diff --git a/PIL/Image.py b/PIL/Image.py
index 27acc8500..b79335a13 100644
--- a/PIL/Image.py
+++ b/PIL/Image.py
@@ -143,11 +143,23 @@ FLOYDSTEINBERG = 3 # default
 WEB = 0
 ADAPTIVE = 1
 
+MEDIANCUT = 0
+MAXCOVERAGE = 1
+FASTOCTREE = 2
+
 # categories
 NORMAL = 0
 SEQUENCE = 1
 CONTAINER = 2
 
+if hasattr(core, 'DEFAULT_STRATEGY'):
+    DEFAULT_STRATEGY = core.DEFAULT_STRATEGY
+    FILTERED = core.FILTERED
+    HUFFMAN_ONLY = core.HUFFMAN_ONLY
+    RLE = core.RLE
+    FIXED = core.FIXED
+
+
 # --------------------------------------------------------------------
 # Registries
 
@@ -616,8 +628,12 @@ class Image:
             self.palette.mode = "RGB"
             self.palette.rawmode = None
             if "transparency" in self.info:
-                self.im.putpalettealpha(self.info["transparency"], 0)
+                if isinstance(self.info["transparency"], str):
+                    self.im.putpalettealphas(self.info["transparency"])
+                else:
+                    self.im.putpalettealpha(self.info["transparency"], 0)
                 self.palette.mode = "RGBA"
+
         if self.im:
             return self.im.pixel_access(self.readonly)
 
@@ -714,6 +730,7 @@ class Image:
         # methods:
         #    0 = median cut
         #    1 = maximum coverage
+        #    2 = fast octree
 
         # NOTE: this functionality will be moved to the extended
         # quantizer interface in a later version of PIL.
diff --git a/PIL/PngImagePlugin.py b/PIL/PngImagePlugin.py
index 0eee64942..96e4431fc 100644
--- a/PIL/PngImagePlugin.py
+++ b/PIL/PngImagePlugin.py
@@ -70,6 +70,8 @@ _MODES = {
 }
 
 
+_simple_palette = re.compile(b'^\xff+\x00+$')
+
 # --------------------------------------------------------------------
 # Support classes.  Suitable for PNG and related formats like MNG etc.
 
@@ -251,9 +253,12 @@ class PngStream(ChunkStream):
         # transparency
         s = ImageFile._safe_read(self.fp, len)
         if self.im_mode == "P":
-            i = s.find(b"\0")
-            if i >= 0:
-                self.im_info["transparency"] = i
+            if _simple_palette.match(s):
+                i = s.find(b"\0")
+                if i >= 0:
+                    self.im_info["transparency"] = i
+            else:
+                self.im_info["transparency"] = s
         elif self.im_mode == "L":
             self.im_info["transparency"] = i16(s)
         elif self.im_mode == "RGB":
@@ -513,7 +518,10 @@ def _save(im, fp, filename, chunk=putchunk, check=0):
     else:
         dictionary = b""
 
-    im.encoderconfig = ("optimize" in im.encoderinfo, dictionary)
+    im.encoderconfig = ("optimize" in im.encoderinfo,
+        im.encoderinfo.get("compress_level", -1),
+        im.encoderinfo.get("compress_type", -1),
+        dictionary)
 
     # get the corresponding PNG mode
     try:
@@ -551,6 +559,10 @@ def _save(im, fp, filename, chunk=putchunk, check=0):
             chunk(fp, b"tRNS", o16(red) + o16(green) + o16(blue))
         else:
             raise IOError("cannot use transparency for this mode")
+    else:
+        if im.mode == "P" and im.im.getpalettemode() == "RGBA":
+            alpha = im.im.getpalette("RGBA", "A")
+            chunk(fp, "tRNS", alpha)
 
     if 0:
         # FIXME: to be supported some day
diff --git a/Tests/test_file_png.py b/Tests/test_file_png.py
index 7086d8709..c8ee36c93 100644
--- a/Tests/test_file_png.py
+++ b/Tests/test_file_png.py
@@ -117,6 +117,17 @@ def test_interlace():
 
     assert_no_exception(lambda: im.load())
 
+def test_load_transparent_p():
+    file = "Tests/images/pil123p.png"
+    im = Image.open(file)
+
+    assert_image(im, "P", (162, 150))
+    im = im.convert("RGBA")
+    assert_image(im, "RGBA", (162, 150))
+
+    # image has 124 uniqe qlpha values
+    assert_equal(len(im.split()[3].getcolors()), 124)
+
 def test_load_verify():
     # Check open/load/verify exception (@PIL150)
 
diff --git a/Tests/test_image_quantize.py b/Tests/test_image_quantize.py
index 5dcbab7fe..ce22bd5a6 100644
--- a/Tests/test_image_quantize.py
+++ b/Tests/test_image_quantize.py
@@ -13,3 +13,10 @@ def test_sanity():
     im = im.quantize(palette=lena("P"))
     assert_image(im, "P", im.size)
     
+def test_octree_quantize():
+    im = lena()
+
+    im = im.quantize(100, Image.FASTOCTREE)
+    assert_image(im, "P", im.size)
+
+    assert len(im.getcolors()) == 100
\ No newline at end of file
diff --git a/_imaging.c b/_imaging.c
index 6bf3fe598..0ced4d488 100644
--- a/_imaging.c
+++ b/_imaging.c
@@ -65,7 +65,7 @@
  * 2005-10-02 fl   Added access proxy
  * 2006-06-18 fl   Always draw last point in polyline
  *
- * Copyright (c) 1997-2006 by Secret Labs AB 
+ * Copyright (c) 1997-2006 by Secret Labs AB
  * Copyright (c) 1995-2006 by Fredrik Lundh
  *
  * See the README file for information on usage and redistribution.
@@ -157,7 +157,7 @@ typedef struct {
 
 static PyTypeObject PixelAccess_Type;
 
-PyObject* 
+PyObject*
 PyImagingNew(Imaging imOut)
 {
     ImagingObject* imagep;
@@ -584,7 +584,7 @@ getink(PyObject* color, Imaging im, char* ink)
 /* FACTORIES								*/
 /* -------------------------------------------------------------------- */
 
-static PyObject* 
+static PyObject*
 _fill(PyObject* self, PyObject* args)
 {
     char* mode;
@@ -592,7 +592,7 @@ _fill(PyObject* self, PyObject* args)
     PyObject* color;
     char buffer[4];
     Imaging im;
-    
+
     xsize = ysize = 256;
     color = NULL;
 
@@ -616,7 +616,7 @@ _fill(PyObject* self, PyObject* args)
     return PyImagingNew(im);
 }
 
-static PyObject* 
+static PyObject*
 _new(PyObject* self, PyObject* args)
 {
     char* mode;
@@ -628,7 +628,7 @@ _new(PyObject* self, PyObject* args)
     return PyImagingNew(ImagingNew(mode, xsize, ysize));
 }
 
-static PyObject* 
+static PyObject*
 _new_array(PyObject* self, PyObject* args)
 {
     char* mode;
@@ -640,7 +640,7 @@ _new_array(PyObject* self, PyObject* args)
     return PyImagingNew(ImagingNewArray(mode, xsize, ysize));
 }
 
-static PyObject* 
+static PyObject*
 _new_block(PyObject* self, PyObject* args)
 {
     char* mode;
@@ -652,7 +652,7 @@ _new_block(PyObject* self, PyObject* args)
     return PyImagingNew(ImagingNewBlock(mode, xsize, ysize));
 }
 
-static PyObject* 
+static PyObject*
 _getcount(PyObject* self, PyObject* args)
 {
     if (!PyArg_ParseTuple(args, ":getcount"))
@@ -661,7 +661,7 @@ _getcount(PyObject* self, PyObject* args)
     return PyInt_FromLong(ImagingNewCount);
 }
 
