path: root/toolbin/tests/fuzzy.c

/* Copyright (C) 2001-2021 Artifex Software, Inc.
   All Rights Reserved.

   This software is provided AS-IS with no warranty, either express or
   implied.

   This software is distributed under license and may not be copied,
   modified or distributed except as expressly authorized under the terms
   of the license contained in the file LICENSE in this distribution.

   Refer to licensing information at http://www.artifex.com or contact
   Artifex Software, Inc.,  1305 Grant Avenue - Suite 200, Novato,
   CA 94945, U.S.A., +1(415)492-9861, for further information.
*/

/**
 * Fuzzy comparison utility.
 **/

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <memory.h>
#include <sys/stat.h>
#include <math.h>

typedef unsigned char uchar;
typedef int bool;
#define FALSE 0
#define TRUE 1

#define BMP_FILE_HEADER_SIZE 14
#define BMP_INFO_HEADER_SIZE 40
#define BMP_HEADER_SIZE ((BMP_FILE_HEADER_SIZE) + \
                                (BMP_INFO_HEADER_SIZE))

#define MIN(x,y) ((x)>(y)?(y):(x))
#define MAX(x,y) ((x)>(y)?(x):(y))

typedef struct _Image Image;

struct _Image {
  int (*close) (Image *self);
  int (*get_scan_line) (Image *self, uchar *buf);
  int (*seek) (Image *self, int y);
  int (*write) (Image *self, uchar *buf, int size);
  int (*feof_) (Image *self);
  int width;
  int height;
  int maxval;
  int n_chan;
  int raster;
  int bpp; /* bits per pixel */
};

typedef struct _FuzzyParams FuzzyParams;

struct _FuzzyParams {
  int tolerance;    /* in pixel counts */
  int window_size;
  bool report_coordinates;
};

typedef struct _FuzzyReport FuzzyReport;

struct _FuzzyReport {
  int n_diff;
  int n_outof_tolerance;
  int n_outof_window;
  double max_color_error;
  double avg_color_error;
};

int packBits(unsigned char *buffer, unsigned char *outBuffer, int length, int stride) {
    unsigned char *nextToWrite;
    int repCount, diffCount, totalBytes, i;
    unsigned char pixData;

    pixData=(unsigned char) 0;
    nextToWrite = buffer;
    repCount = 1;
    diffCount = 0;
    totalBytes = 0;
    while(--length) {
        pixData = *buffer;
        buffer+=stride;
        if (pixData == *buffer) {
            repCount++;
        } else {
            if (repCount > 2 || (repCount>1 && diffCount==0)) {
                while (diffCount)
                    if (diffCount > 128) {
                        totalBytes+=129;
                        *(outBuffer++)=(unsigned char) 0x7f;
                        for (i=0; i<128; i++) {
                            *(outBuffer++)=*nextToWrite;
                            nextToWrite+=stride;
                        }
                        diffCount-=128;
                    } else {
                        totalBytes+=diffCount+1;
                        *(outBuffer++)=(unsigned char) (diffCount-1);
                        for (i=0; i<diffCount; i++) {
                            *(outBuffer++)=*nextToWrite;
                            nextToWrite+=stride;
                        }
                        diffCount=0;
                    }
                nextToWrite+=repCount*stride;
                while (repCount) {
                    totalBytes+=2;
                    if (repCount > 128)
                        if (repCount==129) {
                            *(outBuffer++)=(unsigned char) 0x81;
                            *(outBuffer++)=pixData;
                            repCount=0;
                            diffCount++;
                            nextToWrite-=stride;
                        } else {
                            *(outBuffer++)=(unsigned char) 0x81;
                            *(outBuffer++)=pixData;
                            repCount-=128;
                        }
                    else {
                        *(outBuffer++)=(unsigned char) (-(repCount-1));
                        *(outBuffer++)=pixData;
                        repCount=0;
                    }
                }
                repCount=1;
            } else {
                diffCount+=repCount;
                repCount=1;
            }
        }
    }
    if (repCount < 3 && (repCount<2 || diffCount>0)) {
        diffCount+=repCount;
        repCount=0;
    }
    while (diffCount)
        if (diffCount > 128) {
            totalBytes+=129;
            *(outBuffer++)=(unsigned char) 0x7f;
            for (i=0; i<128; i++) {
                *(outBuffer++)=*nextToWrite;
                nextToWrite+=stride;
            }
            diffCount-=128;
        } else {
            totalBytes+=diffCount+1;
            *(outBuffer++)=(unsigned char) (diffCount-1);
            for (i=0; i<diffCount; i++) {
                *(outBuffer++)=*nextToWrite;
                nextToWrite+=stride;
            }
            diffCount=0;
        }
    while (repCount) {
        totalBytes+=2;
        if (repCount > 128) {
            if (repCount==129) {
                *(outBuffer++)=(unsigned char) 0x82;
                *(outBuffer++)=pixData;
                repCount-=127;
            } else {
                *(outBuffer++)=(unsigned char) 0x81;
                *(outBuffer++)=pixData;
                repCount-=128;
            }
        } else {
            *(outBuffer++)=(unsigned char) (-(repCount-1));
            *(outBuffer++)=pixData;
            repCount=0;
        }
    }
    return totalBytes;
}

