testbmp.c

This is code tutorial for image processing include:histogram,sketon....

   bmheader->colorsimp    = 256;

   file_header->filetype     = 0x4D42;
   file_header->reserved1    =  0;
   file_header->reserved2    =  0;
   file_header->bitmapoffset = 14 + 
                               bmheader->size +
                               bmheader->colorsused*4;
   file_header->filesize     = file_header->bitmapoffset +
                               bmheader->sizeofbitmap;

   if((fp = fopen(file_name, "wb")) == NULL){
      printf("\nERROR Could not create file %s",
             file_name);
      exit(2);
   }

      /*********************************************
      *
      *   Write the 14-byte bmp file header.
      *
      *********************************************/

   insert_ushort_into_buffer(buffer, 0, file_header->filetype);
   fwrite(buffer, 1, 2, fp);

   insert_ulong_into_buffer(buffer, 0, file_header->filesize);
   fwrite(buffer, 1, 4, fp);

   insert_short_into_buffer(buffer, 0, file_header->reserved1);
   fwrite(buffer, 1, 2, fp);

   insert_short_into_buffer(buffer, 0, file_header->reserved2);
   fwrite(buffer, 1, 2, fp);

   insert_ulong_into_buffer(buffer, 0, file_header->bitmapoffset);
   fwrite(buffer, 1, 4, fp);


      /*********************************************
      *
      *   Write the 40-byte bit map header.
      *
      *********************************************/

   insert_ulong_into_buffer(buffer, 0, bmheader->size);
   fwrite(buffer, 1, 4, fp);

   insert_long_into_buffer(buffer, 0, bmheader->width);
   fwrite(buffer, 1, 4, fp);

   insert_long_into_buffer(buffer, 0, bmheader->height);
   fwrite(buffer, 1, 4, fp);

   insert_ushort_into_buffer(buffer, 0, bmheader->planes);
   fwrite(buffer, 1, 2, fp);

   insert_ushort_into_buffer(buffer, 0, bmheader->bitsperpixel);
   fwrite(buffer, 1, 2, fp);

   insert_ulong_into_buffer(buffer, 0, bmheader->compression);
   fwrite(buffer, 1, 4, fp);

   insert_ulong_into_buffer(buffer, 0, bmheader->sizeofbitmap);
   fwrite(buffer, 1, 4, fp);

   insert_ulong_into_buffer(buffer, 0, bmheader->horzres);
   fwrite(buffer, 1, 4, fp);

   insert_ulong_into_buffer(buffer, 0, bmheader->vertres);
   fwrite(buffer, 1, 4, fp);

   insert_ulong_into_buffer(buffer, 0, bmheader->colorsused);
   fwrite(buffer, 1, 4, fp);

   insert_ulong_into_buffer(buffer, 0, bmheader->colorsimp);
   fwrite(buffer, 1, 4, fp);

      /*********************************************
      *
      *   Write a blank color table.
      *   It has 256 entries (number of colors)
      *   that are each 4 bytes.
      *
      *********************************************/

   buffer[0] = 0x00;

   for(i=0; i<(256*4); i++)
      fwrite(buffer, 1, 1, fp);

      /*********************************************
      *
      *   Write a zero image.  
      *
      *********************************************/

   buffer[0] = 0x00;

   for(i=0; i<bmheader->sizeofbitmap; i++)
      fwrite(buffer, 1, 1, fp);

   fclose(fp);

}  /* ends create_allocate_bmp_file */







      /******************************************
      *
      *   create_bmp_file_if_needed(...
      *
      *   This function allocates a bmp image
      *   file it it does not exist.  It uses
      *   the header information from the input
      *   image name.
      *
      ******************************************/

create_bmp_file_if_needed(in_name, out_name, out_image)
   char in_name[], out_name[];
   short **out_image;
{
   int    length, width;
   struct bmpfileheader file_header;
   struct bitmapheader  bmheader;

   if(does_not_exist(out_name)){
      printf("\n\n output file does not exist %s",
               out_name);
      read_bm_header(in_name, &bmheader);
      create_allocate_bmp_file(out_name, &file_header, &bmheader);
      printf("\nBFIN> Created %s", out_name);
   }  /* ends if does_not_exist */
}  /* ends bmp_file_if_needed */





      /******************************************
      *
      *   write_bmp_image(...
      *
      *   This function writes an image array
      *   to a bmp image file.
      *
      ******************************************/

write_bmp_image(file_name, array)
   char   *file_name;
   short  **array;
{
   char   *buffer, c;
   FILE   *image_file;
   int    pad = 0,
          position;
   int    bytes, i, j;
   long   height = 0, width = 0;
   struct bitmapheader  bmheader;
   struct bmpfileheader file_header;
   struct ctstruct rgb[GRAY_LEVELS+1];
   union  short_char_union scu;

   read_bmp_file_header(file_name, &file_header);
   read_bm_header(file_name, &bmheader);

   height = bmheader.height;
   width  = bmheader.width;
   if(height < 0) height = height*(-1);

   buffer = (char  *) malloc(width * sizeof(char ));
   for(i=0; i<width; i++)
      buffer[i] = '\0';

   image_file = fopen(file_name, "rb+");