-static PyObject* 
+static PyObject*
 _linear_gradient(PyObject* self, PyObject* args)
 {
     char* mode;
@@ -672,7 +672,7 @@ _linear_gradient(PyObject* self, PyObject* args)
     return PyImagingNew(ImagingFillLinearGradient(mode));
 }
 
-static PyObject* 
+static PyObject*
 _radial_gradient(PyObject* self, PyObject* args)
 {
     char* mode;
@@ -683,7 +683,7 @@ _radial_gradient(PyObject* self, PyObject* args)
     return PyImagingNew(ImagingFillRadialGradient(mode));
 }
 
-static PyObject* 
+static PyObject*
 _open_ppm(PyObject* self, PyObject* args)
 {
     char* filename;
@@ -708,13 +708,13 @@ _alpha_composite(ImagingObject* self, PyObject* args)
     return PyImagingNew(ImagingAlphaComposite(imagep1->image, imagep2->image));
 }
 
-static PyObject* 
+static PyObject*
 _blend(ImagingObject* self, PyObject* args)
 {
     ImagingObject* imagep1;
     ImagingObject* imagep2;
     double alpha;
-    
+
     alpha = 0.5;
     if (!PyArg_ParseTuple(args, "O!O!|d",
 			  &Imaging_Type, &imagep1,
@@ -730,7 +730,7 @@ _blend(ImagingObject* self, PyObject* args)
 /* METHODS								*/
 /* -------------------------------------------------------------------- */
 
-static PyObject* 
+static PyObject*
 _convert(ImagingObject* self, PyObject* args)
 {
     char* mode;
@@ -754,7 +754,7 @@ _convert(ImagingObject* self, PyObject* args)
     return PyImagingNew(ImagingConvert(self->image, mode, paletteimage ? paletteimage->image->palette : NULL, dither));
 }
 
-static PyObject* 
+static PyObject*
 _convert2(ImagingObject* self, PyObject* args)
 {
     ImagingObject* imagep1;
@@ -771,7 +771,7 @@ _convert2(ImagingObject* self, PyObject* args)
     return Py_None;
 }
 
-static PyObject* 
+static PyObject*
 _convert_matrix(ImagingObject* self, PyObject* args)
 {
     char* mode;
@@ -788,7 +788,7 @@ _convert_matrix(ImagingObject* self, PyObject* args)
     return PyImagingNew(ImagingConvertMatrix(self->image, mode, m));
 }
 
-static PyObject* 
+static PyObject*
 _copy(ImagingObject* self, PyObject* args)
 {
     if (!PyArg_ParseTuple(args, ""))
@@ -797,7 +797,7 @@ _copy(ImagingObject* self, PyObject* args)
     return PyImagingNew(ImagingCopy(self->image));
 }
 
-static PyObject* 
+static PyObject*
 _copy2(ImagingObject* self, PyObject* args)
 {
     ImagingObject* imagep1;
@@ -814,7 +814,7 @@ _copy2(ImagingObject* self, PyObject* args)
     return Py_None;
 }
 
-static PyObject* 
+static PyObject*
 _crop(ImagingObject* self, PyObject* args)
 {
     int x0, y0, x1, y1;
@@ -824,7 +824,7 @@ _crop(ImagingObject* self, PyObject* args)
     return PyImagingNew(ImagingCrop(self->image, x0, y0, x1, y1));
 }
 
-static PyObject* 
+static PyObject*
 _expand(ImagingObject* self, PyObject* args)
 {
     int x, y;
@@ -835,7 +835,7 @@ _expand(ImagingObject* self, PyObject* args)
     return PyImagingNew(ImagingExpand(self->image, x, y, mode));
 }
 
-static PyObject* 
+static PyObject*
 _filter(ImagingObject* self, PyObject* args)
 {
     PyObject* imOut;
@@ -848,7 +848,7 @@ _filter(ImagingObject* self, PyObject* args)
     if (!PyArg_ParseTuple(args, "(ii)ffO", &xsize, &ysize,
                          &divisor, &offset, &kernel))
         return NULL;
-    
+
     /* get user-defined kernel */
     kerneldata = getlist(kernel, &kernelsize, NULL, TYPE_FLOAT32);
     if (!kerneldata)
@@ -868,7 +868,7 @@ _filter(ImagingObject* self, PyObject* args)
 }
 
 #ifdef WITH_UNSHARPMASK
-static PyObject* 
+static PyObject*
 _gaussian_blur(ImagingObject* self, PyObject* args)
 {
     Imaging imIn;
@@ -890,7 +890,7 @@ _gaussian_blur(ImagingObject* self, PyObject* args)
 }
 #endif
 
-static PyObject* 
+static PyObject*
 _getpalette(ImagingObject* self, PyObject* args)
 {
     PyObject* palette;
@@ -924,6 +924,17 @@ _getpalette(ImagingObject* self, PyObject* args)
     return palette;
 }
 
+static PyObject*
+_getpalettemode(ImagingObject* self, PyObject* args)
+{
+    if (!self->image->palette) {
+	PyErr_SetString(PyExc_ValueError, no_palette);
+	return NULL;
+    }
+
+    return PyString_FromString(self->image->palette->mode);
+}
+
 static inline int
 _getxy(PyObject* xy, int* x, int *y)
 {
@@ -931,7 +942,7 @@ _getxy(PyObject* xy, int* x, int *y)
 
     if (!PyTuple_Check(xy) || PyTuple_GET_SIZE(xy) != 2)
         goto badarg;
-        
+
     value = PyTuple_GET_ITEM(xy, 0);
     if (PyInt_Check(value))
         *x = PyInt_AS_LONG(value);
@@ -965,7 +976,7 @@ _getxy(PyObject* xy, int* x, int *y)
     return -1;
 }
 
-static PyObject* 
+static PyObject*
 _getpixel(ImagingObject* self, PyObject* args)
 {
     PyObject* xy;
@@ -1065,7 +1076,7 @@ _histogram(ImagingObject* self, PyObject* args)
 }
 
 #ifdef WITH_MODEFILTER
-static PyObject* 
+static PyObject*
 _modefilter(ImagingObject* self, PyObject* args)
 {
     int size;
@@ -1076,7 +1087,7 @@ _modefilter(ImagingObject* self, PyObject* args)
 }
 #endif
 
-static PyObject* 
+static PyObject*
 _offset(ImagingObject* self, PyObject* args)
 {
     int xoffset, yoffset;
@@ -1086,7 +1097,7 @@ _offset(ImagingObject* self, PyObject* args)
     return PyImagingNew(ImagingOffset(self->image, xoffset, yoffset));
 }
 
-static PyObject* 
+static PyObject*
 _paste(ImagingObject* self, PyObject* args)
 {
     int status;
@@ -1251,7 +1262,7 @@ _putdata(ImagingObject* self, PyObject* args)
                         x = image->xsize;
                     memcpy(image->image8[y], p+i, x);
                 }
-            else 
+            else
                 /* Scaled and clipped string data */
                 for (i = x = y = 0; i < n; i++) {
                     image->image8[y][x] = CLIP((int) (p[i] * scale + offset));
@@ -1355,7 +1366,7 @@ _putdata(ImagingObject* self, PyObject* args)
 #ifdef WITH_QUANTIZE
 
 #include "Quant.h"
-static PyObject* 
+static PyObject*
 _quantize(ImagingObject* self, PyObject* args)
 {
     int colours = 256;
@@ -1375,7 +1386,7 @@ _quantize(ImagingObject* self, PyObject* args)
 }
 #endif
 
-static PyObject* 
+static PyObject*
 _putpalette(ImagingObject* self, PyObject* args)
 {
     ImagingShuffler unpack;
@@ -1410,7 +1421,7 @@ _putpalette(ImagingObject* self, PyObject* args)
     return Py_None;
 }
 
