filter/image-zoom.c

   1 /*
   2  * "$Id: image-zoom.c 6649 2007-07-11 21:46:42Z mike $"
   3  *
   4  *   cupsImage zoom routines for the Common UNIX Printing System (CUPS).
   5  *
   6  *   Copyright 2007 by Apple Inc.
   7  *   Copyright 1993-2006 by Easy Software Products.
   8  *
   9  *   These coded instructions, statements, and computer programs are the
  10  *   property of Apple Inc. and are protected by Federal copyright
  11  *   law.  Distribution and use rights are outlined in the file "LICENSE.txt"
  12  *   which should have been included with this file.  If this file is
  13  *   file is missing or damaged, see the license at "http://www.cups.org/".
  14  *
  15  *   This file is subject to the Apple OS-Developed Software exception.
  16  *
  17  * Contents:
  18  *
  19  *   _cupsImageZoomDelete() - Free a zoom record...
  20  *   _cupsImageZoomFill()   - Fill a zoom record...
  21  *   _cupsImageZoomNew()    - Allocate a pixel zoom record...
  22  *   zoom_bilinear()        - Fill a zoom record with image data utilizing
  23  *                            bilinear interpolation.
  24  *   zoom_nearest()         - Fill a zoom record quickly using nearest-neighbor
  25  *                            sampling.
  26  */
  27
  28 /*
  29  * Include necessary headers...
  30  */
  31
  32 #include "image-private.h"
  33
  34
  35 /*
  36  * Local functions...
  37  */
  38
  39 static void     zoom_bilinear(cups_izoom_t *z, int iy);
  40 static void     zoom_nearest(cups_izoom_t *z, int iy);
  41
  42
  43 /*
  44  * '_cupsImageZoomDelete()' - Free a zoom record...
  45  */
  46
  47 void
  48 _cupsImageZoomDelete(cups_izoom_t *z)   /* I - Zoom record to free */
  49 {
  50   free(z->rows[0]);
  51   free(z->rows[1]);
  52   free(z->in);
  53   free(z);
  54 }
  55
  56
  57 /*
  58  * '_cupsImageZoomFill()' - Fill a zoom record with image data utilizing bilinear
  59  *                         interpolation.
  60  */
  61
  62 void
  63 _cupsImageZoomFill(cups_izoom_t *z,     /* I - Zoom record to fill */
  64                    int     iy)          /* I - Zoom image row */
  65 {
  66   switch (z->type)
  67   {
  68     case CUPS_IZOOM_FAST :
  69         zoom_nearest(z, iy);
  70         break;
  71
  72     default :
  73         zoom_bilinear(z, iy);
  74         break;
  75   }
  76 }
  77
  78
  79 /*
  80  * '_cupsImageZoomNew()' - Allocate a pixel zoom record...
  81  */
  82
  83 cups_izoom_t *
  84 _cupsImageZoomNew(
  85     cups_image_t  *img,                 /* I - cupsImage to zoom */
  86     int           xc0,                  /* I - Upper-lefthand corner */
  87     int           yc0,                  /* I - ... */
  88     int           xc1,                  /* I - Lower-righthand corner */
  89     int           yc1,                  /* I - ... */
  90     int           xsize,                /* I - Final width of image */
  91     int           ysize,                /* I - Final height of image */
  92     int           rotated,              /* I - Non-zero if image is rotated 90 degs */
  93     cups_iztype_t type)                 /* I - Zoom type */
