openmedialibrary_platform/Darwin/lib/python2.7/site-packages/PIL/PsdImagePlugin.py
2014-05-16 01:20:41 +02:00

291 lines
7.1 KiB
Python

#
# The Python Imaging Library
# $Id$
#
# Adobe PSD 2.5/3.0 file handling
#
# History:
# 1995-09-01 fl Created
# 1997-01-03 fl Read most PSD images
# 1997-01-18 fl Fixed P and CMYK support
# 2001-10-21 fl Added seek/tell support (for layers)
#
# Copyright (c) 1997-2001 by Secret Labs AB.
# Copyright (c) 1995-2001 by Fredrik Lundh
#
# See the README file for information on usage and redistribution.
#
__version__ = "0.4"
import Image, ImageFile, ImagePalette
MODES = {
# (photoshop mode, bits) -> (pil mode, required channels)
(0, 1): ("1", 1),
(0, 8): ("L", 1),
(1, 8): ("L", 1),
(2, 8): ("P", 1),
(3, 8): ("RGB", 3),
(4, 8): ("CMYK", 4),
(7, 8): ("L", 1), # FIXME: multilayer
(8, 8): ("L", 1), # duotone
(9, 8): ("LAB", 3)
}
#
# helpers
def i16(c):
return ord(c[1]) + (ord(c[0])<<8)
def i32(c):
return ord(c[3]) + (ord(c[2])<<8) + (ord(c[1])<<16) + (ord(c[0])<<24)
# --------------------------------------------------------------------.
# read PSD images
def _accept(prefix):
return prefix[:4] == "8BPS"
##
# Image plugin for Photoshop images.
class PsdImageFile(ImageFile.ImageFile):
format = "PSD"
format_description = "Adobe Photoshop"
def _open(self):
read = self.fp.read
#
# header
s = read(26)
if s[:4] != "8BPS" or i16(s[4:]) != 1:
raise SyntaxError, "not a PSD file"
psd_bits = i16(s[22:])
psd_channels = i16(s[12:])
psd_mode = i16(s[24:])
mode, channels = MODES[(psd_mode, psd_bits)]
if channels > psd_channels:
raise IOError, "not enough channels"
self.mode = mode
self.size = i32(s[18:]), i32(s[14:])
#
# color mode data
size = i32(read(4))
if size:
data = read(size)
if mode == "P" and size == 768:
self.palette = ImagePalette.raw("RGB;L", data)
#
# image resources
self.resources = []
size = i32(read(4))
if size:
# load resources
end = self.fp.tell() + size
while self.fp.tell() < end:
signature = read(4)
id = i16(read(2))
name = read(ord(read(1)))
if not (len(name) & 1):
read(1) # padding
data = read(i32(read(4)))
if (len(data) & 1):
read(1) # padding
self.resources.append((id, name, data))
if id == 1039: # ICC profile
self.info["icc_profile"] = data
#
# layer and mask information
self.layers = []
size = i32(read(4))
if size:
end = self.fp.tell() + size
size = i32(read(4))
if size:
self.layers = _layerinfo(self.fp)
self.fp.seek(end)
#
# image descriptor
self.tile = _maketile(self.fp, mode, (0, 0) + self.size, channels)
# keep the file open
self._fp = self.fp
self.frame = 0
def seek(self, layer):
# seek to given layer (1..max)
if layer == self.frame:
return
try:
if layer <= 0:
raise IndexError
name, mode, bbox, tile = self.layers[layer-1]
self.mode = mode
self.tile = tile
self.frame = layer
self.fp = self._fp
return name, bbox
except IndexError:
raise EOFError, "no such layer"
def tell(self):
# return layer number (0=image, 1..max=layers)
return self.frame
def load_prepare(self):
# create image memory if necessary
if not self.im or\
self.im.mode != self.mode or self.im.size != self.size:
self.im = Image.core.fill(self.mode, self.size, 0)
# create palette (optional)
if self.mode == "P":
Image.Image.load(self)
def _layerinfo(file):
# read layerinfo block
layers = []
read = file.read
for i in range(abs(i16(read(2)))):
# bounding box
y0 = i32(read(4)); x0 = i32(read(4))
y1 = i32(read(4)); x1 = i32(read(4))
# image info
info = []
mode = []
for i in range(i16(read(2))):
type = i16(read(2))
if type == 65535:
m = "A"
else:
m = "RGB"[type]
mode.append(m)
size = i32(read(4))
info.append((m, size))
# figure out the image mode
mode.sort()
if mode == ["R"]:
mode = "L"
elif mode == ["B", "G", "R"]:
mode = "RGB"
elif mode == ["A", "B", "G", "R"]:
mode = "RGBA"
else:
mode = None # unknown
# skip over blend flags and extra information
filler = read(12)
name = ""
size = i32(read(4))
combined = 0
if size:
length = i32(read(4))
if length:
mask_y = i32(read(4)); mask_x = i32(read(4))
mask_h = i32(read(4)) - mask_y; mask_w = i32(read(4)) - mask_x
file.seek(length - 16, 1)
combined += length + 4
length = i32(read(4))
if length:
file.seek(length, 1)
combined += length + 4
length = ord(read(1))
if length:
name = read(length)
combined += length + 1
file.seek(size - combined, 1)
layers.append((name, mode, (x0, y0, x1, y1)))
# get tiles
i = 0
for name, mode, bbox in layers:
tile = []
for m in mode:
t = _maketile(file, m, bbox, 1)
if t:
tile.extend(t)
layers[i] = name, mode, bbox, tile
i = i + 1
return layers
def _maketile(file, mode, bbox, channels):
tile = None
read = file.read
compression = i16(read(2))
xsize = bbox[2] - bbox[0]
ysize = bbox[3] - bbox[1]
offset = file.tell()
if compression == 0:
#
# raw compression
tile = []
for channel in range(channels):
layer = mode[channel]
if mode == "CMYK":
layer = layer + ";I"
tile.append(("raw", bbox, offset, layer))
offset = offset + xsize*ysize
elif compression == 1:
#
# packbits compression
i = 0
tile = []
bytecount = read(channels * ysize * 2)
offset = file.tell()
for channel in range(channels):
layer = mode[channel]
if mode == "CMYK":
layer = layer + ";I"
tile.append(
("packbits", bbox, offset, layer)
)
for y in range(ysize):
offset = offset + i16(bytecount[i:i+2])
i = i + 2
file.seek(offset)
if offset & 1:
read(1) # padding
return tile
# --------------------------------------------------------------------
# registry
Image.register_open("PSD", PsdImageFile, _accept)
Image.register_extension("PSD", ".psd")