static off_t
file_length(int file)
{
  struct stat st;

  fstat(file, &st);
  return st.st_size;
}

int
image_get_rgb_scan_line (Image *image, uchar *buf)
{
  uchar *image_buf;
  int width = image->width;
  int code;
  int x;

  if (image->n_chan == 3 && image->bpp == 8)
    return image->get_scan_line (image, buf);

  image_buf = malloc (image->raster);
  code = image->get_scan_line (image, image_buf);
  if (code < 0)
    {
      /* skip */
    }
  else if (image->n_chan == 1 && image->bpp == 8)
    {
      for (x = 0; x < width; x++)
        {
          uchar g = image_buf[x];
          buf[x * 3] = g;
          buf[x * 3 + 1] = g;
          buf[x * 3 + 2] = g;
        }
    }
  else if (image->n_chan == 1 && image->bpp == 1)
    {
      for (x = 0; x < width; x++)
        {
          uchar g = -!(image_buf[x >> 3] & (128 >> (x & 7)));
          buf[x * 3] = g;
          buf[x * 3 + 1] = g;
          buf[x * 3 + 2] = g;
        }
    }
  else
    code = -1;
  free (image_buf);
  return code;
}
int
image_get_rgb_scan_line_with_error (Image *image, uchar *buf, int image_index, int row_index, int *rcode)
{
    int code = image_get_rgb_scan_line (image, buf);

    if (code == 1) {
        *rcode = 1;
        printf("*** I/O error in file %d at y = %d\n", image_index, row_index);
    }
    return code;
}

typedef struct _ImagePnm ImagePnm;

struct _ImagePnm {
  Image super;
  FILE *f;
  long file_length;
};

int
image_close (Image *image)
{
  return image->close (image);
}

static int
no_seek(Image *self, int y)
{
  return 0;
}

static int
write(Image *self, uchar *out_buf, int out_buffer_size) {
  ImagePnm *pnm = (ImagePnm *)self;
  return(fwrite(out_buf, 1, out_buffer_size, pnm->f) != out_buffer_size);
}

static int
image_pnm_close (Image *self)
{
  ImagePnm *pnm = (ImagePnm *)self;
  int code;

  code = fclose (pnm->f);
  free (self);
  return code;
}

static ImagePnm *
create_pnm_image_struct(Image *templ, const char *path)
{
  FILE *f = fopen(path,"w+b");
  ImagePnm *pnm = (ImagePnm *)malloc(sizeof(ImagePnm));

