rdbmp.c

00001 /*
00002  * rdbmp.c
00003  *
00004  * Copyright (C) 1994-1996, Thomas G. Lane.
00005  * Modified 2009-2010 by Guido Vollbeding.
00006  * This file is part of the Independent JPEG Group's software.
00007  * For conditions of distribution and use, see the accompanying README file.
00008  *
00009  * This file contains routines to read input images in Microsoft "BMP"
00010  * format (MS Windows 3.x, OS/2 1.x, and OS/2 2.x flavors).
00011  * Currently, only 8-bit and 24-bit images are supported, not 1-bit or
00012  * 4-bit (feeding such low-depth images into JPEG would be silly anyway).
00013  * Also, we don't support RLE-compressed files.
00014  *
00015  * These routines may need modification for non-Unix environments or
00016  * specialized applications.  As they stand, they assume input from
00017  * an ordinary stdio stream.  They further assume that reading begins
00018  * at the start of the file; start_input may need work if the
00019  * user interface has already read some data (e.g., to determine that
00020  * the file is indeed BMP format).
00021  *
00022  * This code contributed by James Arthur Boucher.
00023  */
00024 
00025 #include "cdjpeg.h"     /* Common decls for cjpeg/djpeg applications */
00026 
00027 #ifdef BMP_SUPPORTED
00028 
00029 
00030 /* Macros to deal with unsigned chars as efficiently as compiler allows */
00031 
00032 #ifdef HAVE_UNSIGNED_CHAR
00033 typedef unsigned char U_CHAR;
00034 #define UCH(x)  ((int) (x))
00035 #else /* !HAVE_UNSIGNED_CHAR */
00036 #ifdef CHAR_IS_UNSIGNED
00037 typedef char U_CHAR;
00038 #define UCH(x)  ((int) (x))
00039 #else
00040 typedef char U_CHAR;
00041 #define UCH(x)  ((int) (x) & 0xFF)
00042 #endif
00043 #endif /* HAVE_UNSIGNED_CHAR */
00044 
00045 
00046 #define ReadOK(file,buffer,len) (JFREAD(file,buffer,len) == ((size_t) (len)))
00047 
00048 
00049 /* Private version of data source object */
00050 
00051 typedef struct _bmp_source_struct * bmp_source_ptr;
00052 
00053 typedef struct _bmp_source_struct {
00054   struct cjpeg_source_struct pub; /* public fields */
00055 
00056   j_compress_ptr cinfo;     /* back link saves passing separate parm */
00057 
00058   JSAMPARRAY colormap;      /* BMP colormap (converted to my format) */
00059 
00060   jvirt_sarray_ptr whole_image; /* Needed to reverse row order */
00061   JDIMENSION source_row;    /* Current source row number */
00062   JDIMENSION row_width;     /* Physical width of scanlines in file */
00063 
00064   int bits_per_pixel;       /* remembers 8- or 24-bit format */
00065 } bmp_source_struct;
00066 
00067 
00068 LOCAL(int)
00069 read_byte (bmp_source_ptr sinfo)
00070 /* Read next byte from BMP file */
00071 {
00072   register FILE *infile = sinfo->pub.input_file;
00073   register int c;
00074 
00075   if ((c = getc(infile)) == EOF)
00076     ERREXIT(sinfo->cinfo, JERR_INPUT_EOF);
00077   return c;
00078 }
00079 
00080 
00081 LOCAL(void)
00082 read_colormap (bmp_source_ptr sinfo, int cmaplen, int mapentrysize)
00083 /* Read the colormap from a BMP file */
00084 {
00085   int i;
00086 
00087   switch (mapentrysize) {
00088   case 3:
00089     /* BGR format (occurs in OS/2 files) */
00090     for (i = 0; i < cmaplen; i++) {
00091       sinfo->colormap[2][i] = (JSAMPLE) read_byte(sinfo);
00092       sinfo->colormap[1][i] = (JSAMPLE) read_byte(sinfo);
00093       sinfo->colormap[0][i] = (JSAMPLE) read_byte(sinfo);
00094     }
00095     break;
00096   case 4:
00097     /* BGR0 format (occurs in MS Windows files) */
00098     for (i = 0; i < cmaplen; i++) {
00099       sinfo->colormap[2][i] = (JSAMPLE) read_byte(sinfo);
00100       sinfo->colormap[1][i] = (JSAMPLE) read_byte(sinfo);
00101       sinfo->colormap[0][i] = (JSAMPLE) read_byte(sinfo);
00102       (void) read_byte(sinfo);
00103     }
00104     break;
00105   default:
00106     ERREXIT(sinfo->cinfo, JERR_BMP_BADCMAP);
00107     break;
00108   }
00109 }
00110 
00111 
00112 /*
00113  * Read one row of pixels.