  94 {
  95   cups_izoom_t  *z;                     /* New zoom record */
  96   int           flip;                   /* Flip on X axis? */
  97
  98
  99   if (xsize > CUPS_IMAGE_MAX_WIDTH ||
 100       ysize > CUPS_IMAGE_MAX_HEIGHT ||
 101       (xc1 - xc0) > CUPS_IMAGE_MAX_WIDTH ||
 102       (yc1 - yc0) > CUPS_IMAGE_MAX_HEIGHT)
 103     return (NULL);              /* Protect against integer overflow */
 104
 105   if ((z = (cups_izoom_t *)calloc(1, sizeof(cups_izoom_t))) == NULL)
 106     return (NULL);
 107
 108   z->img     = img;
 109   z->row     = 0;
 110   z->depth   = cupsImageGetDepth(img);
 111   z->rotated = rotated;
 112   z->type    = type;
 113
 114   if (xsize < 0)
 115   {
 116     flip  = 1;
 117     xsize = -xsize;
 118   }
 119   else
 120   {
 121     flip  = 0;
 122   }
 123
 124   if (rotated)
 125   {
 126     z->xorig   = xc1;
 127     z->yorig   = yc0;
 128     z->width   = yc1 - yc0 + 1;
 129     z->height  = xc1 - xc0 + 1;
 130     z->xsize   = xsize;
 131     z->ysize   = ysize;
 132     z->xmod    = z->width % z->xsize;
 133     z->xstep   = z->width / z->xsize;
 134     z->xincr   = 1;
 135     z->ymod    = z->height % z->ysize;
 136     z->ystep   = z->height / z->ysize;
 137     z->yincr   = 1;
 138     z->instep  = z->xstep * z->depth;
 139     z->inincr  = z->xincr * z->depth;
 140
 141     if (z->width < img->ysize)
 142       z->xmax = z->width;
 143     else
 144       z->xmax = z->width - 1;
 145
 146     if (z->height < img->xsize)
 147       z->ymax = z->height;
 148     else
 149       z->ymax = z->height - 1;
 150   }
 151   else
 152   {
 153     z->xorig   = xc0;
 154     z->yorig   = yc0;
 155     z->width   = xc1 - xc0 + 1;
 156     z->height  = yc1 - yc0 + 1;
 157     z->xsize   = xsize;
 158     z->ysize   = ysize;
 159     z->xmod    = z->width % z->xsize;
 160     z->xstep   = z->width / z->xsize;
 161     z->xincr   = 1;
 162     z->ymod    = z->height % z->ysize;
 163     z->ystep   = z->height / z->ysize;
 164     z->yincr   = 1;
 165     z->instep  = z->xstep * z->depth;
 166     z->inincr  = z->xincr * z->depth;
 167
 168     if (z->width < img->xsize)
 169       z->xmax = z->width;
 170     else
 171       z->xmax = z->width - 1;
 172
 173     if (z->height < img->ysize)
 174       z->ymax = z->height;
 175     else
 176       z->ymax = z->height - 1;
 177   }
 178
 179   if (flip)
 180   {
 181     z->instep = -z->instep;
 182     z->inincr = -z->inincr;
 183   }
 184
 185   if ((z->rows[0] = (cups_ib_t *)malloc(z->xsize * z->depth)) == NULL)
 186   {
 187     free(z);
 188     return (NULL);
 189   }
 190
 191   if ((z->rows[1] = (cups_ib_t *)malloc(z->xsize * z->depth)) == NULL)
 192   {
 193     free(z->rows[0]);
 194     free(z);
 195     return (NULL);
 196   }
 197
 198   if ((z->in = (cups_ib_t *)malloc(z->width * z->depth)) == NULL)
 199   {
 200     free(z->rows[0]);
 201     free(z->rows[1]);
 202     free(z);
 203     return (NULL);
 204   }
 205
 206   return (z);
 207 }
 208
 209
 210 /*
 211  * 'zoom_bilinear()' - Fill a zoom record with image data utilizing bilinear
 212  *                     interpolation.
