#
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# The Python Imaging Library.
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# $Id$
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#
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# transform wrappers
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#
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# History:
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# 2002-04-08 fl Created
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#
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# Copyright (c) 2002 by Secret Labs AB
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# Copyright (c) 2002 by Fredrik Lundh
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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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import Image
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class Transform(Image.ImageTransformHandler):
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def __init__(self, data):
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self.data = data
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def getdata(self):
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return self.method, self.data
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def transform(self, size, image, **options):
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# can be overridden
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method, data = self.getdata()
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return image.transform(size, method, data, **options)
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##
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# Define an affine image transform.
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# <p>
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# This function takes a 6-tuple (<i>a, b, c, d, e, f</i>) which
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# contain the first two rows from an affine transform matrix. For
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# each pixel (<i>x, y</i>) in the output image, the new value is
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# taken from a position (a <i>x</i> + b <i>y</i> + c,
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# d <i>x</i> + e <i>y</i> + f) in the input image, rounded to
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# nearest pixel.
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# <p>
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# This function can be used to scale, translate, rotate, and shear the
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# original image.
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#
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# @def AffineTransform(matrix)
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# @param matrix A 6-tuple (<i>a, b, c, d, e, f</i>) containing
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# the first two rows from an affine transform matrix.
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# @see Image#Image.transform
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class AffineTransform(Transform):
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method = Image.AFFINE
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##
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# Define a transform to extract a subregion from an image.
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# <p>
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# Maps a rectangle (defined by two corners) from the image to a
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# rectangle of the given size. The resulting image will contain
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# data sampled from between the corners, such that (<i>x0, y0</i>)
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# in the input image will end up at (0,0) in the output image,
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# and (<i>x1, y1</i>) at <i>size</i>.
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# <p>
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# This method can be used to crop, stretch, shrink, or mirror an
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# arbitrary rectangle in the current image. It is slightly slower than
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# <b>crop</b>, but about as fast as a corresponding <b>resize</b>
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# operation.
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#
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# @def ExtentTransform(bbox)
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# @param bbox A 4-tuple (<i>x0, y0, x1, y1</i>) which specifies
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# two points in the input image's coordinate system.
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# @see Image#Image.transform
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class ExtentTransform(Transform):
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method = Image.EXTENT
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##
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# Define an quad image transform.
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# <p>
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# Maps a quadrilateral (a region defined by four corners) from the
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# image to a rectangle of the given size.
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#
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# @def QuadTransform(xy)
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# @param xy An 8-tuple (<i>x0, y0, x1, y1, x2, y2, y3, y3</i>) which
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# contain the upper left, lower left, lower right, and upper right
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# corner of the source quadrilateral.
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# @see Image#Image.transform
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class QuadTransform(Transform):
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method = Image.QUAD
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##
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# Define an mesh image transform. A mesh transform consists of one
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# or more individual quad transforms.
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#
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# @def MeshTransform(data)
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# @param data A list of (bbox, quad) tuples.
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# @see Image#Image.transform
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class MeshTransform(Transform):
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method = Image.MESH
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