php 将bmp图片转为jpg等其他任意格式的图片

代码如下：

<? php 
// 例子： 
$path = ROOT . ' upload/2009/06/03/124401282315771. ' ; 
$pathAll = $path . ' bmp ' ; 
$mi = '' ; 
$mi = ImageCreateFromBMP( $pathAll ); 
imagejpeg( $mi , $path . ' jpg ' ); 
// 函数如下： 
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 ; 
} 
?>