#
# 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.
#
__version__ = "0.3"
import Image, ImageFile, ImagePalette
#
# --------------------------------------------------------------------
# Read RGA file
def i16(c):
return ord(c[0]) + (ord(c[1])<<8)
def i32(c):
return ord(c[0]) + (ord(c[1])<<8) + (ord(c[2])<<16) + (ord(c[3])<<24)
MODES = {
# map imagetype/depth to rawmode
(1, 8): "P",
(3, 1): "1",
(3, 8): "L",
(2, 16): "BGR;5",
(2, 24): "BGR",
(2, 32): "BGRA",
}
def _accept(prefix):
return prefix[0] == "\0"
##
# Image plugin for Targa files.
class TgaImageFile(ImageFile.ImageFile):
format = "TGA"
format_description = "Targa"
def _open(self):
# process header
s = self.fp.read(18)
id = ord(s[0])
colormaptype = ord(s[1])
imagetype = ord(s[2])
depth = ord(s[16])
flags = ord(s[17])
self.size = i16(s[12:]), i16(s[14:])
# validate header fields
if id != 0 or colormaptype not in (0, 1) or\
self.size[0] <= 0 or self.size[1] <= 0 or\
depth not in (1, 8, 16, 24, 32):
raise SyntaxError, "not a TGA file"
# image mode
if imagetype in (3, 11):
self.mode = "L"
if depth == 1:
self.mode = "1" # ???
elif imagetype in (1, 9):
self.mode = "P"
elif imagetype in (2, 10):
self.mode = "RGB"
if depth == 32:
self.mode = "RGBA"
else:
raise SyntaxError, "unknown TGA mode"
# orientation
orientation = flags & 0x30
if orientation == 0x20:
orientation = 1
elif not orientation:
orientation = -1
else:
raise SyntaxError, "unknown TGA orientation"
self.info["orientation"] = orientation
if imagetype & 8:
self.info["compression"] = "tga_rle"
if colormaptype:
# read palette
start, size, mapdepth = i16(s[3:]), i16(s[5:]), i16(s[7:])
if mapdepth == 16:
self.palette = ImagePalette.raw("BGR;16",
"\0"*2*start + self.fp.read(2*size))
elif mapdepth == 24:
self.palette = ImagePalette.raw("BGR",
"\0"*3*start + self.fp.read(3*size))
elif mapdepth == 32:
self.palette = ImagePalette.raw("BGRA",
"\0"*4*start + self.fp.read(4*size))
# setup tile descriptor
try:
rawmode = MODES[(imagetype&7, depth)]
if imagetype & 8:
# compressed
self.tile = [("tga_rle", (0, 0)+self.size,
self.fp.tell(), (rawmode, orientation, depth))]
else:
self.tile = [("raw", (0, 0)+self.size,
self.fp.tell(), (rawmode, 0, orientation))]
except KeyError:
pass # cannot decode
#
# --------------------------------------------------------------------
# Write TGA file
def o16(i):
return chr(i&255) + chr(i>>8&255)
def o32(i):
return chr(i&255) + chr(i>>8&255) + chr(i>>16&255) + chr(i>>24&255)
SAVE = {
"1": ("1", 1, 0, 3),
"L": ("L", 8, 0, 3),
"P": ("P", 8, 1, 1),
"RGB": ("BGR", 24, 0, 2),
"RGBA": ("BGRA", 32, 0, 2),
}
def _save(im, fp, filename, check=0):
try:
rawmode, bits, colormaptype, imagetype = SAVE[im.mode]
except KeyError:
raise IOError("cannot write mode %s as TGA" % im.mode)
if check:
return check
if colormaptype:
colormapfirst, colormaplength, colormapentry = 0, 256, 24
else:
colormapfirst, colormaplength, colormapentry = 0, 0, 0
if im.mode == "RGBA":
flags = 8
else:
flags = 0
orientation = im.info.get("orientation", -1)
if orientation > 0:
flags = flags | 0x20
fp.write("\000" +
chr(colormaptype) +
chr(imagetype) +
o16(colormapfirst) +
o16(colormaplength) +
chr(colormapentry) +
o16(0) +
o16(0) +
o16(im.size[0]) +
o16(im.size[1]) +
chr(bits) +
chr(flags))
if colormaptype:
fp.write(im.im.getpalette("RGB", "BGR"))
ImageFile._save(im, fp, [("raw", (0,0)+im.size, 0, (rawmode, 0, orientation))])
#
# --------------------------------------------------------------------
# Registry
Image.register_open("TGA", TgaImageFile, _accept)
Image.register_save("TGA", _save)
Image.register_extension("TGA", ".tga")
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