ender3_lcd_bootscreen_generator.py

"""
this script takes `image.png` as input, 
resize it to 63pix height, 
then binarize it, 
to create `_Bootscreen.h` file

`_Bootscreen.h` can be used as part of https://github.com/MarlinFirmware/Marlin

I used it with: https://github.com/bigtreetech/BIGTREETECH-SKR-mini-E3/tree/master/firmware/V2.0/Marlin-2.0.7.2-SKR-mini-E3-V2.0

"""


import numpy as np
import skimage.io as skio
import matplotlib.pyplot as plt
from skimage.color import rgb2gray, rgba2rgb

from skimage.filters import threshold_li, threshold_otsu, threshold_triangle
from skimage.transform import rescale, resize, downscale_local_mean

default_strings = """
#pragma once

#define CONFIG_EXAMPLES_DIR "Creality/Ender-3 Pro/BigTreeTech SKR Mini E3 2.0"
#define CUSTOM_BOOTSCREEN_TIMEOUT 2000
#define CUSTOM_BOOTSCREEN_INVERTED
"""



if __name__ == "__main__":
	lcd_width = 127
	lcd_height = 63


	# open input image
	image = skio.imread("image.png")
	# to grayscale

	if image.shape[-1] == 4:
		image = rgba2rgb(image)
	image = rgb2gray(image)
	im_height, im_width = image.shape[:2]
	scale = min(lcd_width / im_width, lcd_height / im_height)


	plt.imshow(image, cmap=plt.cm.gray)
	plt.show()
	image = rescale(image, scale, anti_aliasing=False)
	CUSTOM_BOOTSCREEN_BMPWIDTH = image.shape[1]
	CUSTOM_BOOTSCREEN_BMPHEIGHT = image.shape[0]

	plt.imshow(image, cmap=plt.cm.gray)
	plt.show()
	thresh = threshold_otsu(image)
	image = image > thresh

	plt.imshow(image, cmap=plt.cm.gray)
	plt.show()

	with open('_Bootscreen.h', 'w') as f:
		f.write(default_strings)
		f.write(f"#define CUSTOM_BOOTSCREEN_BMPWIDTH {CUSTOM_BOOTSCREEN_BMPWIDTH}\n")
		f.write(f"#define CUSTOM_BOOTSCREEN_BMPHEIGHT {CUSTOM_BOOTSCREEN_BMPHEIGHT}\n")

		f.write("const unsigned char custom_start_bmp[] PROGMEM = {\n")
		for image_line in image:
			mod = 8 - image_line.shape[0] % 8
			b = np.array([True] * mod)
			image_line = np.concatenate([image_line, b])
			image_lines = np.split(image_line, image_line.shape[0] // 8)
			for char in image_lines:
				char = char.astype(np.uint8).tolist()
				char = "".join(map(str, char))
				char = f"B{char}, "
				f.write(char)
			f.write('\n')
		f.write("};\n")