:mod:`colorsys` --- Conversions between color systems
=====================================================

.. module:: colorsys
   :synopsis: Conversion functions between RGB and other color systems.
.. sectionauthor:: David Ascher <da@python.net>


The :mod:`colorsys` module defines bidirectional conversions of color values
between colors expressed in the RGB (Red Green Blue) color space used in
computer monitors and three other coordinate systems: YIQ, HLS (Hue Lightness
Saturation) and HSV (Hue Saturation Value).  Coordinates in all of these color
spaces are floating point values.  In the YIQ space, the Y coordinate is between
0 and 1, but the I and Q coordinates can be positive or negative.  In all other
spaces, the coordinates are all between 0 and 1.

.. seealso::

   More information about color spaces can be found at
   http://www.poynton.com/ColorFAQ.html and
   http://www.cambridgeincolour.com/tutorials/color-spaces.htm.

The :mod:`colorsys` module defines the following functions:


.. function:: rgb_to_yiq(r, g, b)

   Convert the color from RGB coordinates to YIQ coordinates.


.. function:: yiq_to_rgb(y, i, q)

   Convert the color from YIQ coordinates to RGB coordinates.


.. function:: rgb_to_hls(r, g, b)

   Convert the color from RGB coordinates to HLS coordinates.


.. function:: hls_to_rgb(h, l, s)

   Convert the color from HLS coordinates to RGB coordinates.


.. function:: rgb_to_hsv(r, g, b)

   Convert the color from RGB coordinates to HSV coordinates.


.. function:: hsv_to_rgb(h, s, v)

   Convert the color from HSV coordinates to RGB coordinates.

Example::

   >>> import colorsys
   >>> colorsys.rgb_to_hsv(.3, .4, .2)
   (0.25, 0.5, 0.4)
   >>> colorsys.hsv_to_rgb(0.25, 0.5, 0.4)
   (0.3, 0.4, 0.2)