https://github.com/cedargrovestudios/circuitpython_palettefilter

A CircuitPython helper class for replacing color index values in a displayio.Palette object.
https://github.com/cedargrovestudios/circuitpython_palettefilter

circuitpython circuitpython-community-bundle greenscreen palette-color-replacement palette-filter

Last synced: about 1 month ago
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A CircuitPython helper class for replacing color index values in a displayio.Palette object.

• Host: GitHub
• URL: https://github.com/cedargrovestudios/circuitpython_palettefilter
• Owner: CedarGroveStudios
• License: mit
• Created: 2022-09-24T00:20:37.000Z (about 2 years ago)
• Default Branch: main
• Last Pushed: 2023-11-02T03:29:33.000Z (about 1 year ago)
• Last Synced: 2023-11-02T04:25:30.402Z (about 1 year ago)
• Topics: circuitpython, circuitpython-community-bundle, greenscreen, palette-color-replacement, palette-filter
• Language: Python
• Homepage:
• Size: 928 KB
• Stars: 1
• Watchers: 1
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.rst
  • License: LICENSE
  • Code of conduct: CODE_OF_CONDUCT.md

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README

        
Introduction

============

.. image:: https://img.shields.io/discord/327254708534116352.svg

    :target: https://adafru.it/discord

    :alt: Discord

.. image:: https://github.com/CedarGroveStudios/CircuitPython_PaletteFilter/workflows/Build%20CI/badge.svg

    :target: https://github.com/CedarGroveStudios/CircuitPython_PaletteFilter/actions

    :alt: Build Status

.. image:: https://img.shields.io/badge/code%20style-black-000000.svg

    :target: https://github.com/psf/black

    :alt: Code Style: Black

PaletteFilter is a CircuitPython helper class for replacing color index values

in a `displayio.Palette` object. A target color along with a tolerance parameter

determine the range of color values to be replaced. The class creates a new

palette object with the changes. The replacement color value (or `None` for

transparency) is substituted for the original palette entry and placed into the

new palette object, `PaletteFilter.palette`.

The filter uses a linear Euclidean comparison incorporating vision perception

('redmean') approximation to test palette color values with the specified

target color. https://en.wikipedia.org/wiki/Color_difference

For comparing a single color value, use the

`cedargrove_palettefilter.compare_colors()` helper function.

Dependencies

=============

This driver depends on:

* `Adafruit CircuitPython `_

Please ensure all dependencies are available on the CircuitPython filesystem.

This is easily achieved by downloading

`the Adafruit library and driver bundle `_

or individual libraries can be installed using

`circup `_.

Installing to a Connected CircuitPython Device with Circup

==========================================================

Make sure that you have ``circup`` installed in your Python environment.

Install it with the following command if necessary:

.. code-block:: shell

    pip3 install circup

With ``circup`` installed and your CircuitPython device connected use the

following command to install:

.. code-block:: shell

    circup install cedargrove_palettefilter

Or the following command to update an existing version:

.. code-block:: shell

    circup update

Usage Example

=============

.. code-block:: py

    import displayio

    from cedargrove_palettefilter import PaletteFilter

    # Define the transparent color and tolerance values

    TARGET_COLOR = 0x080808

    FILL_COLOR = None

    TOLERANCE = 4

    # Make a displayio palette and set value(s) to transparent

    SOURCE_COLORS = [

        0x000000,

        0x010101,

        0x020202,

        0x030303,

        0x040404,

        0x050505,

        0x060606,

        0x070707,

        0x080808,

        0x090909,

    ]

    SOURCE_PALETTE = displayio.Palette(len(SOURCE_COLORS))

    for index, color in enumerate(SOURCE_COLORS):

        SOURCE_PALETTE[index] = SOURCE_COLORS[index]

    # Set a source palette value to transparent

    SOURCE_PALETTE.make_transparent(3)

    # Instantiate paletteFilter

    filter = PaletteFilter(SOURCE_PALETTE, TARGET_COLOR, FILL_COLOR, TOLERANCE)

    print(f"target_color: {hex(filter.target_color)}")

    print("------")

    print("source palette:")

    print("index, color, transparency")

    for index, color in enumerate(SOURCE_PALETTE):

        print(index, hex(color), SOURCE_PALETTE.is_transparent(index))

    print("------")

    print("new palette:")

    print("index, color, transparency")

    for index, color in enumerate(filter.palette):

        print(index, hex(color), filter.palette.is_transparent(index))

    while True:

        pass

Documentation

=============

API documentation for this library can be found in `PaletteFilter_API `_.

.. image:: https://github.com/CedarGroveStudios/CircuitPython_PaletteFilter/blob/main/media/flying_lars_test.png

For information on building library documentation, please check out

`this guide `_.

Contributing

============

Contributions are welcome! Please read our `Code of Conduct

`_

before contributing to help this project stay welcoming.