PIL.PalmImagePlugin 源代码
#
# The Python Imaging Library.
# $Id$
#
##
# Image plugin for Palm pixmap images (output only).
##
from . import Image, ImageFile
from ._binary import o8
from ._binary import o16be as o16b
# fmt: off
_Palm8BitColormapValues = (
(255, 255, 255), (255, 204, 255), (255, 153, 255), (255, 102, 255),
(255, 51, 255), (255, 0, 255), (255, 255, 204), (255, 204, 204),
(255, 153, 204), (255, 102, 204), (255, 51, 204), (255, 0, 204),
(255, 255, 153), (255, 204, 153), (255, 153, 153), (255, 102, 153),
(255, 51, 153), (255, 0, 153), (204, 255, 255), (204, 204, 255),
(204, 153, 255), (204, 102, 255), (204, 51, 255), (204, 0, 255),
(204, 255, 204), (204, 204, 204), (204, 153, 204), (204, 102, 204),
(204, 51, 204), (204, 0, 204), (204, 255, 153), (204, 204, 153),
(204, 153, 153), (204, 102, 153), (204, 51, 153), (204, 0, 153),
(153, 255, 255), (153, 204, 255), (153, 153, 255), (153, 102, 255),
(153, 51, 255), (153, 0, 255), (153, 255, 204), (153, 204, 204),
(153, 153, 204), (153, 102, 204), (153, 51, 204), (153, 0, 204),
(153, 255, 153), (153, 204, 153), (153, 153, 153), (153, 102, 153),
(153, 51, 153), (153, 0, 153), (102, 255, 255), (102, 204, 255),
(102, 153, 255), (102, 102, 255), (102, 51, 255), (102, 0, 255),
(102, 255, 204), (102, 204, 204), (102, 153, 204), (102, 102, 204),
(102, 51, 204), (102, 0, 204), (102, 255, 153), (102, 204, 153),
(102, 153, 153), (102, 102, 153), (102, 51, 153), (102, 0, 153),
(51, 255, 255), (51, 204, 255), (51, 153, 255), (51, 102, 255),
(51, 51, 255), (51, 0, 255), (51, 255, 204), (51, 204, 204),
(51, 153, 204), (51, 102, 204), (51, 51, 204), (51, 0, 204),
(51, 255, 153), (51, 204, 153), (51, 153, 153), (51, 102, 153),
(51, 51, 153), (51, 0, 153), (0, 255, 255), (0, 204, 255),
(0, 153, 255), (0, 102, 255), (0, 51, 255), (0, 0, 255),
(0, 255, 204), (0, 204, 204), (0, 153, 204), (0, 102, 204),
(0, 51, 204), (0, 0, 204), (0, 255, 153), (0, 204, 153),
(0, 153, 153), (0, 102, 153), (0, 51, 153), (0, 0, 153),
(255, 255, 102), (255, 204, 102), (255, 153, 102), (255, 102, 102),
(255, 51, 102), (255, 0, 102), (255, 255, 51), (255, 204, 51),
(255, 153, 51), (255, 102, 51), (255, 51, 51), (255, 0, 51),
(255, 255, 0), (255, 204, 0), (255, 153, 0), (255, 102, 0),
(255, 51, 0), (255, 0, 0), (204, 255, 102), (204, 204, 102),
(204, 153, 102), (204, 102, 102), (204, 51, 102), (204, 0, 102),
(204, 255, 51), (204, 204, 51), (204, 153, 51), (204, 102, 51),
(204, 51, 51), (204, 0, 51), (204, 255, 0), (204, 204, 0),
(204, 153, 0), (204, 102, 0), (204, 51, 0), (204, 0, 0),
(153, 255, 102), (153, 204, 102), (153, 153, 102), (153, 102, 102),
(153, 51, 102), (153, 0, 102), (153, 255, 51), (153, 204, 51),
(153, 153, 51), (153, 102, 51), (153, 51, 51), (153, 0, 51),
(153, 255, 0), (153, 204, 0), (153, 153, 0), (153, 102, 0),
(153, 51, 0), (153, 0, 0), (102, 255, 102), (102, 204, 102),
(102, 153, 102), (102, 102, 102), (102, 51, 102), (102, 0, 102),
(102, 255, 51), (102, 204, 51), (102, 153, 51), (102, 102, 51),
(102, 51, 51), (102, 0, 51), (102, 255, 0), (102, 204, 0),
(102, 153, 0), (102, 102, 0), (102, 51, 0), (102, 0, 0),
(51, 255, 102), (51, 204, 102), (51, 153, 102), (51, 102, 102),
(51, 51, 102), (51, 0, 102), (51, 255, 51), (51, 204, 51),
(51, 153, 51), (51, 102, 51), (51, 51, 51), (51, 0, 51),
(51, 255, 0), (51, 204, 0), (51, 153, 0), (51, 102, 0),
(51, 51, 0), (51, 0, 0), (0, 255, 102), (0, 204, 102),
(0, 153, 102), (0, 102, 102), (0, 51, 102), (0, 0, 102),
(0, 255, 51), (0, 204, 51), (0, 153, 51), (0, 102, 51),
(0, 51, 51), (0, 0, 51), (0, 255, 0), (0, 204, 0),
(0, 153, 0), (0, 102, 0), (0, 51, 0), (17, 17, 17),
(34, 34, 34), (68, 68, 68), (85, 85, 85), (119, 119, 119),
(136, 136, 136), (170, 170, 170), (187, 187, 187), (221, 221, 221),
(238, 238, 238), (192, 192, 192), (128, 0, 0), (128, 0, 128),
(0, 128, 0), (0, 128, 128), (0, 0, 0), (0, 0, 0),