  if (pnm == NULL) {
    printf ("Insufficient RAM.\n");
    return NULL;
  }
  if (f == NULL) {
    printf ("Can't create the file %s\n", path);
    return NULL;
  }
  pnm->f = f;
  pnm->super = *templ;
  pnm->super.seek = no_seek;
  pnm->super.write = write;
  pnm->super.bpp = 8;    /* Now support this value only. */
  pnm->super.n_chan = 3; /* Now support this value only. */
  return pnm;
}

static ImagePnm *
create_pnm_image(Image *templ, const char *path)
{
  ImagePnm *pnm = create_pnm_image_struct(templ, path);

  if (pnm == NULL)
    return NULL;

  fprintf(pnm->f,"P6\n");
  fprintf(pnm->f,"# Generated by Ghostscript's fuzzy.c\n");
  fprintf(pnm->f,"%d %d\n", templ->width, pnm->super.height);
  fprintf(pnm->f,"255\n");
  return pnm;
}

static int
image_pnm_feof (Image *self)
{
  ImagePnm *pnm = (ImagePnm *)self;

  return feof (pnm->f) || ftell(pnm->f) == pnm->file_length;
}

static void
write_int16(short v, FILE *f)
{
  uchar val[2];
  val[0] = (uchar)(v & 0xff);
  val[1] = (uchar)((v >> 8) & 0xff);
  fwrite(val, 2, 1, f);
}

static void
write_int32(int v, FILE *f)
{
  uchar val[4];
  val[0] = (uchar)(v & 0xff);
  val[1] = (uchar)((v >> 8) & 0xff);
  val[2] = (uchar)((v >> 16) & 0xff);
  val[3] = (uchar)((v >> 24) & 0xff);
  fwrite(val, 4, 1, f);
}

static int
seek_bmp_image(Image *self, int y)
{
  ImagePnm *pnm = (ImagePnm *)self;
  long pos = BMP_HEADER_SIZE + self->raster * (self->height - y - 1);
  int r = fseek(pnm->f, pos, SEEK_SET);

  return r;
}

static ImagePnm *
create_bmp_image(Image *templ, const char *path)
{
  int raster = (templ->width * 3 + 3) & ~3;
  int nImageSize = raster * templ->height;
  int nFileSize = BMP_HEADER_SIZE + nImageSize;
  ImagePnm *pnm = create_pnm_image_struct(templ, path);

  if (pnm == NULL)
    return NULL;
  pnm->super.seek = seek_bmp_image;
  pnm->super.write = write;
  pnm->super.raster = raster;

  /* BMP file header */
  fputc('B', pnm->f);
  fputc('M', pnm->f);
  write_int32(nFileSize, pnm->f);
  write_int16(0, pnm->f); /* reserved fields are zero */
  write_int16(0, pnm->f);
  write_int32(BMP_HEADER_SIZE, pnm->f);

  /* BMP info header */
  write_int32(BMP_INFO_HEADER_SIZE, pnm->f);
  write_int32(templ->width, pnm->f);
  write_int32(pnm->super.height, pnm->f);
  write_int16(1, pnm->f);	/* planes */
  write_int16(24, pnm->f);	/* bit count */
  write_int32(1, pnm->f);	/* compression */
  write_int32(0, pnm->f);	/* size image */
  write_int32(3780, pnm->f);	/* resolution in pixels per meter */
  write_int32(3780, pnm->f);	/* use a default 96 dpi */
  write_int32(0, pnm->f);	/* ClrUsed */
  write_int32(0, pnm->f);	/* ClrImportant */

