Merge pull request #476 from wiredfool/cffi-pixelaccess

Cffi PixelAccess object, Uint16 support in PixelAccess

.travis.yml

@@ -10,7 +10,10 @@ python:
   - 3.2
   - 3.3
 
-install: "sudo apt-get -qq install libfreetype6-dev liblcms2-dev libwebp-dev python-qt4 ghostscript"
+install: 
+  - "sudo apt-get -qq install libfreetype6-dev liblcms2-dev libwebp-dev python-qt4 ghostscript libffi-dev"
+  - "pip install cffi"
+
 
 script:
   - python setup.py clean

PIL/Image.py

@@ -100,6 +100,13 @@ def __getattr__(self, id):
 import collections
 import numbers
 
+# works everywhere, win for pypy, not cpython
+USE_CFFI_ACCESS = hasattr(sys, 'pypy_version_info')  
+try:
+    import cffi
+    HAS_CFFI=True
+except:
+    HAS_CFFI=False
 
 def isImageType(t):
     """
@@ -468,6 +475,7 @@ def __init__(self):
         self.info = {}
         self.category = NORMAL
         self.readonly = 0
+        self.pyaccess = None
 
     def _new(self, im):
         new = Image()
@@ -492,6 +500,7 @@ def _new(self, im):
     def _copy(self):
         self.load()
         self.im = self.im.copy()
+        self.pyaccess = None
         self.readonly = 0
 
     def _dump(self, file=None, format=None):
@@ -645,6 +654,13 @@ def load(self):
                 self.palette.mode = "RGBA"
 
         if self.im:
+            if HAS_CFFI and USE_CFFI_ACCESS:
+                if self.pyaccess:
+                    return self.pyaccess
+                from PIL import PyAccess
+                self.pyaccess = PyAccess.new(self, self.readonly)
+                if self.pyaccess:
+                    return self.pyaccess
             return self.im.pixel_access(self.readonly)
 
     def verify(self):
@@ -976,6 +992,8 @@ def getpixel(self, xy):
         """
 
         self.load()
+        if self.pyaccess:
+            return self.pyaccess.getpixel(xy)
         return self.im.getpixel(xy)
 
     def getprojection(self):
@@ -1186,12 +1204,14 @@ def putalpha(self, alpha):
                 mode = getmodebase(self.mode) + "A"
                 try:
                     self.im.setmode(mode)
+                    self.pyaccess = None
                 except (AttributeError, ValueError):
                     # do things the hard way
                     im = self.im.convert(mode)
                     if im.mode not in ("LA", "RGBA"):
                         raise ValueError # sanity check
                     self.im = im
+                    self.pyaccess = None
                 self.mode = self.im.mode
             except (KeyError, ValueError):
                 raise ValueError("illegal image mode")
@@ -1292,7 +1312,11 @@ def putpixel(self, xy, value):
         self.load()
         if self.readonly:
             self._copy()
-
+            self.pyaccess = None
+            self.load()
+
+        if self.pyaccess: 
+            return self.pyaccess.putpixel(xy,value)
         return self.im.putpixel(xy, value)
 
     def resize(self, size, resample=NEAREST):
@@ -1593,6 +1617,7 @@ def thumbnail(self, size, resample=NEAREST):
         self.size = size
 
         self.readonly = 0
+        self.pyaccess = None
 
     # FIXME: the different tranform methods need further explanation
     # instead of bloating the method docs, add a separate chapter.

