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

265 lines
6.8 KiB
Python

#
# The Python Imaging Library.
# $Id$
#
# TGA file handling
#
# History:
# 95-09-01 fl created (reads 24-bit files only)
# 97-01-04 fl support more TGA versions, including compressed images
# 98-07-04 fl fixed orientation and alpha layer bugs
# 98-09-11 fl fixed orientation for runlength decoder
#
# Copyright (c) Secret Labs AB 1997-98.
# Copyright (c) Fredrik Lundh 1995-97.
#
# See the README file for information on usage and redistribution.
#
from __future__ import annotations
import warnings
from typing import IO
from . import Image, ImageFile, ImagePalette
from ._binary import i16le as i16
from ._binary import o8
from ._binary import o16le as o16
#
# --------------------------------------------------------------------
# Read RGA file
MODES = {
# map imagetype/depth to rawmode
(1, 8): "P",
(3, 1): "1",
(3, 8): "L",
(3, 16): "LA",
(2, 16): "BGRA;15Z",
(2, 24): "BGR",
(2, 32): "BGRA",
}
##
# Image plugin for Targa files.
class TgaImageFile(ImageFile.ImageFile):
format = "TGA"
format_description = "Targa"
def _open(self) -> None:
# process header
assert self.fp is not None
s = self.fp.read(18)
id_len = s[0]
colormaptype = s[1]
imagetype = s[2]
depth = s[16]
flags = s[17]
self._size = i16(s, 12), i16(s, 14)
# validate header fields
if (
colormaptype not in (0, 1)
or self.size[0] <= 0
or self.size[1] <= 0
or depth not in (1, 8, 16, 24, 32)
):
msg = "not a TGA file"
raise SyntaxError(msg)
# image mode
if imagetype in (3, 11):
self._mode = "L"
if depth == 1:
self._mode = "1" # ???
elif depth == 16:
self._mode = "LA"
elif imagetype in (1, 9):
self._mode = "P" if colormaptype else "L"
elif imagetype in (2, 10):
self._mode = "RGB" if depth == 24 else "RGBA"
else:
msg = "unknown TGA mode"
raise SyntaxError(msg)
# orientation
orientation = flags & 0x30
self._flip_horizontally = orientation in [0x10, 0x30]
if orientation in [0x20, 0x30]:
orientation = 1
elif orientation in [0, 0x10]:
orientation = -1
else:
msg = "unknown TGA orientation"
raise SyntaxError(msg)
self.info["orientation"] = orientation
if imagetype & 8:
self.info["compression"] = "tga_rle"
if id_len:
self.info["id_section"] = self.fp.read(id_len)
if colormaptype:
# read palette
start, size, mapdepth = i16(s, 3), i16(s, 5), s[7]
if mapdepth == 16:
self.palette = ImagePalette.raw(
"BGRA;15Z", bytes(2 * start) + self.fp.read(2 * size)
)
self.palette.mode = "RGBA"
elif mapdepth == 24:
self.palette = ImagePalette.raw(
"BGR", bytes(3 * start) + self.fp.read(3 * size)
)
elif mapdepth == 32:
self.palette = ImagePalette.raw(
"BGRA", bytes(4 * start) + self.fp.read(4 * size)
)
else:
msg = "unknown TGA map depth"
raise SyntaxError(msg)
# setup tile descriptor
try:
rawmode = MODES[(imagetype & 7, depth)]
if imagetype & 8:
# compressed
self.tile = [
ImageFile._Tile(
"tga_rle",
(0, 0) + self.size,
self.fp.tell(),
(rawmode, orientation, depth),
)
]
else:
self.tile = [
ImageFile._Tile(
"raw",
(0, 0) + self.size,
self.fp.tell(),
(rawmode, 0, orientation),
)
]
except KeyError:
pass # cannot decode
def load_end(self) -> None:
if self._flip_horizontally:
self.im = self.im.transpose(Image.Transpose.FLIP_LEFT_RIGHT)
#
# --------------------------------------------------------------------
# Write TGA file
SAVE = {
"1": ("1", 1, 0, 3),
"L": ("L", 8, 0, 3),
"LA": ("LA", 16, 0, 3),
"P": ("P", 8, 1, 1),
"RGB": ("BGR", 24, 0, 2),
"RGBA": ("BGRA", 32, 0, 2),
}
def _save(im: Image.Image, fp: IO[bytes], filename: str | bytes) -> None:
try:
rawmode, bits, colormaptype, imagetype = SAVE[im.mode]
except KeyError as e:
msg = f"cannot write mode {im.mode} as TGA"
raise OSError(msg) from e
if "rle" in im.encoderinfo:
rle = im.encoderinfo["rle"]
else:
compression = im.encoderinfo.get("compression", im.info.get("compression"))
rle = compression == "tga_rle"
if rle:
imagetype += 8
id_section = im.encoderinfo.get("id_section", im.info.get("id_section", ""))
id_len = len(id_section)
if id_len > 255:
id_len = 255
id_section = id_section[:255]
warnings.warn("id_section has been trimmed to 255 characters")
if colormaptype:
palette = im.im.getpalette("RGB", "BGR")
colormaplength, colormapentry = len(palette) // 3, 24
else:
colormaplength, colormapentry = 0, 0
if im.mode in ("LA", "RGBA"):
flags = 8
else:
flags = 0
orientation = im.encoderinfo.get("orientation", im.info.get("orientation", -1))
if orientation > 0:
flags = flags | 0x20
fp.write(
o8(id_len)
+ o8(colormaptype)
+ o8(imagetype)
+ o16(0) # colormapfirst
+ o16(colormaplength)
+ o8(colormapentry)
+ o16(0)
+ o16(0)
+ o16(im.size[0])
+ o16(im.size[1])
+ o8(bits)
+ o8(flags)
)
if id_section:
fp.write(id_section)
if colormaptype:
fp.write(palette)
if rle:
ImageFile._save(
im,
fp,
[ImageFile._Tile("tga_rle", (0, 0) + im.size, 0, (rawmode, orientation))],
)
else:
ImageFile._save(
im,
fp,
[ImageFile._Tile("raw", (0, 0) + im.size, 0, (rawmode, 0, orientation))],
)
# write targa version 2 footer
fp.write(b"\000" * 8 + b"TRUEVISION-XFILE." + b"\000")
#
# --------------------------------------------------------------------
# Registry
Image.register_open(TgaImageFile.format, TgaImageFile)
Image.register_save(TgaImageFile.format, _save)
Image.register_extensions(TgaImageFile.format, [".tga", ".icb", ".vda", ".vst"])
Image.register_mime(TgaImageFile.format, "image/x-tga")