NAME

     maximum_filter - typically applied to  an  image  to  remove
     negative outlier noise.

SYNOPSIS

      #include <CVIPtoolkit.h>
      #include <CVIPdef.h>
      #include <CVIPspfltr.h>
      #include <float.h>

     Image *maximum_filter(Image *imageP, int mask_size)
           <imageP> - pointer to Image structure.
           <mask_size> - NxN is the size of the filtering window.

PATH

     $CVIPHOME/SPATIALFILTER/spatial_filter.c

OPTIONS

     None.

DESCRIPTION

     Returns the maximum value of the set of pixels contained  in
     the   N  x  N filter window. Size of filter should be an odd
     integer limited from < 3 - 31 >.

TIPS

     Works best on  images  containing  negative  outlier  noise.
     This filter will brighten the appearance of the image.  Keep
     mask size small to minimize blurring.

DIAGNOSTICS

     Returns a pointer to the modified Image  structure  on  suc-
     cess.  Returns a NULL pointer if the input Image datatype is
     not CVIP_BYTE and can't be cast to CVIP_FLOAT.

EXAMPLE

      #include <CVIPtoolkit.h>
      #include <CVIPimage.h>
      #include <CVIPdef.h>
      #include <CVIPspfltr.h>
      #include <CVIPconvert.h>
      #include <CVIPview.h>
      #define VIEWER "picture"
      #define VIDEO_APP "SunVideo &"

      void main()
      {
      Image *cvipImage;
      IMAGE_FORMAT format;
      char *inputfile,*outputfile;

      setDisplay_Image(VIEWER, "Default");
      print_CVIP("\n\t\tEnter the  Input File Name:  ");
      inputfile =(char *) getString_CVIP();
      format = getFormat_CVIP(inputfile);
      cvipImage = read_Image(inputfile, 1);
      view_Image(cvipImage, inputfile);
      free(inputfile);
      /* the following call replaces each pixel value
      by the maximum pixel value in a 3 x 3 window */
      cvipImage = maximum_filter(cvipImage,3);
      print_CVIP("\n\t\tEnter the Output File Name:  ");
      outputfile = getString_CVIP();
      view_Image(cvipImage,outputfile);
      write_Image(cvipImage,outputfile,CVIP_NO,CVIP_NO,format,1);
      free(outputfile);
      }

BUGS

     None.

AUTHOR

     Copyright (C) 1992, 1996 SIUE - by Scott E. Umbaugh and John
     A Creighton.