  /* fseek beyond file end doesn't work with MSVC so we pad
     out to the size of the image data at file open time.    */
  {
    uchar *linebuf = malloc(raster);
    if (linebuf == NULL) {
        printf ("Couldn't allocate dummy bmp line buffer; diff image may be corrupt.\n");
    } else {
        int k;

        memset(linebuf, 0, raster);

        for (k = 0; k < pnm->super.height; k++)
            fwrite(linebuf, 1, raster, pnm->f);

        free(linebuf);
    }
  }

  return pnm;
}

static uchar rawCompressionBuffer[65000];

static int
compressedWrite(Image *self, uchar *out_buf, int out_buffer_size) {
  ImagePnm *pnm = (ImagePnm *)self;
  int p;
  int t;
  for (p=0;  p<3;  p++) {
    t=packBits(out_buf+p,rawCompressionBuffer,out_buffer_size/3,3);
    if (fwrite(rawCompressionBuffer,t,1,pnm->f)!=1) {
      return(1);
    }
  }
  return(0);
}

static ImagePnm *
create_raw_image_struct(Image *templ, const char *path)
{
  FILE *f = fopen(path,"w+b");
  ImagePnm *pnm = (ImagePnm *)malloc(sizeof(ImagePnm));

  if (pnm == NULL) {
    printf ("Insufficient RAM.\n");
    return NULL;
  }
  if (f == NULL) {
    printf ("Can't create the file %s\n", path);
    return NULL;
  }
  pnm->f = f;
  pnm->super = *templ;
  pnm->super.seek = no_seek;
  pnm->super.write = compressedWrite;
  pnm->super.bpp = 8;    /* Now support this value only. */
  pnm->super.n_chan = 3; /* Now support this value only. */
  return pnm;
}

int writeInt(int i, FILE *stream) {
    putc(i>>8, stream);
    return (putc(i&0xff, stream));
}


static ImagePnm *
create_raw_image(Image *templ, const char *path)
{
  ImagePnm *pnm = create_raw_image_struct(templ, path);

  if (pnm == NULL)
    return NULL;

  fwrite((char *) "mhwanh", 1, 6, pnm->f);
  writeInt(5,pnm->f);  /* version */
  writeInt(templ->width,pnm->f);
  writeInt(templ->height,pnm->f);
  writeInt(0,pnm->f); /* bpp */
  writeInt(0,pnm->f); /* dpiX */
  writeInt(0,pnm->f); /* dpiY */
  writeInt(0,pnm->f); /* gamma */
  writeInt(1,pnm->f); /* compression */
  writeInt(0,pnm->f); /* alpha */
  writeInt(0,pnm->f);
  writeInt(0,pnm->f);
  writeInt(0,pnm->f);
  writeInt(0,pnm->f);
  return pnm;
}


static int
image_pnm_get_scan_line (Image *self, uchar *buf)
{
  ImagePnm *pnm = (ImagePnm *)self;
  int n_bytes = self->raster;
  int code;
  int bppval = (1 << self->bpp) -1;
  int maxval = self->maxval;

  code = fread (buf, 1, n_bytes, pnm->f);
  if (maxval < bppval) {
      int i;
      for(i = 0; i<n_bytes; i++)
        buf[i] = buf[i] * bppval / maxval;
  }
  return (code < n_bytes) ? -1 : 0;
}

ImagePnm *
alloc_pnm_image (const char *fn)
{
  ImagePnm *image;

  FILE *f = fopen (fn, "rb");

  if (f == NULL) {
      printf("Can't open file %s\n", fn);
      return NULL;
  }
  image = (ImagePnm *)malloc (sizeof(ImagePnm));
  image->f = f;
  image->file_length = file_length(fileno(f));
  return image;
}

int
open_pnm_image (ImagePnm *image)
{
  int width, height;
  int maxval = 0;
  int n_chan, bpp;
  char linebuf[256];

