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 ;
}
?>