Python package colorscale

This package was written to facilitate working with 'false color'. Many scientific fields work with image files to visualize two-dimensional scalar data. The raw data can then be represented as a grayscale image. For different reasons, representing these data in false color can be useful. This package helps to convert grayscale images to 'false color'. On the other hand, quite often it is desirable to have access to the original values of a false color plot. If the color scale (or 'color map') is known and it is bijective (a reversible one to one mapping), the original gray scale image can be recovered from the false color image using this tool, too.

Installation

pip install colorscale

Usage

After installing, two command line tools will be available:

• to_color_scale and
• to_gray_scale.

Start them with the --help flag to learn how to use them:

$ to_color_scale --help
usage: to_color_scale [-h] -s {tillscale} [-b {pil,cv2}] IMAGEFILE

Convert an image saved as false color to grayscale

positional arguments:
  IMAGEFILE             The image to convert

optional arguments:
  -h, --help            show this help message and exit
  -s {tillscale}, --colorscale {tillscale}
                        Desired color scale
  -b {pil,cv2}, --backend {pil,cv2}

and

$ to_gray_scale --help
usage: to_gray_scale [-h] -s COLORSCALE IMAGEFILE

Convert an image saved as false color to grayscale

positional arguments:
  IMAGEFILE             The image to convert

optional arguments:
  -h, --help            show this help message and exit
  -s COLORSCALE, --colorscale COLORSCALE {tillscale}
                        Desired color scale

ToDo

It is desirable (and on the ToDo list) to make this package work with the colormaps built into matplotlib. Here's a list of the relevant matplotlib documentation pages:

• List of matplotlib colormaps
• Builtin colormaps module matplotlib.cm
• base class matplotlib.colors.Colormap
• Colormaps tutorial (in-depth discussion about colormaps, including colorblind-friendliness)

Resources

• Package in Python Package Index (PyPI): https://pypi.org/project/colorscale/
• Package on Github: https://github.com/pklaus/python_colorscale

Author

• Philipp Klaus
  philipp.l.klaus@web.de