Modules/imgfile.c

   1
   2 /* IMGFILE module - Interface to sgi libimage */
   3
   4 /* XXX This module should be done better at some point. It should return
   5 ** an object of image file class, and have routines to manipulate these
   6 ** image files in a neater way (so you can get rgb images off a greyscale
   7 ** file, for instance, or do a straight display without having to get the
   8 ** image bits into python, etc).
   9 **
  10 ** Warning: this module is very non-reentrant (esp. the readscaled stuff)
  11 */
  12
  13 #include "Python.h"
  14
  15 #include <gl/image.h>
  16
  17 #include "/usr/people/4Dgifts/iristools/include/izoom.h"
  18
  19 /* Bunch of missing extern decls; keep gcc -Wall happy... */
  20 extern void i_seterror();
  21 extern void iclose();
  22 extern void filterzoom();
  23 extern void putrow();
  24 extern void getrow();
  25
  26 static PyObject * ImgfileError; /* Exception we raise for various trouble */
  27
  28 static int top_to_bottom;       /* True if we want top-to-bottom images */
  29
  30 /* The image library does not always call the error hander :-(,
  31    therefore we have a global variable indicating that it was called.
  32    It is cleared by imgfile_open(). */
  33
  34 static int error_called;
  35
  36
  37 /* The error handler */
  38
  39 static void
  40 imgfile_error(char *str)
  41 {
  42         PyErr_SetString(ImgfileError, str);
  43         error_called = 1;
  44         return; /* To imglib, which will return a failure indicator */
  45 }
  46
  47
  48 /* Open an image file and return a pointer to it.
  49    Make sure we raise an exception if we fail. */
  50
  51 static IMAGE *
  52 imgfile_open(char *fname)
  53 {
  54         IMAGE *image;
  55         i_seterror(imgfile_error);
  56         error_called = 0;
  57         errno = 0;
  58         if ( (image = iopen(fname, "r")) == NULL ) {
  59                 /* Error may already be set by imgfile_error */
  60                 if ( !error_called ) {
  61                         if (errno)
  62                                 PyErr_SetFromErrno(ImgfileError);
  63                         else
  64                                 PyErr_SetString(ImgfileError,
  65                                                 "Can't open image file");
  66                 }
  67                 return NULL;
  68         }
  69         return image;
  70 }
  71
  72 static PyObject *
  73 imgfile_ttob(PyObject *self, PyObject *args)
  74 {
  75         int newval;
  76         PyObject *rv;
  77
  78         if (!PyArg_ParseTuple(args, "i:ttob", &newval))
  79                 return NULL;
  80         rv = PyInt_FromLong(top_to_bottom);
  81         top_to_bottom = newval;
  82         return rv;
  83 }
  84
  85 static PyObject *
  86 imgfile_read(PyObject *self, PyObject *args)
  87 {
  88         char *fname;
  89         PyObject *rv;
  90         int xsize, ysize, zsize;
  91         char *cdatap;
  92         long *idatap;
  93         static short rs[8192], gs[8192], bs[8192];
  94         int x, y;
  95         IMAGE *image;
  96         int yfirst, ylast, ystep;
  97
  98         if ( !PyArg_ParseTuple(args, "s:read", &fname) )
  99                 return NULL;
 100
 101         if ( (image = imgfile_open(fname)) == NULL )
 102                 return NULL;
 103
 104         if ( image->colormap != CM_NORMAL ) {
 105                 iclose(image);
 106                 PyErr_SetString(ImgfileError,
 107                                 "Can only handle CM_NORMAL images");
 108                 return NULL;
 109         }
 110         if ( BPP(image->type) != 1 ) {
 111                 iclose(image);
 112                 PyErr_SetString(ImgfileError,
 113                                 "Can't handle imgfiles with bpp!=1");
 114                 return NULL;
 115         }
 116         xsize = image->xsize;
 117         ysize = image->ysize;
 118         zsize = image->zsize;
 119         if ( zsize != 1 && zsize != 3) {
 120                 iclose(image);
 121                 PyErr_SetString(ImgfileError,
 122                                 "Can only handle 1 or 3 byte pixels");
 123                 return NULL;
 124         }
 125         if ( xsize > 8192 ) {
 126                 iclose(image);
 127                 PyErr_SetString(ImgfileError,
 128                                 "Can't handle image with > 8192 columns");
 129                 return NULL;
 130         }
 131