  if (fgets (linebuf, sizeof(linebuf), image->f) == NULL ||
      linebuf[0] != 'P' || linebuf[1] < '4' || linebuf[1] > '6')
    return 1;
  switch (linebuf[1])
    {
    case '4':
      n_chan = 1;
      bpp = 1;
      maxval = 1;
      break;
    case '5':
      n_chan = 1;
      bpp = 8;
      break;
    case '6':
      n_chan = 3;
      bpp = 8;
      break;
    default:
      return 1;
    }
  do
    {
      if (fgets (linebuf, sizeof(linebuf), image->f) == NULL)
          return 1;
    }
  while (linebuf[0] == '#');
  if (sscanf (linebuf, "%d %d", &width, &height) != 2)
      return 1;
  while (!maxval)
    {
      if (fgets (linebuf, sizeof(linebuf), image->f) == NULL)
          return 1;
      if (linebuf[0] == '#')
          continue;
      if (sscanf(linebuf, "%d", &maxval) != 1 || maxval <= 0 || maxval > 255)
          return 1;
    }
  image->super.width = width;
  image->super.height = height;
  image->super.maxval = maxval;
  image->super.raster = n_chan * ((width * bpp + 7) >> 3);
  image->super.n_chan = n_chan;
  image->super.bpp = bpp;
  return 0;
}

Image *
alloc_image_file (const char *fn)
{
  /* This is the place to add a dispatcher for other image types. */
    ImagePnm *image = alloc_pnm_image (fn);

  if (image == NULL)
    return NULL;
  image->super.close = image_pnm_close;
  image->super.get_scan_line = image_pnm_get_scan_line;
  image->super.seek = no_seek;
  image->super.write = write;
  image->super.feof_ = image_pnm_feof;
  return &image->super;
}

static int
open_image (Image *self)
{
  /* This is the place to add a dispatcher for other image types. */
  ImagePnm *pnm = (ImagePnm *)self;

  return open_pnm_image (pnm);
}

static uchar **
alloc_window (int row_bytes, int window_size)
{
  uchar **buf = (uchar **)malloc (window_size * sizeof(uchar *));
  int i;

  for (i = 0; i < window_size; i++)
    buf[i] = malloc (row_bytes);
  return buf;
}

static void
free_window (uchar **buf, int window_size)
{
  int i;

  for (i = 0; i < window_size; i++)
    free (buf[i]);
  free (buf);
}

static void
roll_window (uchar **buf, int window_size)
{
  int i;
  uchar *tmp1, *tmp2;

  tmp1 = buf[window_size - 1];
  for (i = 0; i < window_size; i++)
    {
      tmp2 = buf[i];
      buf[i] = tmp1;
      tmp1 = tmp2;
    }
}

static bool
check_window (uchar **buf1, uchar **buf2,
              const FuzzyParams *fparams,
              int x, int y, int width, int height)
{
  int tolerance = fparams->tolerance;
  int window_size = fparams->window_size;
  int i, j;
  const int half_win = window_size >> 1;
  const uchar *rowmid1 = buf1[half_win];
  const uchar *rowmid2 = buf2[half_win];
  uchar r1 = rowmid1[x * 3], g1 = rowmid1[x * 3 + 1], b1 = rowmid1[x * 3 + 2];
  uchar r2 = rowmid2[x * 3], g2 = rowmid2[x * 3 + 1], b2 = rowmid2[x * 3 + 2];
  bool match1 = FALSE, match2 = FALSE;

  for (j = -half_win; j <= half_win; j++)
    {
      const uchar *row1 = buf1[j + half_win];
      const uchar *row2 = buf2[j + half_win];
      for (i = -half_win; i <= half_win; i++)
        if ((i != 0 || j != 0) &&
            x + i >= 0 && x + i < width &&
            y + j >= 0 && y + j < height)
          {
            if (abs (r1 - row2[(x + i) * 3]) <= tolerance &&
                abs (g1 - row2[(x + i) * 3 + 1]) <= tolerance &&
                abs (b1 - row2[(x + i) * 3 + 2]) <= tolerance)
              match1 = TRUE;
            if (abs (r2 - row1[(x + i) * 3]) <= tolerance &&
                abs (g2 - row1[(x + i) * 3 + 1]) <= tolerance &&
                abs (b2 - row1[(x + i) * 3 + 2]) <= tolerance)
              match2 = TRUE;
          }
    }
  return !(match1 && match2);
}