PIL/PyAccess.py

@@ -0,0 +1,297 @@
+#
+# The Python Imaging Library
+# Pillow fork
+#
+# Python implementation of the PixelAccess Object
+#
+# Copyright (c) 1997-2009 by Secret Labs AB.  All rights reserved.
+# Copyright (c) 1995-2009 by Fredrik Lundh.
+# Copyright (c) 2013 Eric Soroos
+#
+# See the README file for information on usage and redistribution
+#
+
+# Notes:
+#
+#  * Implements the pixel access object following Access.
+#  * Does not implement the line functions, as they don't appear to be used
+#  * Taking only the tuple form, which is used from python.
+#    * Fill.c uses the integer form, but it's still going to use the old Access.c implementation.
+#
+
+from __future__ import print_function
+
+from cffi import FFI
+import sys
+
+DEBUG = 0
+
+defs = """
+struct Pixel_RGBA {
+    unsigned char r,g,b,a;
+};
+struct Pixel_I16 {
+    unsigned char l,r;
+};
+"""
+ffi = FFI()
+ffi.cdef(defs)
+
+
+class PyAccess(object):
+
+    def __init__(self, img, readonly = False):
+        vals = dict(img.im.unsafe_ptrs)
+        self.readonly = readonly
+        self.image8 = ffi.cast('unsigned char **', vals['image8'])
+        self.image32 = ffi.cast('int **', vals['image32'])
+        self.image = ffi.cast('unsigned char **', vals['image'])
+        self.xsize = vals['xsize']
+        self.ysize = vals['ysize']
+
+        if DEBUG:
+            print (vals)
+        self._post_init()
+
+    def _post_init(): pass
+
+    def __setitem__(self, xy, color):
+        """
+        Modifies the pixel at x,y. The color is given as a single
+        numerical value for single band images, and a tuple for
+        multi-band images
+
+        :param xy: The pixel coordinate, given as (x, y).
+        :param value: The pixel value.                
+        """
+        if self.readonly: raise ValueError('Attempt to putpixel a read only image') 
+        (x,y) = self.check_xy(xy)
+        return self.set_pixel(x,y,color)
+
+    def __getitem__(self, xy):
+        """
+        Returns the pixel at x,y. The pixel is returned as a single
+        value for single band images or a tuple for multiple band
+        images
+
+        :param xy: The pixel coordinate, given as (x, y).
+        """
+
+        (x,y) = self.check_xy(xy)
+        return self.get_pixel(x,y)
+
+    putpixel = __setitem__
+    getpixel = __getitem__
+
+    def check_xy(self, xy):
+        (x,y) = xy
+        if not (0 <= x < self.xsize and 0 <= y < self.ysize):
+            raise ValueError('pixel location out of range')
+        return xy
+
+class _PyAccess32_2(PyAccess):
+    """ PA, LA, stored in first and last bytes of a 32 bit word """
+    def _post_init(self, *args, **kwargs):
+        self.pixels = ffi.cast("struct Pixel_RGBA **", self.image32)
+
+    def get_pixel(self, x,y):
+        pixel = self.pixels[y][x]
+        return (pixel.r, pixel.a)
+
+    def set_pixel(self, x,y, color):
+        pixel = self.pixels[y][x]
+        # tuple
+        pixel.r = min(color[0],255)
+        pixel.a = min(color[1],255)
+
+class _PyAccess32_3(PyAccess):
+    """ RGB and friends, stored in the first three bytes of a 32 bit word """
+
+    def _post_init(self, *args, **kwargs):
+        self.pixels = ffi.cast("struct Pixel_RGBA **", self.image32)
+
+    def get_pixel(self, x,y):
+        pixel = self.pixels[y][x]
+        return (pixel.r, pixel.g, pixel.b)
+
+    def set_pixel(self, x,y, color):
+        pixel = self.pixels[y][x]
+        # tuple
+        pixel.r = min(color[0],255)
+        pixel.g = min(color[1],255)
+        pixel.b = min(color[2],255)
+
+class _PyAccess32_4(PyAccess):
+    """ RGBA etc, all 4 bytes of a 32 bit word """
+    def _post_init(self, *args, **kwargs):
+        self.pixels = ffi.cast("struct Pixel_RGBA **", self.image32)
+
+    def get_pixel(self, x,y):
+        pixel = self.pixels[y][x]
+        return (pixel.r, pixel.g, pixel.b, pixel.a)
+
+    def set_pixel(self, x,y, color):
+        pixel = self.pixels[y][x]
+        # tuple
+        pixel.r = min(color[0],255)
+        pixel.g = min(color[1],255)
+        pixel.b = min(color[2],255)
+        pixel.a = min(color[3],255)
+
+
+class _PyAccess8(PyAccess):
+    """ 1, L, P, 8 bit images stored as uint8 """
+    def _post_init(self, *args, **kwargs):
+        self.pixels = self.image8
+
+    def get_pixel(self, x,y):
+        return self.pixels[y][x]