(0, 0, 0), (0, 0, 0), (0, 0, 0), (0, 0, 0),
(0, 0, 0), (0, 0, 0), (0, 0, 0), (0, 0, 0),
(0, 0, 0), (0, 0, 0), (0, 0, 0), (0, 0, 0),
(0, 0, 0), (0, 0, 0), (0, 0, 0), (0, 0, 0),
(0, 0, 0), (0, 0, 0), (0, 0, 0), (0, 0, 0),
(0, 0, 0), (0, 0, 0), (0, 0, 0), (0, 0, 0))
# fmt: on
# so build a prototype image to be used for palette resampling
[文档]def build_prototype_image():
image = Image.new("L", (1, len(_Palm8BitColormapValues)))
image.putdata(list(range(len(_Palm8BitColormapValues))))
palettedata = ()
for colormapValue in _Palm8BitColormapValues:
palettedata += colormapValue
palettedata += (0, 0, 0) * (256 - len(_Palm8BitColormapValues))
image.putpalette(palettedata)
return image
Palm8BitColormapImage = build_prototype_image()
# OK, we now have in Palm8BitColormapImage,
# a "P"-mode image with the right palette
#
# --------------------------------------------------------------------
_FLAGS = {"custom-colormap": 0x4000, "is-compressed": 0x8000, "has-transparent": 0x2000}
_COMPRESSION_TYPES = {"none": 0xFF, "rle": 0x01, "scanline": 0x00}
#
# --------------------------------------------------------------------
##
# (Internal) Image save plugin for the Palm format.
def _save(im, fp, filename):
if im.mode == "P":
# we assume this is a color Palm image with the standard colormap,
# unless the "info" dict has a "custom-colormap" field
rawmode = "P"
bpp = 8
version = 1
elif im.mode == "L":
if im.encoderinfo.get("bpp") in (1, 2, 4):
# this is 8-bit grayscale, so we shift it to get the high-order bits,
# and invert it because
# Palm does greyscale from white (0) to black (1)
bpp = im.encoderinfo["bpp"]
im = im.point(
lambda x, shift=8 - bpp, maxval=(1 << bpp) - 1: maxval - (x >> shift)
)
elif im.info.get("bpp") in (1, 2, 4):
# here we assume that even though the inherent mode is 8-bit grayscale,
# only the lower bpp bits are significant.
# We invert them to match the Palm.
bpp = im.info["bpp"]
im = im.point(lambda x, maxval=(1 << bpp) - 1: maxval - (x & maxval))
else:
raise OSError(f"cannot write mode {im.mode} as Palm")
# we ignore the palette here
im.mode = "P"
rawmode = "P;" + str(bpp)
version = 1
elif im.mode == "1":
# monochrome -- write it inverted, as is the Palm standard
rawmode = "1;I"
bpp = 1
version = 0
else:
raise OSError(f"cannot write mode {im.mode} as Palm")
#
# make sure image data is available
im.load()
# write header
cols = im.size[0]
rows = im.size[1]
rowbytes = int((cols + (16 // bpp - 1)) / (16 // bpp)) * 2
transparent_index = 0
compression_type = _COMPRESSION_TYPES["none"]
flags = 0
if im.mode == "P" and "custom-colormap" in im.info:
flags = flags & _FLAGS["custom-colormap"]
colormapsize = 4 * 256 + 2
colormapmode = im.palette.mode
colormap = im.getdata().getpalette()
else:
colormapsize = 0
if "offset" in im.info:
offset = (rowbytes * rows + 16 + 3 + colormapsize) // 4
else:
offset = 0
fp.write(o16b(cols) + o16b(rows) + o16b(rowbytes) + o16b(flags))
fp.write(o8(bpp))
fp.write(o8(version))
fp.write(o16b(offset))
fp.write(o8(transparent_index))
fp.write(o8(compression_type))
fp.write(o16b(0)) # reserved by Palm
# now write colormap if necessary
if colormapsize > 0:
fp.write(o16b(256))
for i in range(256):
fp.write(o8(i))
if colormapmode == "RGB":
fp.write(
o8(colormap[3 * i])
+ o8(colormap[3 * i + 1])
+ o8(colormap[3 * i + 2])
)
elif colormapmode == "RGBA":
fp.write(
o8(colormap[4 * i])
+ o8(colormap[4 * i + 1])
+ o8(colormap[4 * i + 2])
)
# now convert data to raw form
ImageFile._save(im, fp, [("raw", (0, 0) + im.size, 0, (rawmode, rowbytes, 1))])
if hasattr(fp, "flush"):
fp.flush()
#
# --------------------------------------------------------------------
Image.register_save("Palm", _save)
Image.register_extension("Palm", ".palm")
Image.register_mime("Palm", "image/palm")
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