static int
fuzzy_diff_images (Image *image1, Image *image2, const FuzzyParams *fparams,
                   FuzzyReport *freport, ImagePnm *image_out)
{
  int width = MIN(image1->width, image2->width);
  int height = MIN(image1->height, image2->height);
  int max_height = MAX(image1->height, image2->height);
  int tolerance = fparams->tolerance;
  int window_size = fparams->window_size;
  int row_bytes = width * 3;
  unsigned int out_buffer_size = (image_out ? row_bytes : 0);
  int half_win = window_size >> 1;
  uchar **buf1 = alloc_window (row_bytes*2, window_size);
  uchar **buf2 = alloc_window (row_bytes*2, window_size);
  uchar *out_buf = NULL;
  int x0 = -2, y0 = -2, mc = 0, mmax = 10;
  int y;
  int rcode = 0;
  double diff[3];
  double color_diff;

  if (image_out != NULL)
    {
      out_buf = malloc(out_buffer_size*2);
      if (out_buf == NULL)
        printf ("Can't allocate output buffer.\n");
    }

  /* Read rows ahead for half window : */
  for (y = 0; y < MIN(half_win, height); y++)
    {
       if (image_get_rgb_scan_line_with_error (image1, buf1[half_win - y], 1, y, &rcode))
            goto ex;
       if (image_get_rgb_scan_line_with_error (image2, buf2[half_win - y], 2, y, &rcode))
            goto ex;
    }
  /* Initialie remaining scanlines if height < half_win */
  for (; y < half_win; y++) {
    memcpy(buf1[half_win - y], buf1[half_win], width * 3);
    memcpy(buf2[half_win - y], buf2[half_win], width * 3);
  }

  /* Initialie the rest of the buffer that would be uninitialised */
  /* before half_win lines is read, because check_window() always */
  /* peeks into the whole window */
  for (y = 0; y < half_win; y++) {
    memcpy(buf1[half_win + y + 1], buf1[half_win], width * 3);
    memcpy(buf2[half_win + y + 1], buf2[half_win], width * 3);
  }

  /* Do compare : */
  for (y = 0; y < height; y++)
    {
      int x;
      uchar *row1 = buf1[0];
      uchar *row2 = buf2[0];
      uchar *rowmid1 = buf1[half_win];
      uchar *rowmid2 = buf2[half_win];

      if (y < height - half_win)
        {
            if (image_get_rgb_scan_line_with_error (image1, row1, 1, y + half_win, &rcode))
                goto ex;
            if (image_get_rgb_scan_line_with_error (image2, row2, 2, y + half_win, &rcode))
                goto ex;
        }
      if (out_buf)
        memset(out_buf, 0, out_buffer_size*2);

