imagecreatefrombmp.php

<?php
//------------------------------------------------------------------------------
// suporte para a manipulação de arquivos BMP

/*********************************************/
/* Function: ImageCreateFromBMP              */
/* Author:   DHKold                          */
/* Contact:  admin@dhkold.com                */
/* Date:     The 15th of June 2005           */
/* Version:  2.0B                            */
/*********************************************/

function imagecreatefrombmp($filename) {
 //Ouverture du fichier en mode binaire
   if (! $f1 = fopen($filename,"rb")) return FALSE;

 //1 : Chargement des ent?tes FICHIER
   $FILE = unpack("vfile_type/Vfile_size/Vreserved/Vbitmap_offset", fread($f1,14));
   if ($FILE['file_type'] != 19778) return FALSE;

 //2 : Chargement des ent?tes BMP
   $BMP = unpack('Vheader_size/Vwidth/Vheight/vplanes/vbits_per_pixel'.
                     '/Vcompression/Vsize_bitmap/Vhoriz_resolution'.
                     '/Vvert_resolution/Vcolors_used/Vcolors_important', fread($f1,40));
   $BMP['colors'] = pow(2,$BMP['bits_per_pixel']);
   if ($BMP['size_bitmap'] == 0) $BMP['size_bitmap'] = $FILE['file_size'] - $FILE['bitmap_offset'];
   $BMP['bytes_per_pixel'] = $BMP['bits_per_pixel']/8;
   $BMP['bytes_per_pixel2'] = ceil($BMP['bytes_per_pixel']);
   $BMP['decal'] = ($BMP['width']*$BMP['bytes_per_pixel']/4);
   $BMP['decal'] -= floor($BMP['width']*$BMP['bytes_per_pixel']/4);
   $BMP['decal'] = 4-(4*$BMP['decal']);
   if ($BMP['decal'] == 4) $BMP['decal'] = 0;

 //3 : Chargement des couleurs de la palette
   $PALETTE = array();
   if ($BMP['colors'] < 16777216)
   {
     $PALETTE = unpack('V'.$BMP['colors'], fread($f1,$BMP['colors']*4));
   }

 //4 : Cr?ation de l'image
   $IMG = fread($f1,$BMP['size_bitmap']);
   $VIDE = chr(0);

   $res = imagecreatetruecolor($BMP['width'],$BMP['height']);
   $P = 0;
   $Y = $BMP['height']-1;
   while ($Y >= 0)
   {
     $X=0;
     while ($X < $BMP['width'])
     {
      if ($BMP['bits_per_pixel'] == 24)
          $COLOR = @unpack("V",substr($IMG,$P,3).$VIDE);
      elseif ($BMP['bits_per_pixel'] == 16)
      {
          $COLOR = @unpack("n",substr($IMG,$P,2));
          $COLOR[1] = $PALETTE[$COLOR[1]+1];
      }
      elseif ($BMP['bits_per_pixel'] == 8)
      {
          $COLOR = @unpack("n",$VIDE.substr($IMG,$P,1));
          $COLOR[1] = $PALETTE[$COLOR[1]+1];
      }
      elseif ($BMP['bits_per_pixel'] == 4)
      {
          $COLOR = @unpack("n",$VIDE.substr($IMG,floor($P),1));
          if (($P*2)%2 == 0) $COLOR[1] = ($COLOR[1] >> 4) ; else $COLOR[1] = ($COLOR[1] & 0x0F);
          $COLOR[1] = $PALETTE[$COLOR[1]+1];
      }
      elseif ($BMP['bits_per_pixel'] == 1)
      {
          $COLOR = @unpack("n",$VIDE.substr($IMG,floor($P),1));
          if     (($P*8)%8 == 0) $COLOR[1] =  $COLOR[1]          >>7;
          elseif (($P*8)%8 == 1) $COLOR[1] = ($COLOR[1] & 0x40)>>6;
          elseif (($P*8)%8 == 2) $COLOR[1] = ($COLOR[1] & 0x20)>>5;
          elseif (($P*8)%8 == 3) $COLOR[1] = ($COLOR[1] & 0x10)>>4;
          elseif (($P*8)%8 == 4) $COLOR[1] = ($COLOR[1] & 0x8)>>3;
          elseif (($P*8)%8 == 5) $COLOR[1] = ($COLOR[1] & 0x4)>>2;
          elseif (($P*8)%8 == 6) $COLOR[1] = ($COLOR[1] & 0x2)>>1;
          elseif (($P*8)%8 == 7) $COLOR[1] = ($COLOR[1] & 0x1);
          $COLOR[1] = $PALETTE[$COLOR[1]+1];
      }
      else
          return FALSE;
      imagesetpixel($res,$X,$Y,$COLOR[1]);
      $X++;
      $P += $BMP['bytes_per_pixel'];
     }
     $Y--;
     $P+=$BMP['decal'];
   }

 //Fermeture du fichier
   fclose($f1);

 return $res;

} // fim function image from BMP