 132         if ( zsize == 3 ) zsize = 4;
 133         rv = PyString_FromStringAndSize((char *)NULL, xsize*ysize*zsize);
 134         if ( rv == NULL ) {
 135                 iclose(image);
 136                 return NULL;
 137         }
 138         cdatap = PyString_AsString(rv);
 139         idatap = (long *)cdatap;
 140
 141         if (top_to_bottom) {
 142                 yfirst = ysize-1;
 143                 ylast = -1;
 144                 ystep = -1;
 145         } else {
 146                 yfirst = 0;
 147                 ylast = ysize;
 148                 ystep = 1;
 149         }
 150         for ( y=yfirst; y != ylast && !error_called; y += ystep ) {
 151                 if ( zsize == 1 ) {
 152                         getrow(image, rs, y, 0);
 153                         for(x=0; x<xsize; x++ )
 154                                 *cdatap++ = rs[x];
 155                 } else {
 156                         getrow(image, rs, y, 0);
 157                         getrow(image, gs, y, 1);
 158                         getrow(image, bs, y, 2);
 159                         for(x=0; x<xsize; x++ )
 160                                 *idatap++ = (rs[x] & 0xff)  |
 161                                         ((gs[x] & 0xff)<<8) |
 162                                         ((bs[x] & 0xff)<<16);
 163                 }
 164         }
 165         iclose(image);
 166         if ( error_called ) {
 167                 Py_DECREF(rv);
 168                 return NULL;
 169         }
 170         return rv;
 171 }
 172
 173 static IMAGE *glob_image;
 174 static long *glob_datap;
 175 static int glob_width, glob_z, glob_ysize;
 176
 177 static void
 178 xs_get(short *buf, int y)
 179 {
 180         if (top_to_bottom)
 181                 getrow(glob_image, buf, (glob_ysize-1-y), glob_z);
 182         else
 183                 getrow(glob_image, buf, y, glob_z);
 184 }
 185
 186 static void
 187 xs_put_c(short *buf, int y)
 188 {
 189         char *datap = (char *)glob_datap + y*glob_width;
 190         int width = glob_width;
 191
 192         while ( width-- )
 193                 *datap++ = (*buf++) & 0xff;
 194 }
 195
 196 static void
 197 xs_put_0(short *buf, int y)
 198 {
 199         long *datap = glob_datap + y*glob_width;
 200         int width = glob_width;
 201
 202         while ( width-- )
 203                 *datap++ = (*buf++) & 0xff;
 204 }
 205 static void
 206 xs_put_12(short *buf, int y)
 207 {
 208         long *datap = glob_datap + y*glob_width;
 209         int width = glob_width;
 210
 211         while ( width-- )
 212                 *datap++ |= ((*buf++) & 0xff) << (glob_z*8);
 213 }
 214
 215 static void
 216 xscale(IMAGE *image, int xsize, int ysize, int zsize,
 217        long *datap, int xnew, int ynew, int fmode, double blur)
 218 {
 219         glob_image = image;
 220         glob_datap = datap;
 221         glob_width = xnew;
 222         glob_ysize = ysize;
 223         if ( zsize == 1 ) {
 224                 glob_z = 0;
 225                 filterzoom(xs_get, xs_put_c, xsize, ysize,
 226                            xnew, ynew, fmode, blur);
 227         } else {
 228                 glob_z = 0;
 229                 filterzoom(xs_get, xs_put_0, xsize, ysize,
 230                            xnew, ynew, fmode, blur);
 231                 glob_z = 1;
 232                 filterzoom(xs_get, xs_put_12, xsize, ysize,
 233                            xnew, ynew, fmode, blur);
 234                 glob_z = 2;
 235                 filterzoom(xs_get, xs_put_12, xsize, ysize,
 236                            xnew, ynew, fmode, blur);
 237         }
 238 }
 239
 240
 241 static PyObject *
 242 imgfile_readscaled(PyObject *self, PyObject *args)
 243 {
 244         char *fname;
 245         PyObject *rv;
 246         int xsize, ysize, zsize;
 247         char *cdatap;
 248         long *idatap;
 249         static short rs[8192], gs[8192], bs[8192];
 250         int x, y;
 251         int xwtd, ywtd, xorig, yorig;
 252         float xfac, yfac;
 253         IMAGE *image;
 254         char *filter;
 255         double blur = 1.0;
 256         int extended;
 257         int fmode = 0;
 258         int yfirst, ylast, ystep;
 259
 260         /*
 261         ** Parse args. Funny, since arg 4 and 5 are optional
 262         ** (filter name and blur factor). Also, 4 or 5 arguments indicates
 263         ** extended scale algorithm in stead of simple-minded pixel drop/dup.
