Konverter bmp og gif til jpg

Noget i den stil..

<?php
  $Source = "filename.(gif, jpg, png, bmp, wbmp, xbm)"
  $hImg = ImageCreateFromFile($Source);
  ImageJPEG($hImg, "filename.jpg", 85);
  ImageDestroy($hImg);

    function ImageCreateFromFile($strFilename) {
        if (file_exists($strFilename)) {
            list($nWidth, $nHeight, $nType) = @GetImageSize($strFilename);
            switch($nType) {
                    case 1:  $hImg = ImageCreateFromGIF ($strFilename); break;
                    case 2:  $hImg = ImageCreateFromJPEG($strFilename); break;
                    case 3:  $hImg = ImageCreateFromPNG ($strFilename); break;
                    case 6:  $hImg = ImageCreateFromBMP ($strFilename); break;
                    case 15: $hImg = ImageCreateFromWBMP($strFilename); break;
                    case 16: $hImg = ImageCreateFromXBM ($strFilename); break;
                    default: $hImg = 0; break;
            }
            return $hImg;
        }
    }

  // Function for ImageCreateFromBMP()
  function ImageCreateFromBMP($filename) {
    if(!($src_f = fopen($filename, "rb"))) {
      return false;
    }

        $tmp_name = tempnam("/tmp", "GD");
    if(!($dest_f = fopen($tmp_name, "wb"))) {
      return false;
    }

    $header = unpack("vtype/Vsize/v2reserved/Voffset", fread($src_f, 14));
    $info = unpack("Vsize/Vwidth/Vheight/vplanes/vbits/Vcompression/".
        "Vimagesize/Vxres/Vyres/Vncolor/Vimportant", fread($src_f, 40));
 
    extract($info);
    extract($header);
 
    if($type != 0x4D42) {
      return false;
    }
 
    $palette_size = $offset - 54;
    $ncolor = $palette_size / 4;
    $gd_header = "";
 
    $gd_header .= ($palette_size == 0) ? "\xFF\xFE" : "\xFF\xFF";
    $gd_header .= pack("n2", $width, $height);
    $gd_header .= ($palette_size == 0) ? "\x01" : "\x00";
 
    if($palette_size) {
      $gd_header .= pack("n", $ncolor);
    }
 
    $gd_header .= "\xFF\xFF\xFF\xFF";
 
    fwrite($dest_f, $gd_header);
 
    if($palette_size) {
      $palette = fread($src_f, $palette_size);
      $gd_palette = "";
      $j = 0;
 
      while($j < $palette_size) {
        $b = $palette{$j++};
        $g = $palette{$j++};
        $r = $palette{$j++};
        $a = $palette{$j++};
        $gd_palette .= "$r$g$b$a";
      }
 
      $gd_palette .= str_repeat("\x00\x00\x00\x00", 256 - $ncolor);
      fwrite($dest_f, $gd_palette);
    }
 
    $scan_line_size = (($bits * $width) + 7) >> 3;
    $scan_line_align = ($scan_line_size & 0x03) ? 4 - ($scan_line_size & 0x03) : 0;
 
    for($i = 0, $l = $height - 1; $i < $height; $i++, $l--) {
      fseek($src_f, $offset + (($scan_line_size + $scan_line_align) * $l));
      $scan_line = fread($src_f, $scan_line_size);
      if($bits == 24) {
        $gd_scan_line = "";
        $j = 0;
        while($j < $scan_line_size) {
          $b = $scan_line{$j++};
          $g = $scan_line{$j++};
          $r = $scan_line{$j++};
          $gd_scan_line .= "\x00$r$g$b";
        }
      }
      else if($bits == 8) {
        $gd_scan_line = $scan_line;
      }
      else if($bits == 4) {
      $gd_scan_line = "";
      $j = 0;
      while($j < $scan_line_size) {
        $byte = ord($scan_line{$j++});
        $p1 = chr($byte >> 4);
        $p2 = chr($byte & 0x0F);
        $gd_scan_line .= "$p1$p2";
      }
      $gd_scan_line = substr($gd_scan_line, 0, $width);
      }
      else if($bits == 1) {
        $gd_scan_line = "";
        $j = 0;
        while($j < $scan_line_size) {
          $byte = ord($scan_line{$j++});
          $p1 = chr((int) (($byte & 0x80) != 0));
          $p2 = chr((int) (($byte & 0x40) != 0));
          $p3 = chr((int) (($byte & 0x20) != 0));
          $p4 = chr((int) (($byte & 0x10) != 0));
          $p5 = chr((int) (($byte & 0x08) != 0));
          $p6 = chr((int) (($byte & 0x04) != 0));
          $p7 = chr((int) (($byte & 0x02) != 0));
          $p8 = chr((int) (($byte & 0x01) != 0));
          $gd_scan_line .= "$p1$p2$p3$p4$p5$p6$p7$p8";
        }
      $gd_scan_line = substr($gd_scan_line, 0, $width);
    }
    fwrite($dest_f, $gd_scan_line);
    }

    fclose($src_f);
    fclose($dest_f);

        $hImg = ImageCreateFromGD($tmp_name);
        unlink($tmp_name);

    return $hImg;
  }
?>