-static PyObject* 
+static PyObject*
 _putpalettealpha(ImagingObject* self, PyObject* args)
 {
     int index;
@@ -1435,7 +1446,35 @@ _putpalettealpha(ImagingObject* self, PyObject* args)
     return Py_None;
 }
 
-static PyObject* 
+static PyObject*
+_putpalettealphas(ImagingObject* self, PyObject* args)
+{
+    int i;
+    UINT8 *values;
+    int length;
+    if (!PyArg_ParseTuple(args, "s#", &values, &length))
+	return NULL;
+
+    if (!self->image->palette) {
+	PyErr_SetString(PyExc_ValueError, no_palette);
+	return NULL;
+    }
+
+    if (length  > 256) {
+	PyErr_SetString(PyExc_ValueError, outside_palette);
+	return NULL;
+    }
+
+    strcpy(self->image->palette->mode, "RGBA");
+    for (i=0; i<length; i++) {
+	self->image->palette->palette[i*4+3] = (UINT8) values[i];
+    }
+
+    Py_INCREF(Py_None);
+    return Py_None;
+}
+
+static PyObject*
 _putpixel(ImagingObject* self, PyObject* args)
 {
     Imaging im;
@@ -1447,7 +1486,7 @@ _putpixel(ImagingObject* self, PyObject* args)
 	return NULL;
 
     im = self->image;
-    
+
     if (x < 0 || x >= im->xsize || y < 0 || y >= im->ysize) {
 	PyErr_SetString(PyExc_IndexError, outside_image);
 	return NULL;
@@ -1464,7 +1503,7 @@ _putpixel(ImagingObject* self, PyObject* args)
 }
 
 #ifdef WITH_RANKFILTER
-static PyObject* 
+static PyObject*
 _rankfilter(ImagingObject* self, PyObject* args)
 {
     int size, rank;
@@ -1475,7 +1514,7 @@ _rankfilter(ImagingObject* self, PyObject* args)
 }
 #endif
 
-static PyObject* 
+static PyObject*
 _resize(ImagingObject* self, PyObject* args)
 {
     Imaging imIn;
@@ -1491,16 +1530,16 @@ _resize(ImagingObject* self, PyObject* args)
     imOut = ImagingNew(imIn->mode, xsize, ysize);
     if (imOut)
 	(void) ImagingResize(imOut, imIn, filter);
-    
+
     return PyImagingNew(imOut);
 }
 
-static PyObject* 
+static PyObject*
 _rotate(ImagingObject* self, PyObject* args)
 {
     Imaging imOut;
     Imaging imIn;
-    
+
     double theta;
     int filter = IMAGING_TRANSFORM_NEAREST;
     if (!PyArg_ParseTuple(args, "d|i", &theta, &filter))
@@ -1546,7 +1585,7 @@ _rotate(ImagingObject* self, PyObject* args)
 #define IS_RGB(mode)\
     (!strcmp(mode, "RGB") || !strcmp(mode, "RGBA") || !strcmp(mode, "RGBX"))
 
-static PyObject* 
+static PyObject*
 im_setmode(ImagingObject* self, PyObject* args)
 {
     /* attempt to modify the mode of an image in place */
@@ -1584,7 +1623,7 @@ im_setmode(ImagingObject* self, PyObject* args)
     return Py_None;
 }
 
-static PyObject* 
+static PyObject*
 _stretch(ImagingObject* self, PyObject* args)
 {
     Imaging imIn;
@@ -1601,7 +1640,7 @@ _stretch(ImagingObject* self, PyObject* args)
     /* two-pass resize: minimize size of intermediate image */
     if (imIn->xsize * ysize < xsize * imIn->ysize)
         imTemp = ImagingNew(imIn->mode, imIn->xsize, ysize);
-    else 
+    else
         imTemp = ImagingNew(imIn->mode, xsize, imIn->ysize);
     if (!imTemp)
         return NULL;
@@ -1626,11 +1665,11 @@ _stretch(ImagingObject* self, PyObject* args)
     }
 
     ImagingDelete(imTemp);
-    
+
     return PyImagingNew(imOut);
 }
 
-static PyObject* 
+static PyObject*
 _transform2(ImagingObject* self, PyObject* args)
 {
     static const char* wrong_number = "wrong number of matrix entries";
@@ -1705,7 +1744,7 @@ _transform2(ImagingObject* self, PyObject* args)
     return Py_None;
 }
 
-static PyObject* 
+static PyObject*
 _transpose(ImagingObject* self, PyObject* args)
 {
     Imaging imIn;
@@ -1716,7 +1755,7 @@ _transpose(ImagingObject* self, PyObject* args)
 	return NULL;
 
     imIn = self->image;
-    
+
     switch (op) {
     case 0: /* flip left right */
     case 1: /* flip top bottom */
@@ -1755,7 +1794,7 @@ _transpose(ImagingObject* self, PyObject* args)
 }
 
 #ifdef WITH_UNSHARPMASK
-static PyObject* 
+static PyObject*
 _unsharp_mask(ImagingObject* self, PyObject* args)
 {
     Imaging imIn;
@@ -1781,13 +1820,13 @@ _unsharp_mask(ImagingObject* self, PyObject* args)
 
 /* -------------------------------------------------------------------- */
 
-static PyObject* 
+static PyObject*
 _isblock(ImagingObject* self, PyObject* args)
 {
     return PyInt_FromLong((long) self->image->block);
 }
 
-static PyObject* 
+static PyObject*
 _getbbox(ImagingObject* self, PyObject* args)
 {
     int bbox[4];
@@ -1799,7 +1838,7 @@ _getbbox(ImagingObject* self, PyObject* args)
     return Py_BuildValue("iiii", bbox[0], bbox[1], bbox[2], bbox[3]);
 }
 
-static PyObject* 
+static PyObject*
 _getcolors(ImagingObject* self, PyObject* args)
 {
     ImagingColorItem* items;
@@ -1833,7 +1872,7 @@ _getcolors(ImagingObject* self, PyObject* args)
     return out;
 }
 
-static PyObject* 
+static PyObject*
 _getextrema(ImagingObject* self, PyObject* args)
 {
     union {
@@ -1842,7 +1881,7 @@ _getextrema(ImagingObject* self, PyObject* args)
         FLOAT32 f[2];
     } extrema;
     int status;
-    
+
     status = ImagingGetExtrema(self->image, &extrema);
     if (status < 0)
         return NULL;
@@ -1861,7 +1900,7 @@ _getextrema(ImagingObject* self, PyObject* args)
     return Py_None;
 }
 
-static PyObject* 
+static PyObject*
 _getprojection(ImagingObject* self, PyObject* args)
 {
     unsigned char* xprofile;
@@ -1891,7 +1930,7 @@ _getprojection(ImagingObject* self, PyObject* args)
 
 /* -------------------------------------------------------------------- */
 
-static PyObject* 
+static PyObject*
 _getband(ImagingObject* self, PyObject* args)
 {
     int band;
@@ -1902,7 +1941,7 @@ _getband(ImagingObject* self, PyObject* args)
     return PyImagingNew(ImagingGetBand(self->image, band));
 }
 
-static PyObject* 
+static PyObject*
 _fillband(ImagingObject* self, PyObject* args)
 {
     int band;
@@ -1913,12 +1952,12 @@ _fillband(ImagingObject* self, PyObject* args)
 
     if (!ImagingFillBand(self->image, band, color))
         return NULL;
-    
+
     Py_INCREF(Py_None);
     return Py_None;
 }
 
-static PyObject* 
+static PyObject*
 _putband(ImagingObject* self, PyObject* args)
 {
     ImagingObject* imagep;
@@ -1939,13 +1978,13 @@ _putband(ImagingObject* self, PyObject* args)
 
