public-espnow2mqtt/002-espnow2mqtt_sender/lib/TFT_eSPI/Tools/bmp2array4bit

bmp2array4bit

bmp2array4bit.py reads a bmp file, and creates C (or C++) code that contains two arrays for adding images to four-bit sprites. See Sprite_image_4bit for an example.

It is loosely based on Spark Fun's bmp2array script, https://github.com/sparkfun/BMPtoArray/blob/master/bmp2array.py. The bmp file format is documented in https://en.wikipedia.org/wiki/BMP_file_format.

You'll need python 3.6 (the original uses Python 2.7)

usage: python bmp2array4bit.py [-v] star.bmp [-o myfile.c]

Create the bmp file in Gimp (www.gimp.org) from any image as follows:

• Remove the alpha channel (if it has one) Layer -> Transparency -> Remove Alpha Channel
• Set the mode to indexed. Image -> Mode -> Indexed...
• Select Generate optimum palette with 16 colors (max)
• Export the file with a .bmp extension. Do NOT select options:
  • Run-Length Encoded
  • Compatibility Options: "Do not write color space information"
  • There are no Advanced Options available with these settings

(There are other tools that will produce bmp files, and these should work provided you don't use run-length encoding or other advanced features).

The first array produced is the palette for the image. The second is the image itself.