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