Conversion de BMP à GIF

BMP to GIF - the C Source Code
Requires Victor Image Processing Library v 5.0 or higher.

int bmp2gif()
{
  imgdes tmpimage;
  int rcode, vbitcount;
  BITMAPINFOHEADER bdat; // Reserve space for BMP struct
  char *src_fname = "test.bmp";
  char far *des_fname = "test.gif";

  // Get info on the file we're to load
  rcode = bmpinfo(src_fname, &bdat);
  if(rcode != NO_ERROR) {
      return(rcode);
      }

  vbitcount = bdat.biBitCount;
  if(vbitcount >= 16)  // 16-, 24-, or 32-bit image is loaded into 24-bit buffer
      vbitcount = 24;

  // Allocate space for an image
  rcode = allocimage(&tmpimage, (int)bdat.biWidth, (int)bdat.biHeight, vbitcount);
  if(rcode != NO_ERROR) {
      return(rcode);
      }

  // Load image
  rcode = loadbmp(src_fname, &tmpimage);
  if(rcode != NO_ERROR) {
      freeimage(&tmpimage); // Release the memory and return if there's an error
      return(rcode);
      }


  // If we loaded a 24-bit image, convert to 8-bit
  // because the GIF format does not support 24-bit images
  if(vbitcount == 24) { 
      imgdes tmp2image;

      rcode = allocimage(&tmp2image, (int)bdat.biWidth, (int)bdat.biHeight, 8);
      if(rcode == NO_ERROR) {
        int colors = 256;
        int reduction_mode = CR_TSDDIFF;  // For the best image quality

        convertrgbtopalex(colors, &tmpimage, &tmp2image, reduction_mode);
        freeimage(&tmpimage);  // Replace 24-bit image with 8-bit image
        copyimgdes(&tmp2image, &tmpimage);
        }
      }

  // Save image
  rcode = savegifex(des_fname, &tmpimage, 8, 0);

  freeimage(&tmpimage);
  return(rcode);
}