+
+    def set_pixel(self, x,y, color):
+        try:
+            # integer
+            self.pixels[y][x] = min(color,255)
+        except:
+            # tuple
+            self.pixels[y][x] = min(color[0],255)
+
+class _PyAccessI16_N(PyAccess):
+    """ I;16 access, native bitendian without conversion """
+    def _post_init(self, *args, **kwargs):
+        self.pixels = ffi.cast('unsigned short **', self.image)
+
+    def get_pixel(self, x,y):
+        return self.pixels[y][x]
+
+    def set_pixel(self, x,y, color):
+        try:
+            # integer
+            self.pixels[y][x] = min(color, 65535)
+        except:
+            # tuple
+            self.pixels[y][x] = min(color[0], 65535)
+
+class _PyAccessI16_L(PyAccess):
+    """ I;16L access, with conversion """
+    def _post_init(self, *args, **kwargs):
+        self.pixels = ffi.cast('struct Pixel_I16 **', self.image)
+
+    def get_pixel(self, x,y):
+        pixel = self.pixels[y][x]
+        return pixel.l + pixel.r * 256
+
+    def set_pixel(self, x,y, color):
+        pixel = self.pixels[y][x]
+        try:
+            color = min(color, 65535)
+        except:
+            color = min(color[0], 65535)
+
+        pixel.l = color & 0xFF
+        pixel.r = color >> 8
+
+class _PyAccessI16_B(PyAccess):
+    """ I;16B access, with conversion """
+    def _post_init(self, *args, **kwargs):
+        self.pixels = ffi.cast('struct Pixel_I16 **', self.image)
+
+    def get_pixel(self, x,y):
+        pixel = self.pixels[y][x]
+        return pixel.l *256  + pixel.r
+
+    def set_pixel(self, x,y, color):
+        pixel = self.pixels[y][x]
+        try:
+            color = min(color, 65535)
+        except:
+            color = min(color[0], 65535)
+
+        pixel.l = color >> 8
+        pixel.r = color & 0xFF
+
+class _PyAccessI32_N(PyAccess):
+    """ Signed Int32 access, native endian """
+    def _post_init(self, *args, **kwargs):
+        self.pixels = self.image32
+
+    def get_pixel(self, x,y):
+        return self.pixels[y][x]
+
+    def set_pixel(self, x,y, color):
+        self.pixels[y][x] = color
+
+class _PyAccessI32_Swap(PyAccess):
+    """ I;32L/B access, with byteswapping conversion """
+    def _post_init(self, *args, **kwargs):
+        self.pixels = self.image32
+
+    def reverse(self, i):
+        orig = ffi.new('int *', i)
+        chars = ffi.cast('unsigned char *', orig)
+        chars[0],chars[1],chars[2],chars[3] = chars[3], chars[2],chars[1],chars[0]
+        return ffi.cast('int *', chars)[0]
+
+    def get_pixel(self, x,y):
+        return self.reverse(self.pixels[y][x])
+
+    def set_pixel(self, x,y, color):
+        self.pixels[y][x] = self.reverse(color)
+
+class _PyAccessF(PyAccess):
+    """ 32 bit float access """
+    def _post_init(self, *args, **kwargs):
+        self.pixels = ffi.cast('float **', self.image32)
+
+    def get_pixel(self, x,y):
+        return self.pixels[y][x]
+
+    def set_pixel(self, x,y, color):
+        try:
+            # not a tuple
+            self.pixels[y][x] = color
+        except:
+            # tuple
+            self.pixels[y][x] = color[0]
+
+
+mode_map = {'1': _PyAccess8,
+            'L': _PyAccess8,
+            'P': _PyAccess8,
+            'LA': _PyAccess32_2,
+            'PA': _PyAccess32_2,
+            'RGB': _PyAccess32_3,
+            'LAB': _PyAccess32_3,
+            'YCbCr': _PyAccess32_3,
+            'RGBA': _PyAccess32_4,
+            'RGBa': _PyAccess32_4,
+            'RGBX': _PyAccess32_4,
+            'CMYK': _PyAccess32_4,
+            'F': _PyAccessF,
+            'I': _PyAccessI32_N,
+            }
+
+if sys.byteorder == 'little':
+    mode_map['I;16'] = _PyAccessI16_N
+    mode_map['I;16L'] = _PyAccessI16_N
+    mode_map['I;16B'] = _PyAccessI16_B
+
+    mode_map['I;32L'] = _PyAccessI32_N
+    mode_map['I;32B'] = _PyAccessI32_Swap
+else:
+    mode_map['I;16'] = _PyAccessI16_L
+    mode_map['I;16L'] = _PyAccessI16_L
+    mode_map['I;16B'] = _PyAccessI16_N
+
+    mode_map['I;32L'] = _PyAccessI32_Swap
+    mode_map['I;32B'] = _PyAccessI32_N
+
+def new(img, readonly=False):
+
+    access_type = mode_map.get(img.mode, None)
+    if not access_type:
+        if DEBUG: print ("PyAccess Not Implemented: %s" % img.mode)
+        return None
+    if DEBUG: print ("New PyAccess: %s" % img.mode)
+    return access_type(img, readonly)
+
+