00114  * The image has been read into the whole_image array, but is otherwise
00115  * unprocessed.  We must read it out in top-to-bottom row order, and if
00116  * it is an 8-bit image, we must expand colormapped pixels to 24bit format.
00117  */
00118 
00119 METHODDEF(JDIMENSION)
00120 get_8bit_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
00121 /* This version is for reading 8-bit colormap indexes */
00122 {
00123   bmp_source_ptr source = (bmp_source_ptr) sinfo;
00124   register JSAMPARRAY colormap = source->colormap;
00125   JSAMPARRAY image_ptr;
00126   register int t;
00127   register JSAMPROW inptr, outptr;
00128   register JDIMENSION col;
00129 
00130   /* Fetch next row from virtual array */
00131   source->source_row--;
00132   image_ptr = (*cinfo->mem->access_virt_sarray)
00133     ((j_common_ptr) cinfo, source->whole_image,
00134      source->source_row, (JDIMENSION) 1, FALSE);
00135 
00136   /* Expand the colormap indexes to real data */
00137   inptr = image_ptr[0];
00138   outptr = source->pub.buffer[0];
00139   for (col = cinfo->image_width; col > 0; col--) {
00140     t = GETJSAMPLE(*inptr++);
00141     *outptr++ = colormap[0][t]; /* can omit GETJSAMPLE() safely */
00142     *outptr++ = colormap[1][t];
00143     *outptr++ = colormap[2][t];
00144   }
00145 
00146   return 1;
00147 }
00148 
00149 
00150 METHODDEF(JDIMENSION)
00151 get_24bit_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
00152 /* This version is for reading 24-bit pixels */
00153 {
00154   bmp_source_ptr source = (bmp_source_ptr) sinfo;
00155   JSAMPARRAY image_ptr;
00156   register JSAMPROW inptr, outptr;
00157   register JDIMENSION col;
00158 
00159   /* Fetch next row from virtual array */
00160   source->source_row--;
00161   image_ptr = (*cinfo->mem->access_virt_sarray)
00162     ((j_common_ptr) cinfo, source->whole_image,
00163      source->source_row, (JDIMENSION) 1, FALSE);
00164 
00165   /* Transfer data.  Note source values are in BGR order
00166    * (even though Microsoft's own documents say the opposite).
00167    */
00168   inptr = image_ptr[0];
00169   outptr = source->pub.buffer[0];
00170   for (col = cinfo->image_width; col > 0; col--) {
00171     outptr[2] = *inptr++;   /* can omit GETJSAMPLE() safely */
00172     outptr[1] = *inptr++;
00173     outptr[0] = *inptr++;
00174     outptr += 3;
00175   }
00176 
00177   return 1;
00178 }
00179 
00180 
00181 METHODDEF(JDIMENSION)
00182 get_32bit_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
00183 /* This version is for reading 32-bit pixels */
00184 {
00185   bmp_source_ptr source = (bmp_source_ptr) sinfo;
00186   JSAMPARRAY image_ptr;
00187   register JSAMPROW inptr, outptr;
00188   register JDIMENSION col;
00189 
00190   /* Fetch next row from virtual array */
00191   source->source_row--;
00192   image_ptr = (*cinfo->mem->access_virt_sarray)
00193     ((j_common_ptr) cinfo, source->whole_image,
00194      source->source_row, (JDIMENSION) 1, FALSE);
00195   /* Transfer data.  Note source values are in BGR order
00196    * (even though Microsoft's own documents say the opposite).
00197    */
00198   inptr = image_ptr[0];
00199   outptr = source->pub.buffer[0];
00200   for (col = cinfo->image_width; col > 0; col--) {
00201     outptr[2] = *inptr++;   /* can omit GETJSAMPLE() safely */
00202     outptr[1] = *inptr++;
00203     outptr[0] = *inptr++;
00204     inptr++;            /* skip the 4th byte (Alpha channel) */
00205     outptr += 3;
00206   }
00207 
00208   return 1;
00209 }
00210 
00211 
00212 /*
00213  * This method loads the image into whole_image during the first call on
00214  * get_pixel_rows.  The get_pixel_rows pointer is then adjusted to call
00215  * get_8bit_row, get_24bit_row, or get_32bit_row on subsequent calls.
