php将bmp格式图片转换成jpg格式程序_PHP教程

php将bmp格式图片转换成jpg格式程序_PHP教程,第1张

php教程bmp格式图片转换成jpg格式程序

function imagebmp($img,$file="",$rle=0)
{


$colorcount=imagecolorstotal($img);

$transparent=imagecolortransparent($img);
$istransparent=$transparent!=-1;


if($istransparent) $colorcount--;

if($colorcount==0) {$colorcount=0; $bitcount=24;};
if(($colorcount>0)and($colorcount<=2)) {$colorcount=2; $bitcount=1;};
if(($colorcount>2)and($colorcount<=16)) { $colorcount=16; $bitcount=4;};
if(($colorcount>16)and($colorcount<=256)) { $colorcount=0; $bitcount=8;};


$width=imagesx($img);
$height=imagesy($img);

$zbytek=(4-($width/(8/$bitcount))%4)%4;

if($bitcount<24) $palsize=pow(2,$bitcount)*4;

$size=(floor($width/(8/$bitcount)) $zbytek)*$height 54;
$size =$palsize;
$offset=54 $palsize;

// bitmap file header
$ret = 'bm'; // header (2b)
$ret .= int_to_dword($size); // size of file (4b)
$ret .= int_to_dword(0); // reserved (4b)
$ret .= int_to_dword($offset); // byte location in the file which is first byte of image (4b)
// bitmap info header
$ret .= int_to_dword(40); // size of bitmapinfoheader (4b)
$ret .= int_to_dword($width); // width of bitmap (4b)
$ret .= int_to_dword($height); // height of bitmap (4b)
$ret .= int_to_word(1); // biplanes = 1 (2b)
$ret .= int_to_word($bitcount); // bibitcount = {1 (mono) or 4 (16 clr ) or 8 (256 clr) or 24 (16 mil)} (2b)
$ret .= int_to_dword($rle); // rle compression (4b)
$ret .= int_to_dword(0); // width x height (4b)
$ret .= int_to_dword(0); // bixpelspermeter (4b)
$ret .= int_to_dword(0); // biypelspermeter (4b)
$ret .= int_to_dword(0); // number of palettes used (4b)
$ret .= int_to_dword(0); // number of important colour (4b)
// image data

$cc=$colorcount;
$sl1=strlen($ret);
if($cc==0) $cc=256;
if($bitcount<24)
{
$colortotal=imagecolorstotal($img);
if($istransparent) $colortotal--;

for($p=0;$p<$colortotal;$p )
{
$color=imagecolorsforindex($img,$p);
$ret.=inttobyte($color["blue"]);
$ret.=inttobyte($color["green"]);
$ret.=inttobyte($color["red"]);
$ret.=inttobyte(0); //reserved
};

$ct=$colortotal;
for($p=$colortotal;$p<$cc;$p )
{
$ret.=inttobyte(0);
$ret.=inttobyte(0);
$ret.=inttobyte(0);
$ret.=inttobyte(0); //reserved
};
};


if($bitcount<=8)
{

for($y=$height-1;$y>=0;$y--)
{
$bwrite="";
for($x=0;$x<$width;$x )
{
$color=imagecolorat($img,$x,$y);
$bwrite.=decbinx($color,$bitcount);
if(strlen($bwrite)==8)
{
$retd.=inttobyte(bindec($bwrite));
$bwrite="";
};
};

if((strlen($bwrite)<8)and(strlen($bwrite)!=0))
{
$sl=strlen($bwrite);
for($t=0;$t<8-$sl;$t )
$sl.="0";
$retd.=inttobyte(bindec($bwrite));
};
for($z=0;$z<$zbytek;$z )
$retd.=inttobyte(0);
};
};

if(($rle==1)and($bitcount==8))
{
for($t=0;$t {
if($t!=0)
if(($t)%$width==0)
$ret.=chr(0).chr(0);

if(($t 5)%$width==0)
{
$ret.=chr(0).chr(5).substr($retd,$t,5).chr(0);
$t =1;
}
if(($t 6)%$width==0)
{
$ret.=chr(0).chr(6).substr($retd,$t,6);
$t =2;
}
else
{
$ret.=chr(0).chr(4).substr($retd,$t,4);
};
};
$ret.=chr(0).chr(1);
}
else
{
$ret.=$retd;
};


if($bitcount==24)
{
for($z=0;$z<$zbytek;$z )
$dopl.=chr(0);

for($y=$height-1;$y>=0;$y--)
{
for($x=0;$x<$width;$x )
{
$color=imagecolorsforindex($img,imagecolorat($img,$x,$y));
$ret.=chr($color["blue"]).chr($color["green"]).chr($color["red"]);
}
$ret.=$dopl;
};

