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ImageMath.py 7.3KB

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  1. #
  2. # The Python Imaging Library
  3. # $Id$
  4. #
  5. # a simple math add-on for the Python Imaging Library
  6. #
  7. # History:
  8. # 1999-02-15 fl Original PIL Plus release
  9. # 2005-05-05 fl Simplified and cleaned up for PIL 1.1.6
  10. # 2005-09-12 fl Fixed int() and float() for Python 2.4.1
  11. #
  12. # Copyright (c) 1999-2005 by Secret Labs AB
  13. # Copyright (c) 2005 by Fredrik Lundh
  14. #
  15. # See the README file for information on usage and redistribution.
  16. #
  17. from . import Image, _imagingmath
  18. from ._util import py3
  19. try:
  20. import builtins
  21. except ImportError:
  22. import __builtin__
  23. builtins = __builtin__
  24. VERBOSE = 0
  25. def _isconstant(v):
  26. return isinstance(v, (int, float))
  27. class _Operand(object):
  28. """Wraps an image operand, providing standard operators"""
  29. def __init__(self, im):
  30. self.im = im
  31. def __fixup(self, im1):
  32. # convert image to suitable mode
  33. if isinstance(im1, _Operand):
  34. # argument was an image.
  35. if im1.im.mode in ("1", "L"):
  36. return im1.im.convert("I")
  37. elif im1.im.mode in ("I", "F"):
  38. return im1.im
  39. else:
  40. raise ValueError("unsupported mode: %s" % im1.im.mode)
  41. else:
  42. # argument was a constant
  43. if _isconstant(im1) and self.im.mode in ("1", "L", "I"):
  44. return Image.new("I", self.im.size, im1)
  45. else:
  46. return Image.new("F", self.im.size, im1)
  47. def apply(self, op, im1, im2=None, mode=None):
  48. im1 = self.__fixup(im1)
  49. if im2 is None:
  50. # unary operation
  51. out = Image.new(mode or im1.mode, im1.size, None)
  52. im1.load()
  53. try:
  54. op = getattr(_imagingmath, op + "_" + im1.mode)
  55. except AttributeError:
  56. raise TypeError("bad operand type for '%s'" % op)
  57. _imagingmath.unop(op, out.im.id, im1.im.id)
  58. else:
  59. # binary operation
  60. im2 = self.__fixup(im2)
  61. if im1.mode != im2.mode:
  62. # convert both arguments to floating point
  63. if im1.mode != "F":
  64. im1 = im1.convert("F")
  65. if im2.mode != "F":
  66. im2 = im2.convert("F")
  67. if im1.mode != im2.mode:
  68. raise ValueError("mode mismatch")
  69. if im1.size != im2.size:
  70. # crop both arguments to a common size
  71. size = (min(im1.size[0], im2.size[0]), min(im1.size[1], im2.size[1]))
  72. if im1.size != size:
  73. im1 = im1.crop((0, 0) + size)
  74. if im2.size != size:
  75. im2 = im2.crop((0, 0) + size)
  76. out = Image.new(mode or im1.mode, size, None)
  77. else:
  78. out = Image.new(mode or im1.mode, im1.size, None)
  79. im1.load()
  80. im2.load()
  81. try:
  82. op = getattr(_imagingmath, op + "_" + im1.mode)
  83. except AttributeError:
  84. raise TypeError("bad operand type for '%s'" % op)
  85. _imagingmath.binop(op, out.im.id, im1.im.id, im2.im.id)
  86. return _Operand(out)
  87. # unary operators
  88. def __bool__(self):
  89. # an image is "true" if it contains at least one non-zero pixel
  90. return self.im.getbbox() is not None
  91. if not py3:
  92. # Provide __nonzero__ for pre-Py3k
  93. __nonzero__ = __bool__
  94. del __bool__
  95. def __abs__(self):
  96. return self.apply("abs", self)
  97. def __pos__(self):
  98. return self
  99. def __neg__(self):
  100. return self.apply("neg", self)
  101. # binary operators
  102. def __add__(self, other):
  103. return self.apply("add", self, other)
  104. def __radd__(self, other):
  105. return self.apply("add", other, self)
  106. def __sub__(self, other):
  107. return self.apply("sub", self, other)