00216  */
00217 
00218 METHODDEF(JDIMENSION)
00219 preload_image (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
00220 {
00221   bmp_source_ptr source = (bmp_source_ptr) sinfo;
00222   register FILE *infile = source->pub.input_file;
00223   register int c;
00224   register JSAMPROW out_ptr;
00225   JSAMPARRAY image_ptr;
00226   JDIMENSION row, col;
00227   cd_progress_ptr progress = (cd_progress_ptr) cinfo->progress;
00228 
00229   /* Read the data into a virtual array in input-file row order. */
00230   for (row = 0; row < cinfo->image_height; row++) {
00231     if (progress != NULL) {
00232       progress->pub.pass_counter = (long) row;
00233       progress->pub.pass_limit = (long) cinfo->image_height;
00234       (*progress->pub.progress_monitor) ((j_common_ptr) cinfo);
00235     }
00236     image_ptr = (*cinfo->mem->access_virt_sarray)
00237       ((j_common_ptr) cinfo, source->whole_image,
00238        row, (JDIMENSION) 1, TRUE);
00239     out_ptr = image_ptr[0];
00240     for (col = source->row_width; col > 0; col--) {
00241       /* inline copy of read_byte() for speed */
00242       if ((c = getc(infile)) == EOF)
00243     ERREXIT(cinfo, JERR_INPUT_EOF);
00244       *out_ptr++ = (JSAMPLE) c;
00245     }
00246   }
00247   if (progress != NULL)
00248     progress->completed_extra_passes++;
00249 
00250   /* Set up to read from the virtual array in top-to-bottom order */
00251   switch (source->bits_per_pixel) {
00252   case 8:
00253     source->pub.get_pixel_rows = get_8bit_row;
00254     break;
00255   case 24:
00256     source->pub.get_pixel_rows = get_24bit_row;
00257     break;
00258   case 32:
00259     source->pub.get_pixel_rows = get_32bit_row;
00260     break;
00261   default:
00262     ERREXIT(cinfo, JERR_BMP_BADDEPTH);
00263   }
00264   source->source_row = cinfo->image_height;
00265 
00266   /* And read the first row */
00267   return (*source->pub.get_pixel_rows) (cinfo, sinfo);
00268 }
00269 
00270 
00271 /*
00272  * Read the file header; return image size and component count.
00273  */
00274 
00275 METHODDEF(void)
00276 start_input_bmp (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
00277 {
00278   bmp_source_ptr source = (bmp_source_ptr) sinfo;
00279   U_CHAR bmpfileheader[14];
00280   U_CHAR bmpinfoheader[64];
00281 #define GET_2B(array,offset)  ((unsigned int) UCH(array[offset]) + \
00282                    (((unsigned int) UCH(array[offset+1])) << 8))
00283 #define GET_4B(array,offset)  ((INT32) UCH(array[offset]) + \
00284                    (((INT32) UCH(array[offset+1])) << 8) + \
00285                    (((INT32) UCH(array[offset+2])) << 16) + \
00286                    (((INT32) UCH(array[offset+3])) << 24))
00287   INT32 bfOffBits;
00288   INT32 headerSize;
00289   INT32 biWidth;
00290   INT32 biHeight;
00291   unsigned int biPlanes;
00292   INT32 biCompression;
00293   INT32 biXPelsPerMeter,biYPelsPerMeter;
00294   INT32 biClrUsed = 0;
00295   int mapentrysize = 0;     /* 0 indicates no colormap */
00296   INT32 bPad;
00297   JDIMENSION row_width;
00298 
00299   /* Read and verify the bitmap file header */
00300   if (! ReadOK(source->pub.input_file, bmpfileheader, 14))
00301     ERREXIT(cinfo, JERR_INPUT_EOF);
00302   if (GET_2B(bmpfileheader,0) != 0x4D42) /* 'BM' */
00303     ERREXIT(cinfo, JERR_BMP_NOT);
00304   bfOffBits = (INT32) GET_4B(bmpfileheader,10);
00305   /* We ignore the remaining fileheader fields */
00306 
00307   /* The infoheader might be 12 bytes (OS/2 1.x), 40 bytes (Windows),
00308    * or 64 bytes (OS/2 2.x).  Check the first 4 bytes to find out which.
