Pillow/PIL/PalmImagePlugin.py

#
# The Python Imaging Library.
# $Id$
#

##
# Image plugin for Palm pixmap images (output only).
##

__version__ = "1.0"

from PIL import Image, ImageFile, _binary

_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))


# so build a prototype image to be used for palette resampling
def build_prototype_image():
    image = Image.new("L", (1, len(_Palm8BitColormapValues),))
    image.putdata(list(range(len(_Palm8BitColormapValues))))
    palettedata = ()
    for i in range(len(_Palm8BitColormapValues)):
        palettedata = palettedata + _Palm8BitColormapValues[i]
    for i in range(256 - len(_Palm8BitColormapValues)):
        palettedata = palettedata + (0, 0, 0)
    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,
    }

o8 = _binary.o8
o16b = _binary.o16be


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

##
# (Internal) Image save plugin for the Palm format.

def _save(im, fp, filename, check=0):

    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" and
          "bpp" in im.encoderinfo and
          im.encoderinfo["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))
        # we ignore the palette here
        im.mode = "P"
        rawmode = "P;" + str(bpp)
        version = 1

    elif im.mode == "L" and "bpp" in im.info and im.info["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))
        # 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 IOError("cannot write mode %s as Palm" % im.mode)

    if check:
        return check

    #
    # 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))])

    fp.flush()


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

Image.register_save("Palm", _save)

Image.register_extension("Palm", ".palm")

Image.register_mime("Palm", "image/palm")