 213  */
 214
 215 static void
 216 zoom_bilinear(cups_izoom_t *z,          /* I - Zoom record to fill */
 217               int          iy)          /* I - Zoom image row */
 218 {
 219   cups_ib_t     *r,                     /* Row pointer */
 220                 *inptr;                 /* Pixel pointer */
 221   int           xerr0,                  /* X error counter */
 222                 xerr1;                  /* ... */
 223   int           ix,
 224                 x,
 225                 count,
 226                 z_depth,
 227                 z_xstep,
 228                 z_xincr,
 229                 z_instep,
 230                 z_inincr,
 231                 z_xmax,
 232                 z_xmod,
 233                 z_xsize;
 234
 235
 236   if (iy > z->ymax)
 237     iy = z->ymax;
 238
 239   z->row ^= 1;
 240
 241   z_depth  = z->depth;
 242   z_xsize  = z->xsize;
 243   z_xmax   = z->xmax;
 244   z_xmod   = z->xmod;
 245   z_xstep  = z->xstep;
 246   z_xincr  = z->xincr;
 247   z_instep = z->instep;
 248   z_inincr = z->inincr;
 249
 250   if (z->rotated)
 251     cupsImageGetCol(z->img, z->xorig - iy, z->yorig, z->width, z->in);
 252   else
 253     cupsImageGetRow(z->img, z->xorig, z->yorig + iy, z->width, z->in);
 254
 255   if (z_inincr < 0)
 256     inptr = z->in + (z->width - 1) * z_depth;
 257   else
 258     inptr = z->in;
 259
 260   for (x = z_xsize, xerr0 = z_xsize, xerr1 = 0, ix = 0, r = z->rows[z->row];
 261        x > 0;
 262        x --)
 263   {
 264     if (ix < z_xmax)
 265     {
 266       for (count = 0; count < z_depth; count ++)
 267         *r++ = (inptr[count] * xerr0 + inptr[z_depth + count] * xerr1) / z_xsize;
 268     }
 269     else
 270     {
 271       for (count = 0; count < z_depth; count ++)
 272         *r++ = inptr[count];
 273     }
 274
 275     ix    += z_xstep;
 276     inptr += z_instep;
 277     xerr0 -= z_xmod;
 278     xerr1 += z_xmod;
 279
 280     if (xerr0 <= 0)
 281     {
 282       xerr0 += z_xsize;
 283       xerr1 -= z_xsize;
 284       ix    += z_xincr;
 285       inptr += z_inincr;
 286     }
 287   }
 288 }
 289
 290
 291 /*
 292  * 'zoom_nearest()' - Fill a zoom record quickly using nearest-neighbor
 293  *                    sampling.
 294  */
 295
 296 static void
 297 zoom_nearest(cups_izoom_t *z,           /* I - Zoom record to fill */
 298              int          iy)           /* I - Zoom image row */
 299 {
 300   cups_ib_t     *r,                     /* Row pointer */
 301                 *inptr;                 /* Pixel pointer */
 302   int           xerr0;                  /* X error counter */
 303   int           ix,
 304                 x,
 305                 count,
 306                 z_depth,
 307                 z_xstep,
 308                 z_xincr,
 309                 z_instep,
 310                 z_inincr,
 311                 z_xmod,
 312                 z_xsize;
 313
 314
 315   if (iy > z->ymax)
 316     iy = z->ymax;
 317
 318   z->row ^= 1;
 319
 320   z_depth  = z->depth;
 321   z_xsize  = z->xsize;
 322   z_xmod   = z->xmod;
 323   z_xstep  = z->xstep;
 324   z_xincr  = z->xincr;
 325   z_instep = z->instep;
 326   z_inincr = z->inincr;
 327
 328   if (z->rotated)
 329     cupsImageGetCol(z->img, z->xorig - iy, z->yorig, z->width, z->in);
 330   else
 331     cupsImageGetRow(z->img, z->xorig, z->yorig + iy, z->width, z->in);
 332
 333   if (z_inincr < 0)
 334     inptr = z->in + (z->width - 1) * z_depth;
 335   else
 336     inptr = z->in;
 337
 338   for (x = z_xsize, xerr0 = z_xsize, ix = 0, r = z->rows[z->row];
 339        x > 0;
 340        x --)
 341   {
 342     for (count = 0; count < z_depth; count ++)
 343       *r++ = inptr[count];
 344
 345     ix    += z_xstep;
 346     inptr += z_instep;
 347     xerr0 -= z_xmod;
 348
 349     if (xerr0 <= 0)
 350     {
 351       xerr0 += z_xsize;
 352       ix    += z_xincr;
 353       inptr += z_inincr;
 354     }
 355   }
 356 }
 357
 358
 359 /*
 360  * End of "$Id: image-zoom.c 6649 2007-07-11 21:46:42Z mike $".
 361  */