Little python script to convert images to sprites ;-) (LowRes NX)

Greenpilloz 2020-11-04 16:25

Hi there, heres a little piece of code to convert png images into sprites for LowRes NX:



#!/usr/bin/env python3
"""
Little script to convert pngs (or any image type) to tilemap
in the lowres nx format

If the image is too long
we produce many character sets
in several ROMS

If the image is wider than 16*8, it will be cropped

We cut 8x8 images and convert them to 4 colors

Made by @Greenpilloz, no licence (Do what you want)

"""
from PIL import Image
import sys


def convert(infile = 'tileset_16x16_Jerom_CC-BY-SA-3.0.png'):
    img = Image.open(infile)
    i=0
    j=0
    MAXROMS = 7
    ROM=2
    lines = ['#2:MAIN CHARACTERS']
    for j in range(0, img.size[1], 8):

        # if the image is too long
        # we produce many character sets
        # in several ROMS
        if j>0 and j % (16*8) == 0:
            ROM += 1
            lines.append('\n\n#'+str(ROM)+':OTHER CHARS '+str(ROM-2))


        # If the image is wider than 16*8, it will be cropped
        for i in range(0, min(16*8,img.size[0]), 8):

            # We cut a 8x8 image and convert it to 4 colors
            im = img.crop((i, j, i+8, j+8))
            result = im.convert('P', palette=Image.ADAPTIVE, colors=4)
            pix = result.load()

            ss0=''
            ss1=''
            for y in range(0, 8):
                s0 = ''
                s1 = ''
                for x in reversed(range(0, 8)):
                    b0 = bin(256+round((pix[x,y])))[-1]
                    b1 = bin(256+round((pix[x,y])))[-2]
                    #print(pix[i,j], b1)
                    s0=b0+s0
                    s1=b1+s1
                s0 = ("%02X" % int(s0,2))
                s1 = ("%02X" % int(s1,2))
                ss0=ss0+s0
                ss1=ss1+s1

                if len(ss0)==16:
                    lines.append(ss0+ss1)
                    ss0=''
                    ss1=''
        if ROM >= MAXROMS:
            break

    # writting to a files
    with open('out.nx', 'w') as f:
        f.writelines('\n'.join(lines))

if __name__ == '__main__':
    if len(sys.argv) > 1:
        for file in sys.argv[1:]:
            convert(file)
    else:
        convert()

To make it work you need:

python 3.X (any version)
the PIL library (to install do: pip install pillow)
Copy the script to a file (e.g. convert2nx.py)
Authorise the script to be executed (type chmod ugo+x convert2nx.png in a terminal on mac or linux)
And then you can call it from a terminal like such:
```
./convert2nx.py myimage.png
```

I did a test with the file attach in the screenshot, and that looks prety promising. This image was taken from [https://opengameart.org/content/16x16-fantasy-tileset]

Enjoy ;-)

out.nx | Open in app

2020-11-04 16:25