1 files changed, 161 insertions, 0 deletions
diff --git a/PIL/ImagePalette.py b/PIL/ImagePalette.py
new file mode 100644
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+++ b/PIL/ImagePalette.py
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+#
+# The Python Imaging Library.
+# $Id: ImagePalette.py 2339 2005-03-25 08:02:17Z fredrik $
+#
+# image palette object
+#
+# History:
+# 1996-03-11 fl   Rewritten.
+# 1997-01-03 fl   Up and running.
+# 1997-08-23 fl   Added load hack
+# 2001-04-16 fl   Fixed randint shadow bug in random()
+#
+# Copyright (c) 1997-2001 by Secret Labs AB
+# Copyright (c) 1996-1997 by Fredrik Lundh
+#
+# See the README file for information on usage and redistribution.
+#
+
+import array
+import Image
+
+##
+# Colour palette wrapper for palette mapped images.
+
+class ImagePalette:
+    "Colour palette for palette mapped images"
+
+    def __init__(self, mode = "RGB", palette = None):
+        self.mode = mode
+        self.rawmode = None # if set, palette contains raw data
+        self.palette = palette or range(256)*len(self.mode)
+        self.colors = {}
+        self.dirty = None
+        if len(self.mode)*256 != len(self.palette):
+            raise ValueError, "wrong palette size"
+
+    def getdata(self):
+        # experimental: get palette contains in format suitable
+        # for the low-level im.putpalette primitive
+        if self.rawmode:
+            return self.rawmode, self.palette
+        return self.mode + ";L", self.tostring()
+
+    def tostring(self):
+        # experimental: convert palette to string
+        if self.rawmode:
+            raise ValueError("palette contains raw palette data")
+        if Image.isStringType(self.palette):
+            return self.palette
+        return array.array("B", self.palette).tostring()
+
+    def getcolor(self, color):
+        # experimental: given an rgb tuple, allocate palette entry
+        if self.rawmode:
+            raise ValueError("palette contains raw palette data")
+        if Image.isTupleType(color):
+            try:
+                return self.colors[color]
+            except KeyError:
+                # allocate new color slot
+                if Image.isStringType(self.palette):
+                    self.palette = map(int, self.palette)
+                index = len(self.colors)
+                if index >= 256:
+                    raise ValueError("cannot allocate more than 256 colors")
+                self.colors[color] = index
+                self.palette[index] = color[0]
+                self.palette[index+256] = color[1]
+                self.palette[index+512] = color[2]
+                self.dirty = 1
+                return index
+        else:
+            raise ValueError("unknown color specifier: %r" % color)
+
+    def save(self, fp):
+        # (experimental) save palette to text file
+        if self.rawmode:
+            raise ValueError("palette contains raw palette data")
+        if type(fp) == type(""):
+            fp = open(fp, "w")
+        fp.write("# Palette\n")
+        fp.write("# Mode: %s\n" % self.mode)
+        for i in range(256):
+            fp.write("%d" % i)
+            for j in range(i, len(self.palette), 256):
+                fp.write(" %d" % self.palette[j])
+            fp.write("\n")
+        fp.close()
+
+# --------------------------------------------------------------------
+# Internal
+
+def raw(rawmode, data):
+    palette = ImagePalette()
+    palette.rawmode = rawmode
+    palette.palette = data
+    palette.dirty = 1
+    return palette
+
+# --------------------------------------------------------------------
+# Factories
+
+def new(mode, data):
+    return Image.core.new_palette(mode, data)
+
+def negative(mode = "RGB"):
+    palette = range(256)
+    palette.reverse()
+    return ImagePalette(mode, palette * len(mode))
+
+def random(mode = "RGB"):
+    from random import randint
+    palette = map(lambda a, randint=randint:
+                  randint(0, 255), [0]*256*len(mode))
+    return ImagePalette(mode, palette)
+
+def wedge(mode = "RGB"):
+    return ImagePalette(mode, range(256) * len(mode))
+
+def load(filename):
+
+    # FIXME: supports GIMP gradients only
+
+    fp = open(filename, "rb")
+
+    lut = None
+
+    if not lut:
+        try:
+            import GimpPaletteFile
+            fp.seek(0)
+            p = GimpPaletteFile.GimpPaletteFile(fp)
+            lut = p.getpalette()
+        except (SyntaxError, ValueError):
+            pass
+
+    if not lut:
+        try:
+            import GimpGradientFile
+            fp.seek(0)
+            p = GimpGradientFile.GimpGradientFile(fp)
+            lut = p.getpalette()
+        except (SyntaxError, ValueError):
+            pass
+
+    if not lut:
+        try:
+            import PaletteFile
+            fp.seek(0)
+            p = PaletteFile.PaletteFile(fp)
+            lut = p.getpalette()
+        except (SyntaxError, ValueError):
+            pass
+
+    if not lut:
+        raise IOError, "cannot load palette"
+
+    return lut # data, rawmode
+
+
+# add some psuedocolour palettes as well