imgscale.cpp File Reference

#include "mfcpch.h"
#include <stdio.h>
#include <stdlib.h>
#include "errcode.h"

Go to the source code of this file.

Macros
#define	f(xc, yc)   ((xc - factor*yc)*(xc - factor*yc))
#define	g(oldyc, yc, oldxc, xc)   (factor*factor*(oldyc - yc)*(oldyc - yc)/(abs(oldxc - xc) + 1))

Functions
void	dyn_exit (const char s[])
void	dyn_prog (int n, int *x, int *y, int ymax, int *oldx, int *oldy, int oldn, float factor)

Macro Definition Documentation

#define f	(		xc,
			yc
	)		((xc - factor*yc)*(xc - factor*yc))

Definition at line 39 of file imgscale.cpp.

#define g	(		oldyc,
			yc,
			oldxc,
			xc
	)		(factor*factor*(oldyc - yc)*(oldyc - yc)/(abs(oldxc - xc) + 1))

Definition at line 41 of file imgscale.cpp.

Function Documentation

void dyn_exit

(

const char

s[]

)

Definition at line 44 of file imgscale.cpp.

                          {
  fprintf (stderr, "%s", s);
  err_exit(); 
}

void dyn_prog	(	int	n,
		int *	x,
		int *	y,
		int	ymax,
		int *	oldx,
		int *	oldy,
		int	oldn,
		float	factor
	)

Definition at line 50 of file imgscale.cpp.

                            {
  int i, z, j, matchflag;
  int **ymin;
  float **F, fz;

  /* F[i][z] gives minimum over y <= z */

  F = (float **) calloc (n, sizeof (float *));
  ymin = (int **) calloc (n, sizeof (int *));
  if ((F == NULL) || (ymin == NULL))
    dyn_exit ("Error in calloc\n");

  for (i = 0; i < n; i++) {
    F[i] = (float *) calloc (ymax - n + i + 1, sizeof (float));
    ymin[i] = (int *) calloc (ymax - n + i + 1, sizeof (int));
    if ((F[i] == NULL) || (ymin[i] == NULL))
      dyn_exit ("Error in calloc\n");
  }

  F[0][0] = f (x[0], 0);
  /* find nearest transition of same sign (white to black) */
  j = 0;
  while ((j < oldn) && (oldx[j] < x[0]))
    j += 2;
  if (j >= oldn)
    j -= 2;
  else if ((j - 2 >= 0) && ((x[0] - oldx[j - 2]) < (oldx[j] - x[0])))
    j -= 2;
  if (abs (oldx[j] - x[0]) < factor) {
    matchflag = 1;
    F[0][0] += g (oldy[j], 0, oldx[j], x[0]);
  }
  else
    matchflag = 0;
  ymin[0][0] = 0;

  for (z = 1; z < ymax - n + 1; z++) {
    fz = f (x[0], z);
    /* add penalty for deviating from previous row if necessary */

    if (matchflag)
      fz += g (oldy[j], z, oldx[j], x[0]);
    if (fz < F[0][z - 1]) {
      F[0][z] = fz;
      ymin[0][z] = z;
    }
    else {
      F[0][z] = F[0][z - 1];
      ymin[0][z] = ymin[0][z - 1];
    }
  }

  for (i = 1; i < n; i++) {
    F[i][i] = f (x[i], i) + F[i - 1][i - 1];
    /* add penalty for deviating from previous row if necessary */
    if (j > 0)
      j--;
    else
      j++;
    while ((j < oldn) && (oldx[j] < x[i]))
      j += 2;
    if (j >= oldn)
      j -= 2;
    else if ((j - 2 >= 0) && ((x[i] - oldx[j - 2]) < (oldx[j] - x[i])))
      j -= 2;
    if (abs (oldx[j] - x[i]) < factor) {
      matchflag = 1;
      F[i][i] += g (oldy[j], i, oldx[j], x[i]);
    }
    else
      matchflag = 0;
    ymin[i][i] = i;
    for (z = i + 1; z < ymax - n + i + 1; z++) {
      fz = f (x[i], z) + F[i - 1][z - 1];
      /* add penalty for deviating from previous row if necessary */
      if (matchflag)
        fz += g (oldy[j], z, oldx[j], x[i]);
      if (fz < F[i][z - 1]) {
        F[i][z] = fz;
        ymin[i][z] = z;
      }
      else {
        F[i][z] = F[i][z - 1];
        ymin[i][z] = ymin[i][z - 1];
      }
    }
  }

  y[n - 1] = ymin[n - 1][ymax - 1];
  for (i = n - 2; i >= 0; i--)
    y[i] = ymin[i][y[i + 1] - 1];

  for (i = 0; i < n; i++) {
    free (F[i]);
    free (ymin[i]);
  }
  free(F); 
  free(ymin); 

  return;
}