 #ifdef WITH_IMAGECHOPS
 
-static PyObject* 
+static PyObject*
 _chop_invert(ImagingObject* self, PyObject* args)
 {
     return PyImagingNew(ImagingNegative(self->image));
 }
 
-static PyObject* 
+static PyObject*
 _chop_lighter(ImagingObject* self, PyObject* args)
 {
     ImagingObject* imagep;
@@ -1956,7 +1995,7 @@ _chop_lighter(ImagingObject* self, PyObject* args)
     return PyImagingNew(ImagingChopLighter(self->image, imagep->image));
 }
 
-static PyObject* 
+static PyObject*
 _chop_darker(ImagingObject* self, PyObject* args)
 {
     ImagingObject* imagep;
@@ -1967,7 +2006,7 @@ _chop_darker(ImagingObject* self, PyObject* args)
     return PyImagingNew(ImagingChopDarker(self->image, imagep->image));
 }
 
-static PyObject* 
+static PyObject*
 _chop_difference(ImagingObject* self, PyObject* args)
 {
     ImagingObject* imagep;
@@ -1978,7 +2017,7 @@ _chop_difference(ImagingObject* self, PyObject* args)
     return PyImagingNew(ImagingChopDifference(self->image, imagep->image));
 }
 
-static PyObject* 
+static PyObject*
 _chop_multiply(ImagingObject* self, PyObject* args)
 {
     ImagingObject* imagep;
@@ -1989,7 +2028,7 @@ _chop_multiply(ImagingObject* self, PyObject* args)
     return PyImagingNew(ImagingChopMultiply(self->image, imagep->image));
 }
 
-static PyObject* 
+static PyObject*
 _chop_screen(ImagingObject* self, PyObject* args)
 {
     ImagingObject* imagep;
@@ -2000,7 +2039,7 @@ _chop_screen(ImagingObject* self, PyObject* args)
     return PyImagingNew(ImagingChopScreen(self->image, imagep->image));
 }
 
-static PyObject* 
+static PyObject*
 _chop_add(ImagingObject* self, PyObject* args)
 {
     ImagingObject* imagep;
@@ -2018,7 +2057,7 @@ _chop_add(ImagingObject* self, PyObject* args)
 				       scale, offset));
 }
 
-static PyObject* 
+static PyObject*
 _chop_subtract(ImagingObject* self, PyObject* args)
 {
     ImagingObject* imagep;
@@ -2036,7 +2075,7 @@ _chop_subtract(ImagingObject* self, PyObject* args)
 					    scale, offset));
 }
 
-static PyObject* 
+static PyObject*
 _chop_and(ImagingObject* self, PyObject* args)
 {
     ImagingObject* imagep;
@@ -2047,7 +2086,7 @@ _chop_and(ImagingObject* self, PyObject* args)
     return PyImagingNew(ImagingChopAnd(self->image, imagep->image));
 }
 
-static PyObject* 
+static PyObject*
 _chop_or(ImagingObject* self, PyObject* args)
 {
     ImagingObject* imagep;
@@ -2058,7 +2097,7 @@ _chop_or(ImagingObject* self, PyObject* args)
     return PyImagingNew(ImagingChopOr(self->image, imagep->image));
 }
 
-static PyObject* 
+static PyObject*
 _chop_xor(ImagingObject* self, PyObject* args)
 {
     ImagingObject* imagep;
@@ -2069,7 +2108,7 @@ _chop_xor(ImagingObject* self, PyObject* args)
     return PyImagingNew(ImagingChopXor(self->image, imagep->image));
 }
 
-static PyObject* 
+static PyObject*
 _chop_add_modulo(ImagingObject* self, PyObject* args)
 {
     ImagingObject* imagep;
@@ -2080,7 +2119,7 @@ _chop_add_modulo(ImagingObject* self, PyObject* args)
     return PyImagingNew(ImagingChopAddModulo(self->image, imagep->image));
 }
 
-static PyObject* 
+static PyObject*
 _chop_subtract_modulo(ImagingObject* self, PyObject* args)
 {
     ImagingObject* imagep;
@@ -2274,7 +2313,7 @@ _draw_dealloc(ImagingDrawObject* self)
 
 extern int PyPath_Flatten(PyObject* data, double **xy);
 
-static PyObject* 
+static PyObject*
 _draw_ink(ImagingDrawObject* self, PyObject* args)
 {
     INT32 ink = 0;
@@ -2289,7 +2328,7 @@ _draw_ink(ImagingDrawObject* self, PyObject* args)
     return PyInt_FromLong((int) ink);
 }
 
-static PyObject* 
+static PyObject*
 _draw_arc(ImagingDrawObject* self, PyObject* args)
 {
     int x0, y0, x1, y1;
@@ -2309,7 +2348,7 @@ _draw_arc(ImagingDrawObject* self, PyObject* args)
     return Py_None;
 }
 
-static PyObject* 
+static PyObject*
 _draw_bitmap(ImagingDrawObject* self, PyObject* args)
 {
     double *xy;
@@ -2346,7 +2385,7 @@ _draw_bitmap(ImagingDrawObject* self, PyObject* args)
     return Py_None;
 }
 
-static PyObject* 
+static PyObject*
 _draw_chord(ImagingDrawObject* self, PyObject* args)
 {
     int x0, y0, x1, y1;
@@ -2364,7 +2403,7 @@ _draw_chord(ImagingDrawObject* self, PyObject* args)
     return Py_None;
 }
 
-static PyObject* 
+static PyObject*
 _draw_ellipse(ImagingDrawObject* self, PyObject* args)
 {
     double* xy;
@@ -2391,7 +2430,7 @@ _draw_ellipse(ImagingDrawObject* self, PyObject* args)
         self->image->image, (int) xy[0], (int) xy[1], (int) xy[2], (int) xy[3],
         &ink, fill, self->blend
         );
-    
+
     free(xy);
 
     if (n < 0)
@@ -2401,7 +2440,7 @@ _draw_ellipse(ImagingDrawObject* self, PyObject* args)
     return Py_None;
 }
 
-static PyObject* 
+static PyObject*
 _draw_line(ImagingDrawObject* self, PyObject* args)
 {
     int x0, y0, x1, y1;
@@ -2417,7 +2456,7 @@ _draw_line(ImagingDrawObject* self, PyObject* args)
     return Py_None;
 }
 
-static PyObject* 
+static PyObject*
 _draw_lines(ImagingDrawObject* self, PyObject* args)
 {
     double *xy;
@@ -2470,7 +2509,7 @@ _draw_lines(ImagingDrawObject* self, PyObject* args)
     return Py_None;
 }
 
-static PyObject* 
+static PyObject*
 _draw_point(ImagingDrawObject* self, PyObject* args)
 {
     int x, y;
@@ -2485,7 +2524,7 @@ _draw_point(ImagingDrawObject* self, PyObject* args)
     return Py_None;
 }
 
-static PyObject* 
+static PyObject*
 _draw_points(ImagingDrawObject* self, PyObject* args)
 {
     double *xy;
@@ -2520,7 +2559,7 @@ _draw_points(ImagingDrawObject* self, PyObject* args)
 /* from outline.c */
 extern ImagingOutline PyOutline_AsOutline(PyObject* outline);
 
-static PyObject* 
+static PyObject*
 _draw_outline(ImagingDrawObject* self, PyObject* args)
 {
     ImagingOutline outline;
@@ -2547,7 +2586,7 @@ _draw_outline(ImagingDrawObject* self, PyObject* args)
 
 #endif
 
-static PyObject* 
+static PyObject*
 _draw_pieslice(ImagingDrawObject* self, PyObject* args)
 {
     int x0, y0, x1, y1;
@@ -2565,7 +2604,7 @@ _draw_pieslice(ImagingDrawObject* self, PyObject* args)
     return Py_None;
 }
 
