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Image-Leptonica-0.04
River stage zero No dependents
/ Image::Leptonica::Func::graymorph

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.