00309    */
00310   if (! ReadOK(source->pub.input_file, bmpinfoheader, 4))
00311     ERREXIT(cinfo, JERR_INPUT_EOF);
00312   headerSize = (INT32) GET_4B(bmpinfoheader,0);
00313   if (headerSize < 12 || headerSize > 64)
00314     ERREXIT(cinfo, JERR_BMP_BADHEADER);
00315   if (! ReadOK(source->pub.input_file, bmpinfoheader+4, headerSize-4))
00316     ERREXIT(cinfo, JERR_INPUT_EOF);
00317 
00318   switch ((int) headerSize) {
00319   case 12:
00320     /* Decode OS/2 1.x header (Microsoft calls this a BITMAPCOREHEADER) */
00321     biWidth = (INT32) GET_2B(bmpinfoheader,4);
00322     biHeight = (INT32) GET_2B(bmpinfoheader,6);
00323     biPlanes = GET_2B(bmpinfoheader,8);
00324     source->bits_per_pixel = (int) GET_2B(bmpinfoheader,10);
00325 
00326     switch (source->bits_per_pixel) {
00327     case 8:         /* colormapped image */
00328       mapentrysize = 3;     /* OS/2 uses RGBTRIPLE colormap */
00329       TRACEMS2(cinfo, 1, JTRC_BMP_OS2_MAPPED, (int) biWidth, (int) biHeight);
00330       break;
00331     case 24:            /* RGB image */
00332       TRACEMS2(cinfo, 1, JTRC_BMP_OS2, (int) biWidth, (int) biHeight);
00333       break;
00334     default:
00335       ERREXIT(cinfo, JERR_BMP_BADDEPTH);
00336       break;
00337     }
00338     break;
00339   case 40:
00340   case 64:
00341     /* Decode Windows 3.x header (Microsoft calls this a BITMAPINFOHEADER) */
00342     /* or OS/2 2.x header, which has additional fields that we ignore */
00343     biWidth = GET_4B(bmpinfoheader,4);
00344     biHeight = GET_4B(bmpinfoheader,8);
00345     biPlanes = GET_2B(bmpinfoheader,12);
00346     source->bits_per_pixel = (int) GET_2B(bmpinfoheader,14);
00347     biCompression = GET_4B(bmpinfoheader,16);
00348     biXPelsPerMeter = GET_4B(bmpinfoheader,24);
00349     biYPelsPerMeter = GET_4B(bmpinfoheader,28);
00350     biClrUsed = GET_4B(bmpinfoheader,32);
00351     /* biSizeImage, biClrImportant fields are ignored */
00352 
00353     switch (source->bits_per_pixel) {
00354     case 8:         /* colormapped image */
00355       mapentrysize = 4;     /* Windows uses RGBQUAD colormap */
00356       TRACEMS2(cinfo, 1, JTRC_BMP_MAPPED, (int) biWidth, (int) biHeight);
00357       break;
00358     case 24:            /* RGB image */
00359       TRACEMS2(cinfo, 1, JTRC_BMP, (int) biWidth, (int) biHeight);
00360       break;
00361     case 32:            /* RGB image + Alpha channel */
00362       TRACEMS2(cinfo, 1, JTRC_BMP, (int) biWidth, (int) biHeight);
00363       break;
00364     default:
00365       ERREXIT(cinfo, JERR_BMP_BADDEPTH);
00366       break;
00367     }
00368     if (biCompression != 0)
00369       ERREXIT(cinfo, JERR_BMP_COMPRESSED);
00370 
00371     if (biXPelsPerMeter > 0 && biYPelsPerMeter > 0) {
00372       /* Set JFIF density parameters from the BMP data */
00373       cinfo->X_density = (UINT16) (biXPelsPerMeter/100); /* 100 cm per meter */
00374       cinfo->Y_density = (UINT16) (biYPelsPerMeter/100);
00375       cinfo->density_unit = 2;  /* dots/cm */
00376     }
00377     break;
00378   default:
00379     ERREXIT(cinfo, JERR_BMP_BADHEADER);
00380     return;
00381   }
00382 
00383   if (biWidth <= 0 || biHeight <= 0)
00384     ERREXIT(cinfo, JERR_BMP_EMPTY);
00385   if (biPlanes != 1)
00386     ERREXIT(cinfo, JERR_BMP_BADPLANES);
00387 
00388   /* Compute distance to bitmap data --- will adjust for colormap below */
