openlut/README.rst

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openlut - Open-source tools for practical color management.
===========================================================
\*\*Main development happens at
https://git.sofusrose.com/so-rose/openlut - take a look!
What is it?
-----------
openlut is, at its core, a transform-focused color management library,
accessible from **Python 3.5+**. It's built on my own color pipeline
needs, which includes managing Lookup Tables, Gamma/Gamut
functions/matrices, applying color transformations, etc. .
openlut is also a practical tool. Included soon will be a command line
utility letting you perform complex color transformations from the
comfort of your console. Included already is an OpenGL image viewer,
which might grow in the future to play sequences.
I wanted it to cover this niche simply and consistently, with batteries
included (a library of gamma functions and color gamut matrices). Color
management doesn't have to be so difficult!
What About OpenColorIO? Why does this exist?
--------------------------------------------
OpenColorIO does amazing work - but mostly in the context of large
applications, not-simple config files, and self-defined color space
(with the full range of int/float bit depth specifics, etc.)
openlut is all about images and the transforms on images. Everything
happens in (0, 1) float space. Large emphasis is placed on managing the
tools themselves as well - composing matrices, resizing LUTs, defining
new gamma functions, etc. .
In many ways, OCIO is a system stringing basic operations together. I'd
be perfectly plausible to write an OCIO alternative with openlut in the
backend.
Documentation
-------------
Docs can be found at https://sofusrose.com/openlut. They're a work in
progress for now (ColMap is 100% documented).
Installation
------------
First: **Ensure you have dependencies!!!** The pip command will break
without them.
Simply use pip: ``pip3 install openlut`` (pip3 denotes that you must use
a Python 3 version of pip). Keep in mind, there are some external
dependencies: \* **Python 3.5**: This is Python; you need Python. \*
**gcc**: This is needed to compile the C++ extensions. \*
**imagemagick**: For all file IO. It's not like I was gonna write that
myself :) .
*If it's breaking, try running ``pip3 install -U pip setuptools``.
Sometimes they are out of date.* *Linux: You make need to use ``sudo``
before the command. Ignore the AssertionError when building the wheel;
it doesn't affect anything.*
Installing Dependencies
-----------------------
Not Difficult, I promise!
On Debian/Ubuntu:
``sudo apt-get install python3-pip gcc libmagickwand-dev``
On Mac: ``brew install python3 gcc imagemagick`` \* You will need
Homebrew ( copy/paste a command from http://brew.sh/ to install ) and
XCode Command Line Tools for gcc (it should prompt you to install this).
\* If this doesn't install pip, run
``brew install python3; curl https://bootstrap.pypa.io/get-pip.py | python3``
On Other: You need **python 3.5**, pip, a newer version (must support
C++14) of **gcc**.
Basic Library Usage
-------------------
To represent images, use a **ColMap** object. This handles IO to/from
all ImageMagick supported formats (**including EXR and DPX**), as well
as storing the image data.
Use any child of the **Transform** class to do a color transform on a
ColMap, using ColMap's ``apply(Transform)`` method.
The **Transform** objects themselves have plenty of features - like LUT,
with ``open()``, ``save()``, and ``resize()`` methods, or TransMat with
auto-combining input matrices, or automatic spline-based interpolation
of very small 1D LUTs - to make them helpful in and of themselves!
Take a look at the test code under tests for examples.