Pillow/src/PIL/GbrImagePlugin.py

101 lines
2.7 KiB
Python

#
# The Python Imaging Library
#
# load a GIMP brush file
#
# History:
# 96-03-14 fl Created
# 16-01-08 es Version 2
#
# Copyright (c) Secret Labs AB 1997.
# Copyright (c) Fredrik Lundh 1996.
# Copyright (c) Eric Soroos 2016.
#
# See the README file for information on usage and redistribution.
#
#
# See https://github.com/GNOME/gimp/blob/mainline/devel-docs/gbr.txt for
# format documentation.
#
# This code Interprets version 1 and 2 .gbr files.
# Version 1 files are obsolete, and should not be used for new
# brushes.
# Version 2 files are saved by GIMP v2.8 (at least)
# Version 3 files have a format specifier of 18 for 16bit floats in
# the color depth field. This is currently unsupported by Pillow.
from . import Image, ImageFile
from ._binary import i32be as i32
def _accept(prefix):
return len(prefix) >= 8 and i32(prefix, 0) >= 20 and i32(prefix, 4) in (1, 2)
##
# Image plugin for the GIMP brush format.
class GbrImageFile(ImageFile.ImageFile):
format = "GBR"
format_description = "GIMP brush file"
def _open(self):
header_size = i32(self.fp.read(4))
version = i32(self.fp.read(4))
if header_size < 20:
raise SyntaxError("not a GIMP brush")
if version not in (1, 2):
raise SyntaxError(f"Unsupported GIMP brush version: {version}")
width = i32(self.fp.read(4))
height = i32(self.fp.read(4))
color_depth = i32(self.fp.read(4))
if width <= 0 or height <= 0:
raise SyntaxError("not a GIMP brush")
if color_depth not in (1, 4):
raise SyntaxError(f"Unsupported GIMP brush color depth: {color_depth}")
if version == 1:
comment_length = header_size - 20
else:
comment_length = header_size - 28
magic_number = self.fp.read(4)
if magic_number != b"GIMP":
raise SyntaxError("not a GIMP brush, bad magic number")
self.info["spacing"] = i32(self.fp.read(4))
comment = self.fp.read(comment_length)[:-1]
if color_depth == 1:
self.mode = "L"
else:
self.mode = "RGBA"
self._size = width, height
self.info["comment"] = comment
# Image might not be small
Image._decompression_bomb_check(self.size)
# Data is an uncompressed block of w * h * bytes/pixel
self._data_size = width * height * color_depth
def load(self):
if self.im:
# Already loaded
return
self.im = Image.core.new(self.mode, self.size)
self.frombytes(self.fp.read(self._data_size))
#
# registry
Image.register_open(GbrImageFile.format, GbrImageFile, _accept)
Image.register_extension(GbrImageFile.format, ".gbr")