-static PyObject* 
+static PyObject*
 _draw_polygon(ImagingDrawObject* self, PyObject* args)
 {
     double *xy;
@@ -2611,7 +2650,7 @@ _draw_polygon(ImagingDrawObject* self, PyObject* args)
     return Py_None;
 }
 
-static PyObject* 
+static PyObject*
 _draw_rectangle(ImagingDrawObject* self, PyObject* args)
 {
     double* xy;
@@ -2638,7 +2677,7 @@ _draw_rectangle(ImagingDrawObject* self, PyObject* args)
         self->image->image, (int) xy[0], (int) xy[1],
         (int) xy[2], (int) xy[3], &ink, fill, self->blend
         );
-    
+
     free(xy);
 
     if (n < 0)
@@ -2749,7 +2788,7 @@ pixel_access_setitem(PixelAccessObject *self, PyObject *xy, PyObject *color)
 
 #ifdef WITH_EFFECTS
 
-static PyObject* 
+static PyObject*
 _effect_mandelbrot(ImagingObject* self, PyObject* args)
 {
     int xsize = 512;
@@ -2768,7 +2807,7 @@ _effect_mandelbrot(ImagingObject* self, PyObject* args)
     return PyImagingNew(ImagingEffectMandelbrot(xsize, ysize, extent, quality));
 }
 
-static PyObject* 
+static PyObject*
 _effect_noise(ImagingObject* self, PyObject* args)
 {
     int xsize, ysize;
@@ -2779,7 +2818,7 @@ _effect_noise(ImagingObject* self, PyObject* args)
     return PyImagingNew(ImagingEffectNoise(xsize, ysize, sigma));
 }
 
-static PyObject* 
+static PyObject*
 _effect_spread(ImagingObject* self, PyObject* args)
 {
     int dist;
@@ -2796,7 +2835,7 @@ _effect_spread(ImagingObject* self, PyObject* args)
 /* UTILITIES								*/
 /* -------------------------------------------------------------------- */
 
-static PyObject* 
+static PyObject*
 _crc32(PyObject* self, PyObject* args)
 {
     unsigned char* buffer;
@@ -2817,7 +2856,7 @@ _crc32(PyObject* self, PyObject* args)
     return Py_BuildValue("ii", (crc >> 16) & 0xFFFF, crc & 0xFFFF);
 }
 
-static PyObject* 
+static PyObject*
 _getcodecstatus(PyObject* self, PyObject* args)
 {
     int status;
@@ -2851,7 +2890,7 @@ _getcodecstatus(PyObject* self, PyObject* args)
 
 #ifdef WITH_DEBUG
 
-static PyObject* 
+static PyObject*
 _save_ppm(ImagingObject* self, PyObject* args)
 {
     char* filename;
@@ -2925,10 +2964,12 @@ static struct PyMethodDef methods[] = {
     {"fillband", (PyCFunction)_fillband, 1},
 
     {"setmode", (PyCFunction)im_setmode, 1},
-    
+
     {"getpalette", (PyCFunction)_getpalette, 1},
+    {"getpalettemode", (PyCFunction)_getpalettemode, 1},
     {"putpalette", (PyCFunction)_putpalette, 1},
     {"putpalettealpha", (PyCFunction)_putpalettealpha, 1},
+    {"putpalettealphas", (PyCFunction)_putpalettealphas, 1},
 
 #ifdef WITH_IMAGECHOPS
     /* Channel operations (ImageChops) */
@@ -3324,7 +3365,7 @@ static PyMethodDef functions[] = {
 #ifdef WITH_IMAGEPATH
     {"path", (PyCFunction)PyPath_Create, 1},
 #endif
-    
+
     /* Experimental arrow graphics stuff */
 #ifdef WITH_ARROW
     {"outline", (PyCFunction)PyOutline_Create, 1},
@@ -3361,6 +3402,13 @@ setup_module(PyObject* m) {
 #endif
 
 #ifdef HAVE_LIBZ
+#include "zlib.h"
+  /* zip encoding strategies */
+  PyModule_AddIntConstant(m, "DEFAULT_STRATEGY", Z_DEFAULT_STRATEGY);
+  PyModule_AddIntConstant(m, "FILTERED", Z_FILTERED);
+  PyModule_AddIntConstant(m, "HUFFMAN_ONLY", Z_HUFFMAN_ONLY);
+  PyModule_AddIntConstant(m, "RLE", Z_RLE);
+  PyModule_AddIntConstant(m, "FIXED", Z_FIXED);
   {
     extern const char* ImagingZipVersion(void);
     PyDict_SetItemString(d, "zlib_version", PyUnicode_FromString(ImagingZipVersion()));
diff --git a/encode.c b/encode.c
index 123a3dc79..f6191613f 100644
--- a/encode.c
+++ b/encode.c
@@ -445,10 +445,14 @@ PyImaging_ZipEncoderNew(PyObject* self, PyObject* args)
     char* mode;
     char* rawmode;
     int optimize = 0;
+    int compress_level = -1;
+    int compress_type = -1;
     char* dictionary = NULL;
     int dictionary_size = 0;
-    if (!PyArg_ParseTuple(args, "ss|i"PY_ARG_BYTES_LENGTH, &mode, &rawmode,
-                          &optimize, &dictionary, &dictionary_size))
+    if (!PyArg_ParseTuple(args, "ss|iii"PY_ARG_BYTES_LENGTH, &mode, &rawmode,
+                          &optimize,
+                          &compress_level, &compress_type,
+                          &dictionary, &dictionary_size))
         return NULL;
 
     /* Copy to avoid referencing Python's memory, but there's no mechanism to
@@ -477,6 +481,8 @@ PyImaging_ZipEncoderNew(PyObject* self, PyObject* args)
 	((ZIPSTATE*)encoder->state.context)->mode = ZIP_PNG_PALETTE;
 
     ((ZIPSTATE*)encoder->state.context)->optimize = optimize;
+    ((ZIPSTATE*)encoder->state.context)->compress_level = compress_level;
+    ((ZIPSTATE*)encoder->state.context)->compress_type = compress_type;
     ((ZIPSTATE*)encoder->state.context)->dictionary = dictionary;
     ((ZIPSTATE*)encoder->state.context)->dictionary_size = dictionary_size;
 
@@ -512,16 +518,16 @@ static unsigned int** get_qtables_arrays(PyObject* qtables) {
     PyObject* table_data;
     int i, j, num_tables;
     unsigned int **qarrays;
-    
+
     if (qtables == Py_None) {
         return NULL;
     }
-    
+
     if (!PySequence_Check(qtables)) {
         PyErr_SetString(PyExc_ValueError, "Invalid quantization tables");
         return NULL;
     }
-    
+
     tables = PySequence_Fast(qtables, "expected a sequence");
     num_tables = PySequence_Size(qtables);
     if (num_tables < 2 || num_tables > NUM_QUANT_TBLS) {
diff --git a/libImaging/Quant.c b/libImaging/Quant.c
index 5d8d13500..ff15ac01f 100644
--- a/libImaging/Quant.c
+++ b/libImaging/Quant.c
@@ -26,6 +26,7 @@
 #include <time.h>
 
 #include "Quant.h"
+#include "QuantOctree.h"
 
 #include "QuantDefines.h"
 #include "QuantHash.h"
@@ -1485,6 +1486,8 @@ ImagingQuantize(Imaging im, int colors, int mode, int kmeans)
     int result;
     unsigned long* newData;
     Imaging imOut;
+    int withAlpha = 0;
+    ImagingSectionCookie cookie;
 
     if (!im)
 	return ImagingError_ModeError();
@@ -1494,9 +1497,13 @@ ImagingQuantize(Imaging im, int colors, int mode, int kmeans)
         return (Imaging) ImagingError_ValueError("bad number of colors");
 
     if (strcmp(im->mode, "L") != 0 && strcmp(im->mode, "P") != 0 &&
-        strcmp(im->mode, "RGB"))
+        strcmp(im->mode, "RGB") != 0 && strcmp(im->mode, "RGBA") !=0)
         return ImagingError_ModeError();
 