      if (memcmp(rowmid1, rowmid2, width * 3))
        {
          for (x = 0; x < width; x++)
            {
              if (rowmid1[x * 3] != rowmid2[x * 3] ||
                  rowmid1[x * 3 + 1] != rowmid2[x * 3 + 1] ||
                  rowmid1[x * 3 + 2] != rowmid2[x * 3 + 2])
                {
                  freport->n_diff++;
                  /* If max error is the largest it can be in a 3 band
                     unsigned char image, then stop collecting this
                     information since we are likely dealing with a half
                     tone image and the max color error is not of interest */
                  if ( freport->max_color_error < 440) {
                      diff[0] = rowmid1[x * 3] - rowmid2[x * 3];
                      diff[1] = rowmid1[x * 3 + 1] - rowmid2[x * 3 + 1];
                      diff[2] = rowmid1[x * 3 + 2] - rowmid2[x * 3 + 2];
                      color_diff = sqrt(diff[0]*diff[0] + diff[1]*diff[1] + diff[2]*diff[2]);
                      if (color_diff > freport->max_color_error) {
                        freport->max_color_error = color_diff;
                      }
                      if( freport->n_diff == 1) {
                        freport->avg_color_error = color_diff;
                      } else {
                        freport->avg_color_error =
                            ( freport->avg_color_error*(freport->n_diff-1) +
                              color_diff) / freport->n_diff;
                      }
                  }
                  if (abs (rowmid1[x * 3] - rowmid2[x * 3]) > tolerance ||
                      abs (rowmid1[x * 3 + 1] - rowmid2[x * 3 + 1]) > tolerance ||
                      abs (rowmid1[x * 3 + 2] - rowmid2[x * 3 + 2]) > tolerance)
                    {
                      freport->n_outof_tolerance++;
                      if (check_window (buf1, buf2, fparams, x, y, width, height)) {
                        freport->n_outof_window++;
                        if (out_buf && x < image1->width) {
                          out_buf[x * 3 + 0] = abs(rowmid1[x * 3 + 0]- rowmid2[x * 3 + 0]);
                          out_buf[x * 3 + 1] = abs(rowmid1[x * 3 + 1]- rowmid2[x * 3 + 1]);
                          out_buf[x * 3 + 2] = abs(rowmid1[x * 3 + 2]- rowmid2[x * 3 + 2]);
                        }
                        if (fparams->report_coordinates &&
                            ((abs(x - x0) > 1 && y == y0) || y - y0 > 1))
                          {
                            /* fixme : a contiguity test wanted. */
                            x0 = x; y0 = y;
                            mc++;
                            if (mc < mmax) {
                                printf("diff: x=%d y=%d c1=%02X%02X%02X c2=%02X%02X%02X\n", x, y,
                                        rowmid1[x * 3], rowmid1[x * 3 + 1], rowmid1[x * 3 + 2],
                                        rowmid2[x * 3], rowmid2[x * 3 + 1], rowmid2[x * 3 + 2]);
                            } else if (mc == mmax)
                                printf("Won't report more differences.\n");
                        }
                      }
                    }
                }
            }
        }

      roll_window (buf1, window_size);
      roll_window (buf2, window_size);
      if (out_buf) {
        if (image_out->super.seek(&image_out->super, y))
          {
            printf ("I/O Error seeking to the output image position.\n");
            free(out_buf);
            out_buf = NULL;
          }
        else if (image_out->super.write(&image_out->super, out_buf, out_buffer_size))

          {
            printf ("I/O Error writing the output image.\n");
            free(out_buf);
            out_buf = NULL;
          }
      }
    }
  y += half_win;
  for (; y < max_height; y++) {
      if (y < image1->height) {
            if (image_get_rgb_scan_line_with_error(image1, buf1[0], 1, y, &rcode))
                goto ex;
      }
      if (y < image2->height) {
            if (image_get_rgb_scan_line_with_error(image2, buf2[0], 2, y, &rcode))
                goto ex;
      }
  }
ex:
  free_window (buf1, window_size);
  free_window (buf2, window_size);
  if (out_buf)
    free(out_buf);
  return rcode;
}

static const char *
get_arg (int argc, char **argv, int *pi, const char *arg)
{
  if (arg[0] != 0)
    return arg;
  else
    {
      (*pi)++;
      if (*pi == argc)
        return NULL;
      else
        return argv[*pi];
    }
}

int
usage (void)
{
  printf ("Usage: fuzzy [-w window_size] [-t tolerance] [-c] a.ppm b.ppm [diff.ppm | diff.bmp]\n");
  return 1;
}

int
main (int argc, char **argv)
{
  Image *image1,  *image2;
  ImagePnm *image_out = NULL;
  FuzzyParams fparams;
  FuzzyReport freport;
  const char *fn[3] = {0, 0, 0};
  int fn_idx = 0;
  int i, page = 1, rcode = 0;
  char *out_fn = NULL;

  fparams.tolerance = 2;
  fparams.window_size = 3;
  fparams.report_coordinates = FALSE;

  for (i = 1; i < argc; i++)
    {
      const char *arg = argv[i];