 264         */
 265         extended = PyTuple_Size(args) >= 4;
 266         if ( !PyArg_ParseTuple(args, "sii|sd",
 267                                &fname, &xwtd, &ywtd, &filter, &blur) )
 268                 return NULL;
 269
 270         /*
 271         ** Check parameters, open file and check type, rows, etc.
 272         */
 273         if ( extended ) {
 274                 if ( strcmp(filter, "impulse") == 0 )
 275                         fmode = IMPULSE;
 276                 else if ( strcmp( filter, "box") == 0 )
 277                         fmode = BOX;
 278                 else if ( strcmp( filter, "triangle") == 0 )
 279                         fmode = TRIANGLE;
 280                 else if ( strcmp( filter, "quadratic") == 0 )
 281                         fmode = QUADRATIC;
 282                 else if ( strcmp( filter, "gaussian") == 0 )
 283                         fmode = GAUSSIAN;
 284                 else {
 285                         PyErr_SetString(ImgfileError, "Unknown filter type");
 286                         return NULL;
 287                 }
 288         }
 289
 290         if ( (image = imgfile_open(fname)) == NULL )
 291                 return NULL;
 292
 293         if ( image->colormap != CM_NORMAL ) {
 294                 iclose(image);
 295                 PyErr_SetString(ImgfileError,
 296                                 "Can only handle CM_NORMAL images");
 297                 return NULL;
 298         }
 299         if ( BPP(image->type) != 1 ) {
 300                 iclose(image);
 301                 PyErr_SetString(ImgfileError,
 302                                 "Can't handle imgfiles with bpp!=1");
 303                 return NULL;
 304         }
 305         xsize = image->xsize;
 306         ysize = image->ysize;
 307         zsize = image->zsize;
 308         if ( zsize != 1 && zsize != 3) {
 309                 iclose(image);
 310                 PyErr_SetString(ImgfileError,
 311                                 "Can only handle 1 or 3 byte pixels");
 312                 return NULL;
 313         }
 314         if ( xsize > 8192 ) {
 315                 iclose(image);
 316                 PyErr_SetString(ImgfileError,
 317                                 "Can't handle image with > 8192 columns");
 318                 return NULL;
 319         }
 320
 321         if ( zsize == 3 ) zsize = 4;
 322         rv = PyString_FromStringAndSize(NULL, xwtd*ywtd*zsize);
 323         if ( rv == NULL ) {
 324                 iclose(image);
 325                 return NULL;
 326         }
 327         PyFPE_START_PROTECT("readscaled", return 0)
 328         xfac = (float)xsize/(float)xwtd;
 329         yfac = (float)ysize/(float)ywtd;
 330         PyFPE_END_PROTECT(yfac)
 331         cdatap = PyString_AsString(rv);
 332         idatap = (long *)cdatap;
 333
 334         if ( extended ) {
 335                 xscale(image, xsize, ysize, zsize,
 336                        idatap, xwtd, ywtd, fmode, blur);
 337         } else {
 338                 if (top_to_bottom) {
 339                         yfirst = ywtd-1;
 340                         ylast = -1;
 341                         ystep = -1;
 342                 } else {
 343                         yfirst = 0;
 344                         ylast = ywtd;
 345                         ystep = 1;
 346                 }
 347                 for ( y=yfirst; y != ylast && !error_called; y += ystep ) {
 348                         yorig = (int)(y*yfac);
 349                         if ( zsize == 1 ) {
 350                                 getrow(image, rs, yorig, 0);
 351                                 for(x=0; x<xwtd; x++ ) {
 352                                         *cdatap++ = rs[(int)(x*xfac)];
 353                                 }
 354                         } else {
 355                                 getrow(image, rs, yorig, 0);
 356                                 getrow(image, gs, yorig, 1);
 357                                 getrow(image, bs, yorig, 2);
 358                                 for(x=0; x<xwtd; x++ ) {
 359                                         xorig = (int)(x*xfac);
 360                                         *idatap++ = (rs[xorig] & 0xff)  |
 361                                                 ((gs[xorig] & 0xff)<<8) |
 362                                                 ((bs[xorig] & 0xff)<<16);
 363                                 }
 364                         }
 365                 }
 366         }
 367         iclose(image);
 368         if ( error_called ) {
 369                 Py_DECREF(rv);
 370                 return NULL;
 371         }
