PalmImagePlugin.py

#
# 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
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 grayscale 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:
            msg = f"cannot write mode {im.mode} as Palm"
            raise OSError(msg)

        # 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:
        msg = f"cannot write mode {im.mode} as Palm"
        raise OSError(msg)

    #
    # 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")