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histogrm.c

Go to the documentation of this file.

#include        "sadie.h"

/*-Copyright Information------------------------------------------------------*/
/* Copyright (c) 1988 by the University of Arizona Digital Image Analysis Lab */
/*----------------------------------------------------------------------------*/
/*-General Information--------------------------------------------------------*/
/*                                                                            */
/*   This low-level function computes the histograms for all image bands.     */
/*                                                                            */
/*----------------------------------------------------------------------------*/
/*-Interface Information------------------------------------------------------*/
void
HISTOGRM (IMAGE * in,           /*  I   Pointer to the image.                                 */
          short inc,            /*  I   Pixels/line and line increment.                       */
          PIXEL gmin,           /*  I   Minimum graylevel to use in histogram.                */
          PIXEL gmax,           /*  I   Maximum graylevel to use in histogram.                */
          short nlev,           /*  I   Number of bins in the histogram.                      */
          long *hist            /*  O   Pointer to the histogram array[in->nbnd*nlev].        */
/*----------------------------------------------------------------------------*/
  )
{
  register short i, j, k;
  double factor = (double) nlev / (double) (gmax - gmin + 1);

  if (TIMES)
    TIMING (T_HISTOGRM);

  /* compute histogram for each band, clip if necessary */
  for (i = 0; i < in->nbnd * nlev; i++)
    {
      hist[i] = 0L;
    }
  for (i = 0; i < in->nbnd; i++)
    {
      for (j = 0; j < in->nlin; j += inc)
        {
          for (k = 0; k < in->npix; k += inc)
            {
              if (in->data[i][j][k] <= gmin)
                {
                  hist[i * nlev + 0] += 1L;
                }
              else if (gmin < in->data[i][j][k] && in->data[i][j][k] < gmax)
                {
                  hist[i * nlev +
                       (short) ((double) (in->data[i][j][k] - gmin) *
                                factor)] += 1L;
                }
              else
                {
                  hist[i * nlev + nlev - 1] += 1L;
                }
            }
        }
    }

the_end:
  if (TIMES)
    TIMING (T_EXIT);
}

/*-Copyright Information------------------------------------------------------*/
/* Copyright (c) 1988 by the University of Arizona Digital Image Analysis Lab */
/*----------------------------------------------------------------------------*/
/*-General Information--------------------------------------------------------*/
/*                                                                            */
/*   This low-level function computes a histograms for all image bands using  */
/*   only data in the specified range.                                        */
/*                                                                            */
/*----------------------------------------------------------------------------*/
/*-Interface Information------------------------------------------------------*/
void
STRICTHISTOGRM (IMAGE * in,     /*  I   Pointer to the image.                                 */
                short inc,      /*  I   Pixels/line and line increment.                       */
                short option,   /*  I   Switch, indicating how to use input pixel range:      */
                /*      INCLUDE - Use only this input range for computing     */
                /*                statistics.                                 */
                /*      EXCLUDE - Exclude this pixel range.                   */
                PIXEL gmin,     /*  I   Minimum graylevel in range.                           */
                PIXEL gmax,     /*  I   Maximum graylevel in range.                           */
                short nlev,     /*  I   Number of bins in the histogram.                      */
                long *hist      /*  O   Pointer to the histogram array[in->nbnd*nlev].        */
/*----------------------------------------------------------------------------*/
  )
{
  register short i, j, k;
  double factor;

  if (TIMES)
    TIMING (T_HISTOGRM);

  RANGE (in);

  if (option == INCLUDE)
    {
      factor = (double) nlev / (double) (gmax - gmin + 1);
    }
  else
    {
      factor = (double) nlev / (double) (in->gmax - in->gmin + 1);
    }

  /* compute histogram for each band, clip if necessary */
  for (i = 0; i < in->nbnd * nlev; i++)
    {
      hist[i] = 0L;
    }
  for (i = 0; i < in->nbnd; i++)
    {
      for (j = 0; j < in->nlin; j += inc)
        {
          for (k = 0; k < in->npix; k += inc)
            {
              if (option == INCLUDE)
                {
                  if (in->data[i][j][k] == gmin)
                    {
                      hist[i * nlev + 0] += 1L;
                    }
                  else if (gmin < in->data[i][j][k]
                           && in->data[i][j][k] < gmax)
                    {
                      hist[i * nlev +
                           (short) ((double) (in->data[i][j][k] - gmin) *
                                    factor)] += 1L;
                    }
                  else if (in->data[i][j][k] == gmax)
                    {
                      hist[i * nlev + nlev - 1] += 1L;
                    }
                }
              else
                {
                  if (in->data[i][j][k] < gmin || in->data[i][j][k] > gmax)
                    {
                      if (in->data[i][j][k] == in->gmin)
                        {
                          hist[i * nlev + 0] += 1L;
                        }
                      else if (in->data[i][j][k] == in->gmax)
                        {
                          hist[i * nlev + nlev - 1] += 1L;
                        }
                      else
                        {
                          hist[i * nlev +
                               (short) ((double)
                                        (in->data[i][j][k] -
                                         in->gmin) * factor)] += 1L;
                        }
                    }
                }
            }
        }
    }

the_end:
  if (TIMES)
    TIMING (T_EXIT);
}

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