      /****************************************
      *
      *   Write the color table first.
      *
      ****************************************/

   position   = fseek(image_file, 54, SEEK_SET);
   for(i=0; i<GRAY_LEVELS+1; i++){
      rgb[i].blue  = i;
      rgb[i].green = i;
      rgb[i].red   = i;
   }  /* ends loop over i */

   for(i=0; i<bmheader.colorsused; i++){
      buffer[0] = rgb[i].blue;
      fwrite(buffer , 1, 1, image_file);
      buffer[0] = rgb[i].green;
      fwrite(buffer , 1, 1, image_file);
      buffer[0] = rgb[i].red;
      fwrite(buffer , 1, 1, image_file);
      buffer[0] = 0x00;
      fwrite(buffer , 1, 1, image_file);
   }  /* ends loop over i */

   position   = fseek(image_file,
                      file_header.bitmapoffset, 
                      SEEK_SET);

   pad = calculate_pad(width);

   for(i=0; i<height; i++){
      for(j=0; j<width; j++){

         if(bmheader.bitsperpixel == 8){
            scu.s_num = 0;
            if(bmheader.height > 0)
               scu.s_num = array[height-1-i][j];
            else
               scu.s_num = array[i][j];
            buffer[j] = scu.s_alpha[0];
         }  /* ends if bits_per_pixel == 8 */
         else{
            printf("\nERROR bitsperpixel is not 8");
            exit(1);
         }
      }  /* ends loop over j */

      bytes = fwrite(buffer, 1, width, image_file);

      if(pad != 0){
         for(j=0; j<pad; j++)
            buffer[j] = 0x00;
         fwrite(buffer, 1, pad, image_file);
      }  /* ends if pad != 0 */

   }  /* ends loop over i */

   fclose(image_file);
   free(buffer);
}  /* ends write_bmp_image */





      /******************************************
      *
      *   calculate_pad(...
      *
      *   This function calculates the pad needed
      *   at the end of each row of pixels in a
      *   bmp image.
      *
      ******************************************/

int calculate_pad(width)
   long width;
{
   int pad = 0;
   pad = ( (width%4) == 0) ? 0 : (4-(width%4));
   return(pad);
}  /* ends calculate_pad */



   /**********************************************
   *
   *   get_image_size(...
   *
   *   This function reads the rows and cols
   *   from the header of either a tif or bmp
   *   image file.
   *
   *   IF IT CANNOT FIND THIS INFORMATION,
   *   it returns a ZERO.
   *
   ***********************************************/

int get_image_size(file_name, rows, cols)
   char *file_name;
   long *cols, *rows;
{
   int is_bmp  = 0,
       is_tiff = 0,
       result  = 0;
   struct bitmapheader bmph;
   struct tiff_header_struct tiffh;

   if(is_a_bmp(file_name)){
      is_bmp = 1;
      read_bm_header(file_name, &bmph);
      *rows = bmph.height;
      *cols = bmph.width;
   }  /* ends if is_a_bmp */

   if(is_a_tiff(file_name)){
      is_tiff = 1;
      read_tiff_header(file_name, &tiffh);
      *rows = tiffh.image_length;
      *cols = tiffh.image_width;
   }  /* ends if is_a_bmp */

   if(is_bmp == 1  ||  is_tiff == 1)
      result = 1;

   return(result);
}  /* ends get_image_size */






      /******************************************
      *
      *   get_bitsperpixel(...
      *
      *   This function reads the bits per pixel
      *   from either a tif or bmp image file.
      *
      ******************************************/

int get_bitsperpixel(file_name, bitsperpixel)
   char *file_name;
   long *bitsperpixel;
{
   int    is_bmp  = 0,
          is_tiff = 0,
          result  = 0;
   long   temp;
   struct bitmapheader bmph;
   struct tiff_header_struct tiffh;

   if(is_a_bmp(file_name)){
      is_bmp = 1;
      read_bm_header(file_name, &bmph);
      temp = (long)bmph.bitsperpixel;
      *bitsperpixel = temp;
   }  /* ends if is_a_bmp */

   if(is_a_tiff(file_name)){
      is_tiff = 1;
      read_tiff_header(file_name, &tiffh);
      *bitsperpixel = tiffh.bits_per_pixel;
   }  /* ends if is_a_bmp */

   if(is_bmp == 1  ||  is_tiff == 1)
      result = 1;