00389   bPad = bfOffBits - (headerSize + 14);
00390 
00391   /* Read the colormap, if any */
00392   if (mapentrysize > 0) {
00393     if (biClrUsed <= 0)
00394       biClrUsed = 256;      /* assume it's 256 */
00395     else if (biClrUsed > 256)
00396       ERREXIT(cinfo, JERR_BMP_BADCMAP);
00397     /* Allocate space to store the colormap */
00398     source->colormap = (*cinfo->mem->alloc_sarray)
00399       ((j_common_ptr) cinfo, JPOOL_IMAGE,
00400        (JDIMENSION) biClrUsed, (JDIMENSION) 3);
00401     /* and read it from the file */
00402     read_colormap(source, (int) biClrUsed, mapentrysize);
00403     /* account for size of colormap */
00404     bPad -= biClrUsed * mapentrysize;
00405   }
00406 
00407   /* Skip any remaining pad bytes */
00408   if (bPad < 0)         /* incorrect bfOffBits value? */
00409     ERREXIT(cinfo, JERR_BMP_BADHEADER);
00410   while (--bPad >= 0) {
00411     (void) read_byte(source);
00412   }
00413 
00414   /* Compute row width in file, including padding to 4-byte boundary */
00415   if (source->bits_per_pixel == 24)
00416     row_width = (JDIMENSION) (biWidth * 3);
00417   else if (source->bits_per_pixel == 32)
00418     row_width = (JDIMENSION) (biWidth * 4);
00419   else
00420     row_width = (JDIMENSION) biWidth;
00421   while ((row_width & 3) != 0) row_width++;
00422   source->row_width = row_width;
00423 
00424   /* Allocate space for inversion array, prepare for preload pass */
00425   source->whole_image = (*cinfo->mem->request_virt_sarray)
00426     ((j_common_ptr) cinfo, JPOOL_IMAGE, FALSE,
00427      row_width, (JDIMENSION) biHeight, (JDIMENSION) 1);
00428   source->pub.get_pixel_rows = preload_image;
00429   if (cinfo->progress != NULL) {
00430     cd_progress_ptr progress = (cd_progress_ptr) cinfo->progress;
00431     progress->total_extra_passes++; /* count file input as separate pass */
00432   }
00433 
00434   /* Allocate one-row buffer for returned data */
00435   source->pub.buffer = (*cinfo->mem->alloc_sarray)
00436     ((j_common_ptr) cinfo, JPOOL_IMAGE,
00437      (JDIMENSION) (biWidth * 3), (JDIMENSION) 1);
00438   source->pub.buffer_height = 1;
00439 
00440   cinfo->in_color_space = JCS_RGB;
00441   cinfo->input_components = 3;
00442   cinfo->data_precision = 8;
00443   cinfo->image_width = (JDIMENSION) biWidth;
00444   cinfo->image_height = (JDIMENSION) biHeight;
00445 }
00446 
00447 
00448 /*
00449  * Finish up at the end of the file.
00450  */
00451 
00452 METHODDEF(void)
00453 finish_input_bmp (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
00454 {
00455   /* no work */
00456 }
00457 
00458 
00459 /*
00460  * The module selection routine for BMP format input.
00461  */
00462 
00463 GLOBAL(cjpeg_source_ptr)
00464 jinit_read_bmp (j_compress_ptr cinfo)
00465 {
00466   bmp_source_ptr source;
00467 
00468   /* Create module interface object */
00469   source = (bmp_source_ptr)
00470       (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
00471                   SIZEOF(bmp_source_struct));
00472   source->cinfo = cinfo;    /* make back link for subroutines */
00473   /* Fill in method ptrs, except get_pixel_rows which start_input sets */
00474   source->pub.start_input = start_input_bmp;
00475   source->pub.finish_input = finish_input_bmp;
00476 
00477   return (cjpeg_source_ptr) source;
00478 }
00479 
00480 #endif /* BMP_SUPPORTED */