Round corners
=============

Usage: `round\_corner(a\|b,r,g,b,[transparent])`

Description
-----------

This filter adds rounded corners to the image using the specified color
as background.

Arguments
---------

- ``a|b`` - amount of pixels to use as radius. The argument ``b`` is not required, but it specifies the second value for the ellipsis used for the radius.
- ``transparent`` - Optional. If set to true/1, the background will be transparent.

Examples
--------

.. image:: images/tom_before_brightness.jpg
    :alt: Picture before the round corners filter filter

::

    http://localhost:8888/unsafe/filters:round_corner(20,255,255,255)/https%3A%2F%2Fgithub.com%2Fthumbor%2Fthumbor%2Fraw%2Fmaster%2Fexample.jpg

.. image:: images/rounded1.jpg
    :alt: Picture after rounded corners

::

    http://localhost:8888/unsafe/filters:round_corner(20|40,0,0,0)/https%3A%2F%2Fgithub.com%2Fthumbor%2Fthumbor%2Fraw%2Fmaster%2Fexample.jpg

.. image:: images/rounded2.jpg
    :alt: Picture after rounded corners

::

    http://localhost:8888/unsafe/filters:round_corner(30,0,0,0,1)/https%3A%2F%2Fgithub.com%2Fthumbor%2Fthumbor%2Fraw%2Fmaster%2Fexample.jpg

.. image:: images/rounded3.jpg
    :alt: Picture after rounded corners (transparent)