+    /* only octree supports RGBA */
+    if (!strcmp(im->mode, "RGBA") && mode != 2)
+       return ImagingError_ModeError();
+
     p = malloc(sizeof(Pixel) * im->xsize * im->ysize);
     if (!p)
         return ImagingError_MemoryError();
@@ -1529,7 +1536,7 @@ ImagingQuantize(Imaging im, int colors, int mode, int kmeans)
                 p[i].c.b = pp[v*4+2];
             }
 
-    } else if (!strcmp(im->mode, "RGB")) {
+    } else if (!strcmp(im->mode, "RGB") || !strcmp(im->mode, "RGBA")) {
         /* true colour */
 
         for (i = y = 0; y < im->ysize; y++)
@@ -1541,6 +1548,8 @@ ImagingQuantize(Imaging im, int colors, int mode, int kmeans)
         return (Imaging) ImagingError_ValueError("internal error");
     }
 
+    ImagingSectionEnter(&cookie);
+
     switch (mode) {
     case 0:
         /* median cut */
@@ -1566,16 +1575,31 @@ ImagingQuantize(Imaging im, int colors, int mode, int kmeans)
             kmeans
             );
         break;
+    case 2:
+        if (!strcmp(im->mode, "RGBA")) {
+            withAlpha = 1; 
+        }
+        result = quantize_octree(
+            p,
+            im->xsize*im->ysize,
+            colors,
+            &palette,
+            &paletteLength,
+            &newData,
+            withAlpha
+            );
+        break;
     default:
         result = 0;
         break;
     }
 
     free(p);
+    ImagingSectionLeave(&cookie);
 
     if (result) {
-
         imOut = ImagingNew("P", im->xsize, im->ysize);
+        ImagingSectionEnter(&cookie);
 
         for (i = y = 0; y < im->ysize; y++)
             for (x=0; x < im->xsize; x++)
@@ -1589,7 +1613,11 @@ ImagingQuantize(Imaging im, int colors, int mode, int kmeans)
             *pp++ = palette[i].c.r;
             *pp++ = palette[i].c.g;
             *pp++ = palette[i].c.b;
-            *pp++ = 255;
+            if (withAlpha) {
+               *pp++ = palette[i].c.a;
+            } else {
+               *pp++ = 255;
+            }
         }
         for (; i < 256; i++) {
             *pp++ = 0;
@@ -1598,7 +1626,12 @@ ImagingQuantize(Imaging im, int colors, int mode, int kmeans)
             *pp++ = 255;
         }
 
+        if (withAlpha) {
+            strcpy(imOut->palette->mode, "RGBA");
+        }
+
         free(palette);
+        ImagingSectionLeave(&cookie);
 
         return imOut;
 
