FarbfeldImagePlugin.py

"""
Plugin for both encoding and decoding Suckless Farbfeld files
for the PIL library (compression not supported).
"""

from PIL import Image
from PIL.ImageFile import ImageFile
from struct import unpack, pack

class FarbfeldImageFile(ImageFile):
    format             = 'farbfeld'
    format_description = 'Suckless Farbfeld'

    def _open(self):
        if self.fp.read(8) != b'farbfeld':
            raise SyntaxError('not a Farbfeld file!')
        
        self._size = unpack('>II', self.fp.read(8))
        self.mode  = 'RGBA'  # always 32bit color.
        self.tile  = [('raw', (0,0,*self.size), 16, (self.mode,0,1))]

    @staticmethod
    def _save(self, fp, filename):
        self = self.convert('RGBA')

        fp.write(b'farbfeld' + pack('>II', *self.size))
        fp.write(self.tobytes())

Image.register_open('farbfeld', FarbfeldImageFile)
Image.register_save('farbfeld', FarbfeldImageFile._save)

# NOTE: this mimetype is not registered with IANA, asking the author
# 'image/farbfeld' was recommended.
Image.register_extension('farbfeld', '.ff')
Image.register_mime('farbfeld', 'image/farbfeld')