      if (arg[0] == '-')
        {
          switch (arg[1])
            {
            case 'w':
              fparams.window_size = atoi (get_arg (argc, argv, &i, arg + 2));
              if ((fparams.window_size & 1) == 0)
                {
                  printf ("window size must be odd\n");
                  return 1;
                }
              break;
            case 't':
              fparams.tolerance = atoi (get_arg (argc, argv, &i, arg + 2));
              break;
            case 'c':
              fparams.report_coordinates = TRUE;
              break;
            default:
              return usage ();
            }
        }
      else if (fn_idx < sizeof(fn)/sizeof(fn[0]))
        fn[fn_idx++] = argv[i];
      else
        return usage ();
    }

  if (fn_idx < 2)
    return usage ();

  image1 = alloc_image_file (fn[0]);
  if (image1 == NULL)
      return 1;

  image2 = alloc_image_file (fn[1]);
  if (image2 == NULL)
    {
      image_close (image1);
      return 1;
    }

  if (fn[2]) {
      out_fn = malloc(strlen(fn[2]) + 5);
      if (out_fn == NULL) {
          printf("Can't alloc the output file name.\n");
          return 1;
      }
  }

  while (!image1->feof_(image1) || !image2->feof_(image2))
  {
    if (image1->feof_(image1))
    {
      printf ("Extra data (maybe pages) in the image file 2.\n");
      return 1;
    }
    if (image2->feof_(image2))
    {
      printf ("Extra data (maybe pages) in the image file 1.\n");
      return 1;
    }
    if (open_image(image1))
    {
      printf ("Error parsing the page %d header in file %s\n", page, fn[0]);
      return 1;
    }

    if (open_image(image2))
    {
      printf ("Error parsing the page %d header in file %s\n", page, fn[1]);
      return 1;
    }
    if (image1->width != image2->width) {
        printf("Different image width for page %d (%d vs %d)\n", page,image1->width,image2->width);
        rcode = MAX(rcode, 1);
        if (image1->width*2<image2->width)
          return(rcode);
    }
    if (image1->height != image2->height) {
        printf("Different image height for page %d (%d vs %d)\n", page,image1->height,image2->height);
        rcode = MAX(rcode, 1);
    }
    if (out_fn != NULL) {
      int l = strlen(fn[2]);

      strcpy(out_fn, fn[2]);
      for (i = l; i >= 0; i--) {
          if (out_fn[i] == '\\' || out_fn[i] == '/' || out_fn[i] == '.')
              break;
      }
      if (out_fn[i] == '.') {
          char c;

          memmove(out_fn + i + 4, out_fn + i, l + 1 - i);
          c = out_fn[i + 4];
          sprintf(out_fn + i, "-%03d", page);
          out_fn[i + 4] = c;
      } else
          sprintf(out_fn + l, "-%03d", page);
      if (!strcmp(fn[2]+ strlen(fn[2]) - 4, ".bmp"))
        image_out = create_bmp_image(image1, out_fn);
      else if (!strcmp(fn[2]+ strlen(fn[2]) - 4, ".raw"))
        image_out = create_raw_image(image1, out_fn);
      else
         image_out = create_pnm_image(image1, out_fn);
    } else
      image_out = NULL;

    freport.n_diff = 0;
    freport.n_outof_tolerance = 0;
    freport.n_outof_window = 0;
    freport.avg_color_error = 0;
    freport.max_color_error = 0;
    if (fuzzy_diff_images (image1, image2, &fparams, &freport, image_out))
        return 1;
    if (image_out)
      image_pnm_close (&image_out->super);
    image_out = NULL;
    if (freport.n_diff > 0)
    {
      printf ("%s: page %d: %d diff., %d out of tol., %d out of win., %3.2lf avg diff, %3.2lf max diff\n",
              fn[0], page, freport.n_diff, freport.n_outof_tolerance,
              freport.n_outof_window,freport.avg_color_error,
              freport.max_color_error);
      rcode = MAX(rcode, 1);
    }
    if (freport.n_outof_window > 0)
      rcode = MAX(rcode, 2);
    page++;
  }
  image_close (image1);
  image_close (image2);
  return rcode;
}