NAME
Image::Leptonica::Func::graymorph
VERSION
version 0.04
graymorph.c
graymorph.c
Top-level binary morphological operations (van Herk / Gil-Werman)
PIX *pixErodeGray()
PIX *pixDilateGray()
PIX *pixOpenGray()
PIX *pixCloseGray()
Special operations for 1x3, 3x1 and 3x3 Sels (direct)
PIX *pixErodeGray3()
PIX *pixDilateGray3()
PIX *pixOpenGray3()
PIX *pixCloseGray3()
Method: Algorithm by van Herk and Gil and Werman, 1992
Measured speed of the vH/G-W implementation is about 1 output
pixel per 120 PIII clock cycles, for a horizontal or vertical
erosion or dilation. The computation time doubles for opening
or closing, or for a square SE, as expected, and is independent
of the size of the SE.
A faster implementation can be made directly for brick Sels
of maximum size 3. We unroll the computation for sets of 8 bytes.
It needs to be called explicitly; the general functions do not
default for the size 3 brick Sels.FUNCTIONS
pixCloseGray
PIX * pixCloseGray ( PIX *pixs, l_int32 hsize, l_int32 vsize )
pixCloseGray()
Input: pixs
hsize (of Sel; must be odd; origin implicitly in center)
vsize (ditto)
Return: pixd
Notes:
(1) Sel is a brick with all elements being hits
(2) If hsize = vsize = 1, just returns a copy.pixCloseGray3
PIX * pixCloseGray3 ( PIX *pixs, l_int32 hsize, l_int32 vsize )
pixCloseGray3()
Input: pixs (8 bpp, not cmapped)
hsize (1 or 3)
vsize (1 or 3)
Return: pixd, or null on error
Notes:
(1) Special case for 1x3, 3x1 or 3x3 brick sel (all hits)
(2) If hsize = vsize = 1, just returns a copy.pixDilateGray
PIX * pixDilateGray ( PIX *pixs, l_int32 hsize, l_int32 vsize )
pixDilateGray()
Input: pixs
hsize (of Sel; must be odd; origin implicitly in center)
vsize (ditto)
Return: pixd
Notes:
(1) Sel is a brick with all elements being hits
(2) If hsize = vsize = 1, just returns a copy.pixDilateGray3
PIX * pixDilateGray3 ( PIX *pixs, l_int32 hsize, l_int32 vsize )
pixDilateGray3()
Input: pixs (8 bpp, not cmapped)
hsize (1 or 3)
vsize (1 or 3)
Return: pixd, or null on error
Notes:
(1) Special case for 1x3, 3x1 or 3x3 brick sel (all hits)
(2) If hsize = vsize = 1, just returns a copy.pixErodeGray
PIX * pixErodeGray ( PIX *pixs, l_int32 hsize, l_int32 vsize )
pixErodeGray()
Input: pixs
hsize (of Sel; must be odd; origin implicitly in center)
vsize (ditto)
Return: pixd
Notes:
(1) Sel is a brick with all elements being hits
(2) If hsize = vsize = 1, just returns a copy.pixErodeGray3
PIX * pixErodeGray3 ( PIX *pixs, l_int32 hsize, l_int32 vsize )
pixErodeGray3()
Input: pixs (8 bpp, not cmapped)
hsize (1 or 3)
vsize (1 or 3)
Return: pixd, or null on error
Notes:
(1) Special case for 1x3, 3x1 or 3x3 brick sel (all hits)
(2) If hsize = vsize = 1, just returns a copy.
(3) It would be nice not to add a border, but it is required
if we want the same results as from the general case.
We add 4 bytes on the left to speed up the copying, and
8 bytes at the right and bottom to allow unrolling of
the computation of 8 pixels.pixOpenGray
PIX * pixOpenGray ( PIX *pixs, l_int32 hsize, l_int32 vsize )
pixOpenGray()
Input: pixs
hsize (of Sel; must be odd; origin implicitly in center)
vsize (ditto)
Return: pixd
Notes:
(1) Sel is a brick with all elements being hits
(2) If hsize = vsize = 1, just returns a copy.pixOpenGray3
PIX * pixOpenGray3 ( PIX *pixs, l_int32 hsize, l_int32 vsize )
pixOpenGray3()
Input: pixs (8 bpp, not cmapped)
hsize (1 or 3)
vsize (1 or 3)
Return: pixd, or null on error
Notes:
(1) Special case for 1x3, 3x1 or 3x3 brick sel (all hits)
(2) If hsize = vsize = 1, just returns a copy.
(3) It would be nice not to add a border, but it is required
to get the same results as for the general case.AUTHOR
Zakariyya Mughal <zmughal@cpan.org>
COPYRIGHT AND LICENSE
This software is copyright (c) 2014 by Zakariyya Mughal.
This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.