spectra/lib/python3.12/site-packages/PIL/XVThumbImagePlugin.py
2024-11-05 13:55:44 -05:00

86 lines
2.1 KiB
Python

#
# The Python Imaging Library.
# $Id$
#
# XV Thumbnail file handler by Charles E. "Gene" Cash
# (gcash@magicnet.net)
#
# see xvcolor.c and xvbrowse.c in the sources to John Bradley's XV,
# available from ftp://ftp.cis.upenn.edu/pub/xv/
#
# history:
# 98-08-15 cec created (b/w only)
# 98-12-09 cec added color palette
# 98-12-28 fl added to PIL (with only a few very minor modifications)
#
# To do:
# FIXME: make save work (this requires quantization support)
#
from __future__ import annotations
from . import Image, ImageFile, ImagePalette
from ._binary import o8
_MAGIC = b"P7 332"
# standard color palette for thumbnails (RGB332)
PALETTE = b""
for r in range(8):
for g in range(8):
for b in range(4):
PALETTE = PALETTE + (
o8((r * 255) // 7) + o8((g * 255) // 7) + o8((b * 255) // 3)
)
def _accept(prefix: bytes) -> bool:
return prefix[:6] == _MAGIC
##
# Image plugin for XV thumbnail images.
class XVThumbImageFile(ImageFile.ImageFile):
format = "XVThumb"
format_description = "XV thumbnail image"
def _open(self) -> None:
# check magic
assert self.fp is not None
if not _accept(self.fp.read(6)):
msg = "not an XV thumbnail file"
raise SyntaxError(msg)
# Skip to beginning of next line
self.fp.readline()
# skip info comments
while True:
s = self.fp.readline()
if not s:
msg = "Unexpected EOF reading XV thumbnail file"
raise SyntaxError(msg)
if s[0] != 35: # ie. when not a comment: '#'
break
# parse header line (already read)
s = s.strip().split()
self._mode = "P"
self._size = int(s[0]), int(s[1])
self.palette = ImagePalette.raw("RGB", PALETTE)
self.tile = [
ImageFile._Tile(
"raw", (0, 0) + self.size, self.fp.tell(), (self.mode, 0, 1)
)
]
# --------------------------------------------------------------------
Image.register_open(XVThumbImageFile.format, XVThumbImageFile, _accept)