diff --git a/libImaging/QuantOctree.c b/libImaging/QuantOctree.c
new file mode 100644
index 000000000..fcdf9e0b0
--- /dev/null
+++ b/libImaging/QuantOctree.c
@@ -0,0 +1,454 @@
+/* Copyright (c) 2010 Oliver Tonnhofer <olt@bogosoft.com>, Omniscale
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+*/
+
+/*
+// This file implements a variation of the octree color quantization algorithm.
+*/
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "Quant.h"
+
+typedef struct _ColorBucket{
+   /* contains palette index when used for look up cube */
+   unsigned long count;
+   unsigned long r;
+   unsigned long g;
+   unsigned long b;
+   unsigned long a;
+} *ColorBucket;
+
+typedef struct _ColorCube{
+   unsigned int rBits, gBits, bBits, aBits;
+   unsigned int rWidth, gWidth, bWidth, aWidth;
+   unsigned int rOffset, gOffset, bOffset, aOffset;
+
+   long size;
+   ColorBucket buckets;
+} *ColorCube;
+
+#define MAX(a, b) (a)>(b) ? (a) : (b)
+
+static ColorCube
+new_color_cube(int r, int g, int b, int a) {
+   ColorCube cube;
+
+   cube = malloc(sizeof(struct _ColorCube));
+   if (!cube) return NULL;
+
+   cube->rBits = MAX(r, 0);
+   cube->gBits = MAX(g, 0);
+   cube->bBits = MAX(b, 0);
+   cube->aBits = MAX(a, 0);
+
+   /* the width of the cube for each dimension */
+   cube->rWidth = 1<<cube->rBits;
+   cube->gWidth = 1<<cube->gBits;
+   cube->bWidth = 1<<cube->bBits;
+   cube->aWidth = 1<<cube->aBits;
+
+   /* the offsets of each color */
+
+   cube->rOffset = cube->gBits + cube->bBits + cube->aBits;
+   cube->gOffset = cube->bBits + cube->aBits;
+   cube->bOffset = cube->aBits;
+   cube->aOffset = 0;
+
+   /* the number of color buckets */
+   cube->size = cube->rWidth * cube->gWidth * cube->bWidth * cube->aWidth;
+   cube->buckets = calloc(cube->size, sizeof(struct _ColorBucket));
+
+   if (!cube->buckets) {
+      free(cube);
+      return NULL;
+   }
+   return cube;
+}
+
+static void
+free_color_cube(ColorCube cube) {
+   if (cube != NULL) {
+      free(cube->buckets);
+      free(cube);
+   }
+}
+
+static long
+color_bucket_offset_pos(const ColorCube cube,
+   unsigned int r, unsigned int g, unsigned int b, unsigned int a)
+{
+   return r<<cube->rOffset | g<<cube->gOffset | b<<cube->bOffset | a<<cube->aOffset;
+}
+
+static long
+color_bucket_offset(const ColorCube cube, const Pixel *p) {
+   unsigned int r = p->c.r>>(8-cube->rBits);
+   unsigned int g = p->c.g>>(8-cube->gBits);
+   unsigned int b = p->c.b>>(8-cube->bBits);
+   unsigned int a = p->c.a>>(8-cube->aBits);
+   return color_bucket_offset_pos(cube, r, g, b, a);
+}
+
+static ColorBucket
+color_bucket_from_cube(const ColorCube cube, const Pixel *p) {
+   unsigned int offset = color_bucket_offset(cube, p);
+   return &cube->buckets[offset];
+}
+
+static void
+add_color_to_color_cube(const ColorCube cube, const Pixel *p) {
+   ColorBucket bucket = color_bucket_from_cube(cube, p);
+   bucket->count += 1;
+   bucket->r += p->c.r;
+   bucket->g += p->c.g;
+   bucket->b += p->c.b;
+   bucket->a += p->c.a;
+}
+
+static long
+count_used_color_buckets(const ColorCube cube) {
+   long usedBuckets = 0;
+   long i;
+   for (i=0; i < cube->size; i++) {
+      if (cube->buckets[i].count > 0) {
+         usedBuckets += 1;
+      }
+   }
+   return usedBuckets;
+}
+
+static void
+avg_color_from_color_bucket(const ColorBucket bucket, Pixel *dst) {
+   float count = bucket->count;
+   dst->c.r = (int)(bucket->r / count);
+   dst->c.g = (int)(bucket->g / count);
+   dst->c.b = (int)(bucket->b / count);
+   dst->c.a = (int)(bucket->a / count);
+}
+
+static int
+compare_bucket_count(const ColorBucket a, const ColorBucket b) {
+   return b->count - a->count;
+}
+
+static ColorBucket
+create_sorted_color_palette(const ColorCube cube) {
+   ColorBucket buckets;
+   buckets = malloc(sizeof(struct _ColorBucket)*cube->size);
+   if (!buckets) return NULL;
+   memcpy(buckets, cube->buckets, sizeof(struct _ColorBucket)*cube->size);
+
+   qsort(buckets, cube->size, sizeof(struct _ColorBucket),
+         (int (*)(void const *, void const *))&compare_bucket_count);
+
+   return buckets;
+}
+
+void add_bucket_values(ColorBucket src, ColorBucket dst) {
+   dst->count += src->count;
+   dst->r += src->r;
+   dst->g += src->g;
+   dst->b += src->b;
+   dst->a += src->a;
+}
+
+/* expand or shrink a given cube to level */
+static ColorCube copy_color_cube(const ColorCube cube,
+   int rBits, int gBits, int bBits, int aBits)
+{
+   unsigned int r, g, b, a;
+   long src_pos, dst_pos;
+   unsigned int src_reduce[4] = {0}, dst_reduce[4] = {0};
+   unsigned int width[4];
+   ColorCube result;
+
+   result = new_color_cube(rBits, gBits, bBits, aBits);
+   if (!result) return NULL;
+
+   if (cube->rBits > rBits) {
+      dst_reduce[0] = cube->rBits - result->rBits;
+      width[0] = cube->rWidth;
+   } else {
+      src_reduce[0] = result->rBits - cube->rBits;
+      width[0] = result->rWidth;
+   }
+   if (cube->gBits > gBits) {
+      dst_reduce[1] = cube->gBits - result->gBits;
+      width[1] = cube->gWidth;
+   } else {
+      src_reduce[1] = result->gBits - cube->gBits;
+      width[1] = result->gWidth;
+   }
+   if (cube->bBits > bBits) {
+      dst_reduce[2] = cube->bBits - result->bBits;
+      width[2] = cube->bWidth;
+   } else {
+      src_reduce[2] = result->bBits - cube->bBits;
+      width[2] = result->bWidth;
+   }
+   if (cube->aBits > aBits) {
+      dst_reduce[3] = cube->aBits - result->aBits;
+      width[3] = cube->aWidth;
+   } else {
+      src_reduce[3] = result->aBits - cube->aBits;
+      width[3] = result->aWidth;
+   }
+
+   for (r=0; r<width[0]; r++) {
+      for (g=0; g<width[1]; g++) {
+         for (b=0; b<width[2]; b++) {
+            for (a=0; a<width[3]; a++) {
+               src_pos = color_bucket_offset_pos(cube,
+                                               r>>src_reduce[0],
+                                               g>>src_reduce[1],
+                                               b>>src_reduce[2],
+                                               a>>src_reduce[3]);
+               dst_pos = color_bucket_offset_pos(result,
+                                               r>>dst_reduce[0],
+                                               g>>dst_reduce[1],
+                                               b>>dst_reduce[2],
+                                               a>>dst_reduce[3]);
+               add_bucket_values(
+                  &cube->buckets[src_pos],
+                  &result->buckets[dst_pos]
+               );
+            }
+         }
+      }
+   }
+   return result;
+}
+
+void
+subtract_color_buckets(ColorCube cube, ColorBucket buckets, long nBuckets) {
+   ColorBucket minuend, subtrahend;
+   long i;
+   Pixel p;
+   for (i=0; i<nBuckets; i++) {
+      subtrahend = &buckets[i];
+      avg_color_from_color_bucket(subtrahend, &p);
+      minuend = color_bucket_from_cube(cube, &p);
+      minuend->count -= subtrahend->count;
+      minuend->r -= subtrahend->r;
+      minuend->g -= subtrahend->g;
+      minuend->b -= subtrahend->b;
+      minuend->a -= subtrahend->a;
+   }
+}
+
+static void
+set_lookup_value(const ColorCube cube, const Pixel *p, long value) {
+   ColorBucket bucket = color_bucket_from_cube(cube, p);
+   bucket->count = value;
+}
+
+unsigned long
+lookup_color(const ColorCube cube, const Pixel *p) {
+   ColorBucket bucket = color_bucket_from_cube(cube, p);
+   return bucket->count;
+}
+
+void add_lookup_buckets(ColorCube cube, ColorBucket palette, long nColors, long offset) {
+   long i;
+   Pixel p;
+   for (i=offset; i<offset+nColors; i++) {
+      avg_color_from_color_bucket(&palette[i], &p);
+      set_lookup_value(cube, &p, i);
+   }
+}
+
+ColorBucket
+combined_palette(ColorBucket bucketsA, long nBucketsA, ColorBucket bucketsB, long nBucketsB) {
+   ColorBucket result;
+   result = malloc(sizeof(struct _ColorBucket)*(nBucketsA+nBucketsB));
+   memcpy(result, bucketsA, sizeof(struct _ColorBucket) * nBucketsA);
+   memcpy(&result[nBucketsA], bucketsB, sizeof(struct _ColorBucket) * nBucketsB);
+   return result;
+}
+
+static Pixel *
+create_palette_array(const ColorBucket palette, unsigned int paletteLength) {
+   Pixel *paletteArray;
+   unsigned int i;
+
+   paletteArray = malloc(sizeof(Pixel)*paletteLength);
+   if (!paletteArray) return NULL;
+
+   for (i=0; i<paletteLength; i++) {
+      avg_color_from_color_bucket(&palette[i], &paletteArray[i]);
+   }
+   return paletteArray;
+}
+
+static void
+map_image_pixels(const Pixel *pixelData,
+                 unsigned long nPixels,
+                 const ColorCube lookupCube,
+                 unsigned long *pixelArray)
+{
+   long i;
+   for (i=0; i<nPixels; i++) {
+      pixelArray[i] = lookup_color(lookupCube, &pixelData[i]);
+   }
+}
+
+const int CUBE_LEVELS[8]       = {4, 4, 4, 0, 2, 2, 2, 0};
+const int CUBE_LEVELS_ALPHA[8] = {3, 4, 3, 3, 2, 2, 2, 2};
+
+int quantize_octree(Pixel *pixelData,
+          unsigned long nPixels,
+          unsigned long nQuantPixels,
+          Pixel **palette,
+          unsigned long *paletteLength,
+          unsigned long **quantizedPixels,
+          int withAlpha)
+{
+   ColorCube fineCube = NULL;
+   ColorCube coarseCube = NULL;
+   ColorCube lookupCube = NULL;
+   ColorCube coarseLookupCube = NULL;
+   ColorBucket paletteBucketsCoarse = NULL;
+   ColorBucket paletteBucketsFine = NULL;
+   ColorBucket paletteBuckets = NULL;
+   unsigned long *qp = NULL;
+   long i;
+   long nCoarseColors, nFineColors, nAlreadySubtracted;
+   const int *cubeBits;
+
+   if (withAlpha) {
+       cubeBits = CUBE_LEVELS_ALPHA;
+   }
+   else {
+       cubeBits = CUBE_LEVELS;
+   }
+
+   /*
+   Create two color cubes, one fine grained with 8x16x8=1024
+   colors buckets and a coarse with 4x4x4=64 color buckets.
+   The coarse one guarantes that there are color buckets available for
+   the whole color range (assuming nQuantPixels > 64).
+
+   For a quantization to 256 colors all 64 coarse colors will be used
+   plus the 192 most used color buckets from the fine color cube.
+   The average of all colors within one bucket is used as the actual
+   color for that bucket.
+
+    For images with alpha the cubes gets a forth dimension,
+    8x16x8x8 and 4x4x4x4.
+   */
+
+   /* create fine cube */
+   fineCube = new_color_cube(cubeBits[0], cubeBits[1],
+                             cubeBits[2], cubeBits[3]);
+   if (!fineCube) goto error;
+   for (i=0; i<nPixels; i++) {
+      add_color_to_color_cube(fineCube, &pixelData[i]);
+   }
+
+   /* create coarse cube */
+   coarseCube = copy_color_cube(fineCube, cubeBits[4], cubeBits[5],
+                                          cubeBits[6], cubeBits[7]);
+   if (!coarseCube) goto error;
+   nCoarseColors = count_used_color_buckets(coarseCube);
+
+   /* limit to nQuantPixels */
+   if (nCoarseColors > nQuantPixels)
+      nCoarseColors = nQuantPixels;
+
+   /* how many space do we have in our palette for fine colors? */
+   nFineColors = nQuantPixels - nCoarseColors;
+
+   /* create fine color palette */
+   paletteBucketsFine = create_sorted_color_palette(fineCube);
+   if (!paletteBucketsFine) goto error;
+
+   /* remove the used fine colors from the coarse cube */
+   subtract_color_buckets(coarseCube, paletteBucketsFine, nFineColors);
+
+   /* did the substraction cleared one or more coarse bucket? */
+   while (nCoarseColors > count_used_color_buckets(coarseCube)) {
+      /* then we can use the free buckets for fine colors */
+      nAlreadySubtracted = nFineColors;
+      nCoarseColors = count_used_color_buckets(coarseCube);
+      nFineColors = nQuantPixels - nCoarseColors;
+      subtract_color_buckets(coarseCube, &paletteBucketsFine[nAlreadySubtracted],
+                             nFineColors-nAlreadySubtracted);
+   }
+
+   /* create our palette buckets with fine and coarse combined */
+   paletteBucketsCoarse = create_sorted_color_palette(coarseCube);
+   if (!paletteBucketsCoarse) goto error;
+   paletteBuckets = combined_palette(paletteBucketsCoarse, nCoarseColors,
+                                     paletteBucketsFine, nFineColors);
+
+   free(paletteBucketsFine);
+   paletteBucketsFine = NULL;
+   free(paletteBucketsCoarse);
+   paletteBucketsCoarse = NULL;
+
+   /* add all coarse colors to our coarse lookup cube. */
+   coarseLookupCube = new_color_cube(cubeBits[4], cubeBits[5],
+                                     cubeBits[6], cubeBits[7]);
+   if (!coarseLookupCube) goto error;
+   add_lookup_buckets(coarseLookupCube, paletteBuckets, nCoarseColors, 0);
+
+   /* expand coarse cube (64) to larger fine cube (4k). the value of each
+      coarse bucket is then present in the according 64 fine buckets. */
+   lookupCube = copy_color_cube(coarseLookupCube, cubeBits[0], cubeBits[1],
+                                                  cubeBits[2], cubeBits[3]);
+   if (!lookupCube) goto error;
+
+   /* add fine colors to the lookup cube */
+   add_lookup_buckets(lookupCube, paletteBuckets, nFineColors, nCoarseColors);
+
+   /* create result pixles and map palatte indices */
+   qp = malloc(sizeof(Pixel)*nPixels);
+   if (!qp) goto error;
+   map_image_pixels(pixelData, nPixels, lookupCube, qp);
+
+   /* convert palette buckets to RGB pixel palette */
+   *palette = create_palette_array(paletteBuckets, nQuantPixels);
+   if (!(*palette)) goto error;
+
+   *quantizedPixels = qp;
+   *paletteLength = nQuantPixels;
+
+   free_color_cube(coarseCube);
+   free_color_cube(fineCube);
+   free_color_cube(lookupCube);
+   free_color_cube(coarseLookupCube);
+   free(paletteBuckets);
+   return 1;
+
+error:
+   /* everything is initialized to NULL
+      so we are safe to call free */
+   free(qp);
+   free_color_cube(lookupCube);
+   free_color_cube(coarseLookupCube);
+   free(paletteBucketsCoarse);
+   free(paletteBucketsFine);
+   free_color_cube(coarseCube);
+   free_color_cube(fineCube);
+   return 0;
+}
diff --git a/libImaging/QuantOctree.h b/libImaging/QuantOctree.h
new file mode 100644
index 000000000..fd7b7dbb7
--- /dev/null
+++ b/libImaging/QuantOctree.h
@@ -0,0 +1,12 @@
+#ifndef __QUANT_OCTREE_H__
+#define __QUANT_OCTREE_H__
+
+int quantize_octree(Pixel *,
+          unsigned long,
+          unsigned long,
+          Pixel **,
+          unsigned long *,
+          unsigned long **,
+          int);
+
+#endif
\ No newline at end of file
diff --git a/libImaging/Zip.h b/libImaging/Zip.h
index d961407e3..e9d96b9e9 100644
--- a/libImaging/Zip.h
+++ b/libImaging/Zip.h
@@ -27,6 +27,11 @@ typedef struct {
 
