## NAME

         Ideal_Band_Reject - perform ideal band reject filtering

## SYNOPSIS

          #include <math.h>
          #include <stdio.h>
          #include <stdlib.h>
          #include "CVIPdef.h"
          #include "CVIPimage.h"

         Image *Ideal_Band_Reject(Image *in_Image,int  block_size,int
         dc,int inner,int  outer)

          <in_Image> - pointer to an Image structure
          <block_size> - desired block size
          <dc> - drop(0) or retain(1) dc component
          <inner> - inner cutoff frequency
          <outer> - outer cutoff frequency

## PATH

         $CVIPHOME/XFORMFILTER/filter.c

## DESCRIPTION

         Ideal_Band_Reject() performs two-dimensional  ideal  bandre-
         ject filtering in transform domain on input image.  All fre-
         quency components that are in the band enclosed by the  cir-
         cle (or 1/4 circle if dc component is on the upper left-hand
         corner of its transform plane) with  radius  inner  and  the
         circle  with  radius outer will be filtered. All frequencies
         outside the circular band (or 1/4 circular  band)  are  left
         completely intact.  If dc equals 1, the dc component will be
         retained, if dc equals 0, it will be dropped.

## TYPES AND CONSTANTS

         None

## RETURN VALUES

         A filtered image

## HISTORY

         History information recorded: None

## EXAMPLE

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

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

          (void) 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 performs the fft_transform on the
          input image with the block size equal to 256 */
          cvipImage=(Image *)fft_transform(cvipImage,256);
          /* the following call performs the ideal band reject
          filtering  on the transformed image with the lower cut off
          equal to 0 and the higher cut off equal to 64 */
          cvipImage = (Image *)Ideal_Band_Reject(cvipImage,256,
          1,0,64);
          /* the following call performs the inverse fft_transform in
          the filtered image with the block size equal to 256 */
          cvipImage = (Image *)ifft_transform(cvipImage,256);
          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);
          }

## SEE ALSO

         libxformfilter

## AUTHOR

         Copyright (C) 1996 SIUE - by Scott E. Umbaugh and Simon Low.