elixir
iex> Tint.RGB.nearest_color(~K[#CC0000], [~K[#009900], ~K[#FF0000]])
#Tint.RGB<255,0,0 (#FF0000)>
```
#### CIEDE2000
[CIEDE2000](https://en.wikipedia.org/wiki/Color_difference#CIEDE2000) is an
algorithm that operates on the CIELAB colorspace. It is very slow compared to
the Euclidean distance algorithm but it is optimized to human color perception.
```elixir
iex> Tint.Lab.ciede2000_distance(~K[#FF0000], ~K[#000000])
50.3905024704449
```
To find the nearest color from a given palette:
```elixir
iex> Tint.Lab.nearest_color(~K[#FF0000], [~K[#009900], ~K[#CC0000]])
#Tint.RGB<204,0,0 (#CC0000)>
```
### Complementary Color
```elixir
iex> Tint.RGB.complementary_color(~K[#FF0000])
#Tint.RGB<0,255,255 (#00FFFF)>
```
## Docs
The API docs can be found at [HexDocs](https://hexdocs.pm/tint).