     /* Optimize (max compression) SLOW!!! */
     int optimize;
+    
+    /* 0 no compression, 9 best compression, -1 default compression */
+    int compress_level;
+    /* compression strategy Z_XXX */
+    int compress_type;
 
     /* Predefined dictionary (experimental) */
     char* dictionary;
diff --git a/libImaging/ZipEncode.c b/libImaging/ZipEncode.c
index 19b2b7787..7b56e437e 100644
--- a/libImaging/ZipEncode.c
+++ b/libImaging/ZipEncode.c
@@ -26,6 +26,7 @@ ImagingZipEncode(Imaging im, ImagingCodecState state, UINT8* buf, int bytes)
 {
     ZIPSTATE* context = (ZIPSTATE*) state->context;
     int err;
+    int compress_level, compress_type;
     UINT8* ptr;
     int i, bpp, s, sum;
     ImagingSectionCookie cookie;
@@ -73,17 +74,25 @@ ImagingZipEncode(Imaging im, ImagingCodecState state, UINT8* buf, int bytes)
 	context->z_stream.next_in = 0;
 	context->z_stream.avail_in = 0;
 
+	compress_level = (context->optimize) ? Z_BEST_COMPRESSION
+					     : context->compress_level;
+
+	if (context->compress_type == -1) {
+	    compress_type = (context->mode == ZIP_PNG) ? Z_FILTERED
+						       : Z_DEFAULT_STRATEGY;
+	} else {
+	    compress_type = context->compress_type;
+	}
+
 	err = deflateInit2(&context->z_stream,
 			   /* compression level */
-			   (context->optimize) ? Z_BEST_COMPRESSION
-					       : Z_DEFAULT_COMPRESSION,
+			   compress_level,
 			   /* compression method */
 			   Z_DEFLATED,
 			   /* compression memory resources */
 			   15, 9,
 			   /* compression strategy (image data are filtered)*/
-			   (context->mode == ZIP_PNG) ? Z_FILTERED
-						      : Z_DEFAULT_STRATEGY);
+			   compress_type);
 	if (err < 0) {
 	    state->errcode = IMAGING_CODEC_CONFIG;
 	    return -1;
diff --git a/setup.py b/setup.py
index d05bada12..cd3e3380f 100644
--- a/setup.py
+++ b/setup.py
@@ -22,7 +22,7 @@ _LIB_IMAGING = (
     "Geometry", "GetBBox", "GifDecode", "GifEncode", "HexDecode",
     "Histo", "JpegDecode", "JpegEncode", "LzwDecode", "Matrix",
     "ModeFilter", "MspDecode", "Negative", "Offset", "Pack",
-    "PackDecode", "Palette", "Paste", "Quant", "QuantHash",
+    "PackDecode", "Palette", "Paste", "Quant", "QuantOctree", "QuantHash",
     "QuantHeap", "PcdDecode", "PcxDecode", "PcxEncode", "Point",
     "RankFilter", "RawDecode", "RawEncode", "Storage", "SunRleDecode",
     "TgaRleDecode", "Unpack", "UnpackYCC", "UnsharpMask", "XbmDecode",