   return(result);
}  /* ends get_image_size */



   /**********************************************
   *
   *   is_a_bmp(...
   *
   *   This function looks at a file to see if it
   *   is a bmp file.  First look at the file
   *   extension.  Next look at the filetype to
   *   ensure it is 0x4d42.
   *
   ***********************************************/

int is_a_bmp(file_name)
   char *file_name;
{
   char   *cc;
   int    result = 0;
   struct bmpfileheader file_header;

   cc = strstr(file_name, ".bmp");
   if(cc == NULL)
      return(result);

   read_bmp_file_header(file_name, &file_header);
   if(file_header.filetype != 0x4d42)
      return(result);

   result = 1;
   return(result);
}  /* ends is_a_bmp */





   /**********************************************
   *
   *   is_a_tiff(...
   *
   *   This function looks at a file to see if it
   *   is a tiff file.  First look at the file
   *   extension.  Next look at the first four 
   *   bytes of the header.
   *
   ***********************************************/


int is_a_tiff(file_name)
   char *file_name;
{
   char   *cc;
   char   buffer[4];
   FILE   *fp;
   int    ok     = 0,
          result = 0;

   cc = strstr(file_name, ".tif");
   if(cc == NULL)
      return(result);

   fp = fopen(file_name, "rb");
   fread(buffer, 1, 4, fp);
   fclose(fp);

   if(buffer[0] == 0x49  &&
      buffer[1] == 0x49  &&
      buffer[2] == 0x2a  &&
      buffer[3] == 0x00)
      ok = 1;

   if(buffer[0] == 0x4d  &&
      buffer[1] == 0x4d  &&
      buffer[2] == 0x00  &&
      buffer[3] == 0x2a)
      ok = 1;

   if(ok == 0)
      return(result);

   result = 1;
   return(result);
}  /* ends is_a_tiff */




   /*******************************************
   *
   *   read_image_array(...
   *
   *   This routine reads the image data from
   *   either a tiff or bmp image.
   *
   ********************************************/

read_image_array(file_name, array)
   char  *file_name;
   short **array;
{
   int ok = 0;

   if(is_a_tiff(file_name)){
      read_tiff_image(file_name, array);
      ok = 1;
   }
   
   if(is_a_bmp(file_name)){
      read_bmp_image(file_name, array);
      ok = 1;
   }

   if(ok == 0){
      printf("\nERROR could not read file %s",
             file_name);
      exit(1);
   }

}  /* ends read_image_array */







   /*******************************************
   *
   *   write_image_array(...
   *
   *   This routine writes the image data to
   *   either a tiff or bmp image.
   *
   ********************************************/

write_image_array(file_name, array)
   char  *file_name;
   short **array;
{
   int ok = 0;

   if(is_a_tiff(file_name)){
      write_tiff_image(file_name, array);
      ok = 1;
   }
   
   if(is_a_bmp(file_name)){
      write_bmp_image(file_name, array);
      ok = 1;
   }

   if(ok == 0){
      printf("\nERROR could not write file %s",
             file_name);
      exit(1);
   }

}  /* ends write_image_array */



   /*********************************************
   *
   *   equate_tiff_headers(...
   *
   *   This function sets the elements of the
   *   destination header to the values of the
   *   source header.
   *
   *********************************************/

equate_tiff_headers(src, dest)
   struct tiff_header_struct *src, *dest;
{
   dest->lsb            = src->lsb;
   dest->bits_per_pixel = src->bits_per_pixel;
   dest->image_length   = src->image_length;
   dest->image_width    = src->image_width;
   dest->strip_offset   = src->strip_offset;
}  /* ends equate_tiff_headers */




   /*********************************************
   *
   *   equate_bmpfileheaders(...
   *
   *   This function sets the elements of the
   *   destination header to the values of the
   *   source header.
   *
   *********************************************/

equate_bmpfileheaders(src, dest)
   struct bmpfileheader *src, *dest;
{
   dest->filetype     = src->filetype;
   dest->filesize     = src->filesize;
   dest->reserved1    = src->reserved1;
   dest->reserved2    = src->reserved2;
   dest->bitmapoffset = src->bitmapoffset;
}  /* ends equate_bmpfileheaders */



   /*********************************************
   *
   *   equate_bitmapheaders(...
   *
   *   This function sets the elements of the
   *   destination header to the values of the
   *   source header.
   *
   *********************************************/

equate_bitmapheaders(src, dest)
   struct bitmapheader *src, *dest;
{
   dest->size         = src->size;
   dest->width        = src->width;
   dest->height       = src->width;
   dest->planes       = src->planes;
   dest->bitsperpixel = src->bitsperpixel;
   dest->compression  = src->compression;
   dest->sizeofbitmap = src->sizeofbitmap;
   dest->horzres      = src->horzres;
   dest->vertres      = src->vertres;
   dest->colorsused   = src->colorsused;
   dest->colorsimp    = src->colorsimp;
}  /* ends equate_bitmapheader */