python-lcms2 0.1.0

Python binding for LittleCMS2 library

python-lcms2

Python binding for the LittleCMS2 color management library.

Installation

pip install python-lcms2

Pre-built wheels are available on PyPI for Windows (x86-64) and Linux (x86-64) on Python 3.10 and later. For other platforms, see Building from source.

Usage

import lcms2

Profiles

A Profile can be created from a built-in name, a file on disk, or raw bytes in memory:

srgb    = lcms2.Profile("sRGB")
prophoto = lcms2.Profile("ProPhoto RGB")
from_file = lcms2.Profile(filename="CMYK.icm")

with open("CMYK.icm", "rb") as f:
    from_bytes = lcms2.Profile(buffer=f.read())

Built-in profiles provided by LittleCMS: sRGB, Lab, XYZ.

Additional built-in RGB profiles: Adobe RGB (1998), Apple RGB, Best RGB, Beta RGB, Bruce RGB, CIE RGB, ColorMatch RGB, Don RGB 4, ECI RGB v2, Ekta Space PS5, NTSC RGB, PAL/SECAM RGB, ProPhoto RGB, SMPTE-C RGB, _sRGB, Wide Gamut RGB.

Transforms

A Transform converts pixel data from one profile and format to another:

lab  = lcms2.Profile("Lab")
srgb = lcms2.Profile("sRGB")

transform = lcms2.Transform(lab, "Lab_DBL", srgb, "RGB_16")

The constructor signature is:

Transform(src_profile, src_format, dst_profile, dst_format, intent="PERCEPTUAL", flags="NONE")

All supported format strings:

lcms2.DATA_TYPES.keys()

Rendering intents (lcms2.INTENT): PERCEPTUAL, RELATIVE_COLORIMETRIC, SATURATION, ABSOLUTE_COLORIMETRIC.

Flags (lcms2.FLAG) can be combined with commas, spaces, semicolons, or |:

transform = lcms2.Transform(lab, "Lab_DBL", srgb, "RGB_16",
                            intent="PERCEPTUAL",
                            flags="GAMUTCHECK,SOFTPROOFING")

Applying a transform

Transform.apply accepts a NumPy array or any array-compatible object and returns a transformed NumPy array:

result = transform.apply([50.0, 0.0, 0.0])   # L*a*b* neutral grey

The input type must match the source format declared at construction time. When passing lists or other convertibles, the data is cast automatically where possible.

Building from source

Clone the repository with its submodules:

git clone --recurse-submodules https://github.com/wzjoriv/python-lcms2.git
cd python-lcms2

Install the build tool if needed:

pip install build --upgrade

Build a wheel:

python -m build --wheel

The wheel is written to dist/. Install it with:

pip install dist/python_lcms2*.whl

Windows path detection (Windows SDK include and library directories) is handled automatically via the registry in setup.py. If the build fails on your Windows installation, the paths may need to be adjusted manually.

For bugs, questions, and feature requests use GitHub Issues.

Acknowledgements

This project is a continuation of work by prior maintainers. The lineage of the repository is: sk1-project → RomanKosobrodov → wzjoriv.