/**
*
* @convert BMP to GD
*
* @param string $src
*
* @param string|bool $dest
*
* @return bool
*
*/
function bmp2gd($src, $dest = false)
{
/*** try to open the file for reading ***/
if(!($src_f = fopen($src, "rb")))
{
return false;
}
/*** try to open the destination file for writing ***/
if(!($dest_f = fopen($dest, "wb")))
{
return false;
}
/*** grab the header ***/
$header = unpack("vtype/Vsize/v2reserved/Voffset", fread( $src_f, 14));
/*** grab the rest of the image ***/
$info = unpack("Vsize/Vwidth/Vheight/vplanes/vbits/Vcompression/Vimagesize/Vxres/Vyres/Vncolor/Vimportant",
fread($src_f, 40));
/*** extract the header and info into varibles ***/
extract($info);
extract($header);
/*** check for BMP signature ***/
if($type != 0x4D42)
{
return false;
}
/*** set the pallete ***/
$palette_size = $offset - 54;
$ncolor = $palette_size / 4;
$gd_header = "";
/*** true-color vs. palette ***/
$gd_header .= ($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);
}
/*** we do not allow transparency ***/
$gd_header .= "\xFF\xFF\xFF\xFF";
/*** write the destination headers ***/
fwrite($dest_f, $gd_header);
/*** if we have a valid palette ***/
if($palette_size)
{
/*** read the palette ***/
$palette = fread($src_f, $palette_size);
/*** begin the gd palette ***/
$gd_palette = "";
$j = 0;
/*** loop of the palette ***/
while($j < $palette_size)
{
$b = $palette{$j++};
$g = $palette{$j++};
$r = $palette{$j++};
$a = $palette{$j++};
/*** assemble the gd palette ***/
$gd_palette .= "$r$g$b$a";
}
/*** finish the palette ***/
$gd_palette .= str_repeat("\x00\x00\x00\x00", 256 - $ncolor);
/*** write the gd palette ***/
fwrite($dest_f, $gd_palette);
}
/*** scan line size and alignment ***/
$scan_line_size = (($bits * $width) + 7) >> 3;
$scan_line_align = ($scan_line_size & 0x03) ? 4 - ($scan_line_size & 0x03) : 0;
/*** this is where the work is done ***/
for($i = 0, $l = $height - 1; $i < $height; $i++, $l--)
{
/*** create scan lines starting from bottom ***/
fseek($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";
}
}
elseif($bits == 8)
{
$gd_scan_line = $scan_line;
}
elseif($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, $width);
}
elseif($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";
}
/*** put the gd scan lines together ***/
$gd_scan_line = substr($gd_scan_line, 0, $width);
}
/*** write the gd scan lines ***/
fwrite($dest_f, $gd_scan_line);
}
/*** close the source file ***/
fclose($src_f);
/*** close the destination file ***/
fclose($dest_f);
return true;
}
/**
*
* @ceate a BMP image
*
* @param string $filename
*
* @return bin string on success
*
* @return bool false on failure
*
*/
function ImageCreateFromBmp($filename)
{
/*** create a temp file ***/
$tmp_name = tempnam("/tmp", "GD");
/*** convert to gd ***/
if(bmp2gd($filename, $tmp_name))
{
/*** create new image ***/
$img = imagecreatefromgd($tmp_name);
/*** remove temp file ***/
unlink($tmp_name);
/*** return the image ***/
return $img;
}
return false;
}
/*** example usage ***/
/*** read in the BMP image ***/
$img = ImageCreateFromBmp("1.bmp");
/*** write the new jpeg image ***/
imagejpeg($img, "2.jpg");
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