reMarkable 2 splash.dat converter

main.py

#!/usr/bin/env python3
"""
This script aims at converting an image to the custom format used by Remarkable 2
After running this script, move the output "splash.dat" file to /var/lib/uboot in the rM2 device
I tried this with PNG images but I guess other formats should work too since I use PIL
Syntax: ./main.py <file> [-x xOffset] [-y yOffset]
(-x and -y are the offsets of the image on the screen. If not set, the image will be centered on the screen)
Input images may need to be rotated 90 degrees before converting them
Licence: MPL 2.0
"""

import sys
from PIL import Image, ImageOps
import argparse

TABLET_HEIGHT = 1872
TABLET_WIDTH = 1404

parser = argparse.ArgumentParser()
parser.add_argument("file", help="image to convert", type=str)
parser.add_argument("-x", help="X offset for image", type=int)
parser.add_argument("-y", help="Y offset for image", type=int)
args = parser.parse_args()


if len(sys.argv)==1:
    print("Syntax : "+sys.args[0]+" <image file>")
    exit()


img = Image.open(sys.argv[1], "r")
img = ImageOps.grayscale(img)
d = map(lambda i:round(i/16), img.getdata())

if img.width > TABLET_HEIGHT or img.height > TABLET_WIDTH:
    print("Error: input image dimensions are larger than the tablet dimensions.")
    print(" Hint: you should rotate the image 90 degrees before converting it")
    exit(1)

# If offsets are not set, default to centering the image
if args.x == None:
    args.x = int(TABLET_HEIGHT/2-img.width/2)
if args.y == None:
    args.y = int(TABLET_WIDTH/2-img.height/2)


outf = open("splash.dat", "wb")

def w_header(num):
    outf.write(num.to_bytes(4, "little"))

w_header(args.x)
w_header(args.y)
w_header(img.width)
w_header(img.height)
outf.write(bytearray(d))
outf.close()

print("Convertion finished ! Output file: splash.dat")

I updated the script to indicate that, feel free to try it and give me feedback