 372         return rv;
 373 }
 374
 375 static PyObject *
 376 imgfile_getsizes(PyObject *self, PyObject *args)
 377 {
 378         char *fname;
 379         PyObject *rv;
 380         IMAGE *image;
 381
 382         if ( !PyArg_ParseTuple(args, "s:getsizes", &fname) )
 383                 return NULL;
 384
 385         if ( (image = imgfile_open(fname)) == NULL )
 386                 return NULL;
 387         rv = Py_BuildValue("(iii)", image->xsize, image->ysize, image->zsize);
 388         iclose(image);
 389         return rv;
 390 }
 391
 392 static PyObject *
 393 imgfile_write(PyObject *self, PyObject *args)
 394 {
 395         IMAGE *image;
 396         char *fname;
 397         int xsize, ysize, zsize, len;
 398         char *cdatap;
 399         long *idatap;
 400         short rs[8192], gs[8192], bs[8192];
 401         short r, g, b;
 402         long rgb;
 403         int x, y;
 404         int yfirst, ylast, ystep;
 405
 406
 407         if ( !PyArg_ParseTuple(args, "ss#iii:write",
 408                           &fname, &cdatap, &len, &xsize, &ysize, &zsize) )
 409                 return NULL;
 410
 411         if ( zsize != 1 && zsize != 3 ) {
 412                 PyErr_SetString(ImgfileError,
 413                                 "Can only handle 1 or 3 byte pixels");
 414                 return NULL;
 415         }
 416         if ( len != xsize * ysize * (zsize == 1 ? 1 : 4) ) {
 417                 PyErr_SetString(ImgfileError, "Data does not match sizes");
 418                 return NULL;
 419         }
 420         if ( xsize > 8192 ) {
 421                 PyErr_SetString(ImgfileError,
 422                                 "Can't handle image with > 8192 columns");
 423                 return NULL;
 424         }
 425
 426         error_called = 0;
 427         errno = 0;
 428         image =iopen(fname, "w", RLE(1), 3, xsize, ysize, zsize);
 429         if ( image == 0 ) {
 430                 if ( ! error_called ) {
 431                         if (errno)
 432                                 PyErr_SetFromErrno(ImgfileError);
 433                         else
 434                                 PyErr_SetString(ImgfileError,
 435                                                 "Can't create image file");
 436                 }
 437                 return NULL;
 438         }
 439
 440         idatap = (long *)cdatap;
 441
 442         if (top_to_bottom) {
 443                 yfirst = ysize-1;
 444                 ylast = -1;
 445                 ystep = -1;
 446         } else {
 447                 yfirst = 0;
 448                 ylast = ysize;
 449                 ystep = 1;
 450         }
 451         for ( y=yfirst; y != ylast && !error_called; y += ystep ) {
 452                 if ( zsize == 1 ) {
 453                         for( x=0; x<xsize; x++ )
 454                                 rs[x] = *cdatap++;
 455                         putrow(image, rs, y, 0);
 456                 } else {
 457                         for( x=0; x<xsize; x++ ) {
 458                                 rgb = *idatap++;
 459                                 r = rgb & 0xff;
 460                                 g = (rgb >> 8 ) & 0xff;
 461                                 b = (rgb >> 16 ) & 0xff;
 462                                 rs[x] = r;
 463                                 gs[x] = g;
 464                                 bs[x] = b;
 465                         }
 466                         putrow(image, rs, y, 0);
 467                         putrow(image, gs, y, 1);
 468                         putrow(image, bs, y, 2);
 469                 }
 470         }
 471         iclose(image);
 472         if ( error_called )
 473                 return NULL;
 474         Py_INCREF(Py_None);
 475         return Py_None;
 476
 477 }
 478
 479
 480 static PyMethodDef imgfile_methods[] = {
 481         { "getsizes",   imgfile_getsizes, METH_VARARGS },
 482         { "read",       imgfile_read, METH_VARARGS },
 483         { "readscaled", imgfile_readscaled, METH_VARARGS},
 484         { "write",      imgfile_write, METH_VARARGS },
 485         { "ttob",       imgfile_ttob, METH_VARARGS },
 486         { NULL,         NULL } /* Sentinel */
 487 };
 488
 489
 490 void
 491 initimgfile(void)
 492 {
 493         PyObject *m, *d;
 494         m = Py_InitModule("imgfile", imgfile_methods);
 495         if (m == NULL)
 496                 return;
 497         d = PyModule_GetDict(m);
 498         ImgfileError = PyErr_NewException("imgfile.error", NULL, NULL);
 499         if (ImgfileError != NULL)
 500                 PyDict_SetItemString(d, "error", ImgfileError);
 501 }
 502
 503
 504