Many useful, special-purpose color maps (lookup tables) have been created for Adobe Photoshop. This tool is intended to extract information from these files and make these color maps available in matplotlib for use as part of a free and open-source toolchain.
The conversion tool presently supports colors specified in RGB, HSV, and CMYK, and will automatically convert to RGB format for matplotlib internal use.
This tool has been tested with python 2.7. Required dependencies can be installed via the following command:
pip install -r requirements.txt
The basic reader can be called from other programs, or run directly to output a textual representation of data in the gradient file:
python grd_reader.py input_filename.grd
To parse the file and generate a python-importable matplotlib-format color map (with extension .py):
python matplotlib_converter.py input_filename.grd
And to parse the file and generate a list of colorstops (suitable for use with HTML5 canvas gradients) to a new file (with extension .js):
python jsgradient_converter.py
In the future these scripts will be consolidated to a single tool.
This tool was originally designed for a specific purpose (extraction of the ORI "Advanced forensic actions" lookup tables for use with matplotlib).
As such, it is heavily tailored towards the creation of Linear Segmented Color Maps with evenly spaced colors. Discontinuous gradients, opacity, and the LAB color scheme are among the features not presently supported. Issue reports and pull requests are welcome.
Valek Filippov and the RE-lab team decoded the .grd file format and provided an initial parser implementation that this tool relies heavily on.