本文分析了PHP处理bmp格式图片的方法。分享给大家供大家参考,具体如下:
白天QA提出项目上传图片有问题,具体为:上传成功,预览失败。我去了之后,又上传了几张其他的图片可以上传,然后仔细问了下他上传的是哪张图片,看了后使用getimagesize
函数打印了下。
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Array
(
[0] => 494
[1] => 260
[2] => 6
[3] => width= "494" height= "260"
[bits] => 24
[mime] => image/x-ms-bmp
)
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仔细看下,上面打印的数组,mime为image/x-ms-bmp,也就是bmp格式的,印象中php的gd库没有处理这个函数,后来我便在配置文件中,只要mime为这种的便不能上传。
晚上回来后,我便在网上查找php处理bmp相关方法,后来终于在*中找到了,帖子里说进入官网的有关imagecreate的函数评论,有个ImageCreateFromBMP
方法,先把bmp格式的文件给此函数调用,再用imagejpeg保存就行,后来试了下,发现imagepng也行,下面贴出代码。
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<?php
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 ;
}
$pic = '2.bmp' ;
$res = ImageCreateFromBMP( $pic );
imagepng( $res , '1.png' );
imagejpeg( $res , '1.jpeg' );
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希望本文所述对大家PHP程序设计有所帮助。