  108. def __rsub__(self, other):
  109. return self.apply("sub", other, self)
  110. def __mul__(self, other):
  111. return self.apply("mul", self, other)
  112. def __rmul__(self, other):
  113. return self.apply("mul", other, self)
  114. def __truediv__(self, other):
  115. return self.apply("div", self, other)
  116. def __rtruediv__(self, other):
  117. return self.apply("div", other, self)
  118. def __mod__(self, other):
  119. return self.apply("mod", self, other)
  120. def __rmod__(self, other):
  121. return self.apply("mod", other, self)
  122. def __pow__(self, other):
  123. return self.apply("pow", self, other)
  124. def __rpow__(self, other):
  125. return self.apply("pow", other, self)
  126. if not py3:
  127. # Provide __div__ and __rdiv__ for pre-Py3k
  128. __div__ = __truediv__
  129. __rdiv__ = __rtruediv__
  130. del __truediv__
  131. del __rtruediv__
  132. # bitwise
  133. def __invert__(self):
  134. return self.apply("invert", self)
  135. def __and__(self, other):
  136. return self.apply("and", self, other)
  137. def __rand__(self, other):
  138. return self.apply("and", other, self)
  139. def __or__(self, other):
  140. return self.apply("or", self, other)
  141. def __ror__(self, other):
  142. return self.apply("or", other, self)
  143. def __xor__(self, other):
  144. return self.apply("xor", self, other)
  145. def __rxor__(self, other):
  146. return self.apply("xor", other, self)
  147. def __lshift__(self, other):
  148. return self.apply("lshift", self, other)
  149. def __rshift__(self, other):
  150. return self.apply("rshift", self, other)
  151. # logical
  152. def __eq__(self, other):
  153. return self.apply("eq", self, other)
  154. def __ne__(self, other):
  155. return self.apply("ne", self, other)
  156. def __lt__(self, other):
  157. return self.apply("lt", self, other)
  158. def __le__(self, other):
  159. return self.apply("le", self, other)
  160. def __gt__(self, other):
  161. return self.apply("gt", self, other)
  162. def __ge__(self, other):
  163. return self.apply("ge", self, other)
  164. # conversions
  165. def imagemath_int(self):
  166. return _Operand(self.im.convert("I"))
  167. def imagemath_float(self):
  168. return _Operand(self.im.convert("F"))
  169. # logical
  170. def imagemath_equal(self, other):
  171. return self.apply("eq", self, other, mode="I")
  172. def imagemath_notequal(self, other):
  173. return self.apply("ne", self, other, mode="I")
  174. def imagemath_min(self, other):
  175. return self.apply("min", self, other)
  176. def imagemath_max(self, other):
  177. return self.apply("max", self, other)
  178. def imagemath_convert(self, mode):
  179. return _Operand(self.im.convert(mode))
  180. ops = {}
  181. for k, v in list(globals().items()):
  182. if k[:10] == "imagemath_":
  183. ops[k[10:]] = v
  184. def eval(expression, _dict={}, **kw):
  185. """
  186. Evaluates an image expression.
  187. :param expression: A string containing a Python-style expression.
  188. :param options: Values to add to the evaluation context. You
  189. can either use a dictionary, or one or more keyword
  190. arguments.
  191. :return: The evaluated expression. This is usually an image object, but can
  192. also be an integer, a floating point value, or a pixel tuple,
  193. depending on the expression.
  194. """
  195. # build execution namespace
  196. args = ops.copy()
  197. args.update(_dict)
  198. args.update(kw)
  199. for k, v in list(args.items()):
  200. if hasattr(v, "im"):
  201. args[k] = _Operand(v)
  202. out = builtins.eval(expression, args)
  203. try:
  204. return out.im
  205. except AttributeError:
  206. return out