PIL.FpxImagePlugin 源代码

#
# THIS IS WORK IN PROGRESS
#
# The Python Imaging Library.
# $Id$
#
# FlashPix support for PIL
#
# History:
# 97-01-25 fl   Created (reads uncompressed RGB images only)
#
# Copyright (c) Secret Labs AB 1997.
# Copyright (c) Fredrik Lundh 1997.
#
# See the README file for information on usage and redistribution.
#


from PIL import Image, ImageFile
from PIL.OleFileIO import i8, i32, MAGIC, OleFileIO

__version__ = "0.1"


# we map from colour field tuples to (mode, rawmode) descriptors
MODES = {
    # opacity
    (0x00007ffe): ("A", "L"),
    # monochrome
    (0x00010000,): ("L", "L"),
    (0x00018000, 0x00017ffe): ("RGBA", "LA"),
    # photo YCC
    (0x00020000, 0x00020001, 0x00020002): ("RGB", "YCC;P"),
    (0x00028000, 0x00028001, 0x00028002, 0x00027ffe): ("RGBA", "YCCA;P"),
    # standard RGB (NIFRGB)
    (0x00030000, 0x00030001, 0x00030002): ("RGB", "RGB"),
    (0x00038000, 0x00038001, 0x00038002, 0x00037ffe): ("RGBA", "RGBA"),
}


#
# --------------------------------------------------------------------

def _accept(prefix):
    return prefix[:8] == MAGIC


##
# Image plugin for the FlashPix images.

[文档]class FpxImageFile(ImageFile.ImageFile): format = "FPX" format_description = "FlashPix" def _open(self): # # read the OLE directory and see if this is a likely # to be a FlashPix file try: self.ole = OleFileIO(self.fp) except IOError: raise SyntaxError("not an FPX file; invalid OLE file") if self.ole.root.clsid != "56616700-C154-11CE-8553-00AA00A1F95B": raise SyntaxError("not an FPX file; bad root CLSID") self._open_index(1) def _open_index(self, index=1): # # get the Image Contents Property Set prop = self.ole.getproperties([ "Data Object Store %06d" % index, "\005Image Contents" ]) # size (highest resolution) self.size = prop[0x1000002], prop[0x1000003] size = max(self.size) i = 1 while size > 64: size = size / 2 i += 1 self.maxid = i - 1 # mode. instead of using a single field for this, flashpix # requires you to specify the mode for each channel in each # resolution subimage, and leaves it to the decoder to make # sure that they all match. for now, we'll cheat and assume # that this is always the case. id = self.maxid << 16 s = prop[0x2000002 | id] colors = [] for i in range(i32(s, 4)): # note: for now, we ignore the "uncalibrated" flag colors.append(i32(s, 8+i*4) & 0x7fffffff) self.mode, self.rawmode = MODES[tuple(colors)] # load JPEG tables, if any self.jpeg = {} for i in range(256): id = 0x3000001 | (i << 16) if id in prop: self.jpeg[i] = prop[id] # print len(self.jpeg), "tables loaded" self._open_subimage(1, self.maxid) def _open_subimage(self, index=1, subimage=0): # # setup tile descriptors for a given subimage stream = [ "Data Object Store %06d" % index, "Resolution %04d" % subimage, "Subimage 0000 Header" ] fp = self.ole.openstream(stream) # skip prefix fp.read(28) # header stream s = fp.read(36) size = i32(s, 4), i32(s, 8) # tilecount = i32(s, 12) tilesize = i32(s, 16), i32(s, 20) # channels = i32(s, 24) offset = i32(s, 28) length = i32(s, 32) # print size, self.mode, self.rawmode if size != self.size: raise IOError("subimage mismatch") # get tile descriptors fp.seek(28 + offset) s = fp.read(i32(s, 12) * length) x = y = 0 xsize, ysize = size xtile, ytile = tilesize self.tile = [] for i in range(0, len(s), length): compression = i32(s, i+8) if compression == 0: self.tile.append(("raw", (x, y, x+xtile, y+ytile), i32(s, i) + 28, (self.rawmode))) elif compression == 1: # FIXME: the fill decoder is not implemented self.tile.append(("fill", (x, y, x+xtile, y+ytile), i32(s, i) + 28, (self.rawmode, s[12:16]))) elif compression == 2: internal_color_conversion = i8(s[14]) jpeg_tables = i8(s[15]) rawmode = self.rawmode if internal_color_conversion: # The image is stored as usual (usually YCbCr). if rawmode == "RGBA": # For "RGBA", data is stored as YCbCrA based on # negative RGB. The following trick works around # this problem : jpegmode, rawmode = "YCbCrK", "CMYK" else: jpegmode = None # let the decoder decide else: # The image is stored as defined by rawmode jpegmode = rawmode self.tile.append(("jpeg", (x, y, x+xtile, y+ytile), i32(s, i) + 28, (rawmode, jpegmode))) # FIXME: jpeg tables are tile dependent; the prefix # data must be placed in the tile descriptor itself! if jpeg_tables: self.tile_prefix = self.jpeg[jpeg_tables] else: raise IOError("unknown/invalid compression") x = x + xtile if x >= xsize: x, y = 0, y + ytile if y >= ysize: break # isn't really required self.stream = stream self.fp = None
[文档] def load(self): if not self.fp: self.fp = self.ole.openstream(self.stream[:2] + ["Subimage 0000 Data"]) ImageFile.ImageFile.load(self)
# # -------------------------------------------------------------------- Image.register_open(FpxImageFile.format, FpxImageFile, _accept) Image.register_extension(FpxImageFile.format, ".fpx")