remove_ghost

Name

remove_ghost, remove_inv_ghost, mark_ghost, mark_inv_ghost - remove (or mark) "ghost" objects from (or in) binary image

Syntax

 #include <xite/binarize.h>

 int remove_ghost( IBAND segmented,
    IBAND original, IBAND outband,
    int val_step_threshold );
 int remove_inv_ghost( IBAND segmented,
    IBAND original, IBAND outband,
    int val_step_threshold );
 int mark_ghost( IBAND segmented,
    IBAND original, IBAND outband,
    int val_step_threshold );
 int mark_inv_ghost( IBAND segmented,
    IBAND original, IBAND outband,
    int val_step_threshold );

Description

The original gray scale image original and a binarized version segmented are input to the routine.

remove_ghost: First, inband is copied to outband. For all 4-connected black objects in outband, the average gradient magnitude value at the edge of the object is calculated. Objects having an average gradient below the threshold value val_step_threshold are removed from outband.
remove_inv_ghost: Works like remove_ghost on 4-connected white objects.
mark_ghost: Works like remove_ghost , but instead of removing an object, it is colored (255 - avg_grad), where avg_grad is the average gradient value on the edge of the object. It can then be thresholded manually to give the final binary image.
mark_inv_ghost: Combination of mark_ghost and remove_inv_ghost. Works like remove_inv_ghost , but instead of removing an object, it is colored avg_grad, where avg_grad is the average gradient value on the edge of the object.

Restrictions

Works on unsigned byte bands.

Return value

 0 : ok
 1 : Bad pixel type for segmented
 2 : Bad pixel type for original
 3 : Bad pixel type for outband

References

S.D. Yanowitz & A.M. Bruckstein: "A New Method for Image Segmentation", Comput. Vision Graphics Image Proc., vol 46, no 1, pp 82-95, April 1989.

Files

src/binarize/remove_ghost.c

Author

Řivind Due Trier

Id

$Id: remove_ghost.c,v 1.18 1997/01/29 10:37:42 svein Exp $