Colormaps: available templates

Colormaps can be created either:

• directly in batch mode,

• or in the GUI via the colormap table editor

• or in the GUI tool to extract a colormap from a line drawn on an image

However, for convenience a few colormaps templates are also available.

To list them all

import fractalshades.colors as fscolors
fscolors.cmap_register.keys()

To access one by its name

import fractalshades.colors as fscolors
fscolors.cmap_register["atoll"]

Attached are the auto-generated images of the colormap templates available.

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import os
import sys

if sys.version_info < (3, 9):
# See :
# https://discuss.python.org/t/deprecating-importlib-resources-legacy-api/11386/24
    import importlib_resources
else:
    import importlib.resources as importlib_resources

import numpy as np
import PIL
from PIL import ImageDraw, ImageFont, PngImagePlugin

import fractalshades as fs
import fractalshades.colors as fscolors


def plot_cmap(cmap_identifier, plot_dir, nx=600, ny=40):
    cmap_register = fscolors.cmap_register
    cmap = cmap_register[cmap_identifier]
    B = cmap._output(nx, ny)

    C = np.empty((ny * 2, nx, 3), dtype=np.uint8)
    C [ny:, :, :] = B
    C [:ny, :, :] = 255
    # B[:(ny // 2), :, :] = 255
    im = PIL.Image.fromarray(C)
    draw = ImageDraw.Draw(im)

    fs_resources = importlib_resources.files("fractalshades")
    with importlib_resources.as_file(
        fs_resources / "data" / "GidoleFont" / "Gidole-Regular.ttf"
    ) as font_file:
        font = ImageFont.truetype(str(font_file.resolve()), size=26)

    draw.text((0,0), cmap_identifier, (0, 0, 0), font=font)
    fs.utils.mkdir_p(plot_dir)

    if fs.settings.output_context["doc"]:
        tag_dict = {"Software": "fractalshades " + fs.__version__,
                    "colormap template": cmap_identifier}
        pnginfo = PngImagePlugin.PngInfo()
        for k, v in tag_dict.items():
            pnginfo.add_text(k, str(v))
        fs.settings.add_figure(fs._Pillow_figure(im, pnginfo))

    else:
        im.save(os.path.join(plot_dir, cmap_identifier + ".png"))

def plot_cmaps(plot_dir):
    cmap_register = fscolors.cmap_register
    for cmap_identifier in cmap_register.keys():
        plot_cmap(cmap_identifier, plot_dir)


if __name__ == "__main__":
    # Some magic to get the directory for plotting: with a name that matches
    # the file or a temporary dir if we are building the documentation
    try:
        realpath = os.path.realpath(__file__)
        plot_dir = os.path.splitext(realpath)[0]
        plot_cmaps(plot_dir)
    except NameError:
        import tempfile
        with tempfile.TemporaryDirectory() as plot_dir:
            fs.utils.exec_no_output(plot_cmaps, plot_dir)