};

if($file!="")
{
$r=($f=fopen($file,"w"));
$r=$r and fwrite($f,$ret);
$r=$r and fclose($f);
return $r;
}
else
{
echo $ret;
};
};


/*
*------------------------------------------------------------
* imagecreatefrombmp
*------------------------------------------------------------
* - reads image from a bmp file
*
* parameters: $file - target file to load
*
* returns: image id
*/

function imagecreatefrombmp($file)
{
global $currentbit, $echomode;

$f=fopen($file,"r");
$header=fread($f,2);

if($header=="bm")
{
$size=freaddword($f);
$reserved1=freadword($f);
$reserved2=freadword($f);
$firstbyteofimage=freaddword($f);

$sizebitmapinfoheader=freaddword($f);
$width=freaddword($f);
$height=freaddword($f);
$biplanes=freadword($f);
$bibitcount=freadword($f);
$rlecompression=freaddword($f);
$widthxheight=freaddword($f);
$bixpelspermeter=freaddword($f);
$biypelspermeter=freaddword($f);
$numberofpalettesused=freaddword($f);
$numberofimportantcolors=freaddword($f);

if($bibitcount<24)
{
$img=imagecreate($width,$height);
$colors=pow(2,$bibitcount);
for($p=0;$p<$colors;$p )
{
$b=freadbyte($f);
$g=freadbyte($f);
$r=freadbyte($f);
$reserved=freadbyte($f);
$palette[]=imagecolorallocate($img,$r,$g,$b);
};


if($rlecompression==0)
{
$zbytek=(4-ceil(($width/(8/$bibitcount)))%4)%4;

for($y=$height-1;$y>=0;$y--)
{
$currentbit=0;
for($x=0;$x<$width;$x )
{
$c=freadbits($f,$bibitcount);
imagesetpixel($img,$x,$y,$palette[$c]);
};
if($currentbit!=0) {freadbyte($f);};
for($g=0;$g<$zbytek;$g )
freadbyte($f);
};

};
};


if($rlecompression==1) //$bi_rle8
{
$y=$height;

$pocetb=0;

while(true)
{
$y--;
$prefix=freadbyte($f);
$suffix=freadbyte($f);
$pocetb =2;

$echoit=false;

if($echoit)echo "prefix: $prefix suffix: $suffix
";
if(($prefix==0)and($suffix==1)) break;
if(feof($f)) break;

while(!(($prefix==0)and($suffix==0)))
{
if($prefix==0)
{
$pocet=$suffix;
$data.=fread($f,$pocet);
$pocetb =$pocet;
if($pocetb%2==1) {freadbyte($f); $pocetb ;};
};
if($prefix>0)
{
$pocet=$prefix;
for($r=0;$r<$pocet;$r )
$data.=chr($suffix);
};
$prefix=freadbyte($f);
$suffix=freadbyte($f);
$pocetb =2;
if($echoit) echo "prefix: $prefix suffix: $suffix
";
};

for($x=0;$x {
imagesetpixel($img,$x,$y,$palette[ord($data[$x])]);
};
$data="";

};

};


if($rlecompression==2) //$bi_rle4
{
$y=$height;
$pocetb=0;

/*while(!feof($f))
echo freadbyte($f)."_".freadbyte($f)."
";*/
while(true)
{
//break;
$y--;
$prefix=freadbyte($f);
$suffix=freadbyte($f);
$pocetb =2;

$echoit=false;

if($echoit)echo "prefix: $prefix suffix: $suffix
";
if(($prefix==0)and($suffix==1)) break;
if(feof($f)) break;

while(!(($prefix==0)and($suffix==0)))
{
if($prefix==0)
{
$pocet=$suffix;

$currentbit=0;
for($h=0;$h<$pocet;$h )
$data.=chr(freadbits($f,4));
if($currentbit!=0) freadbits($f,4);
$pocetb =ceil(($pocet/2));
if($pocetb%2==1) {freadbyte($f); $pocetb ;};
};
if($prefix>0)
{
$pocet=$prefix;
$i=0;
for($r=0;$r<$pocet;$r )
{
if($i%2==0)
{
$data.=chr($suffix);
}
else
{
$data.=chr(floor($suffix/16));
};
$i ;
};
};
$prefix=freadbyte($f);
$suffix=freadbyte($f);
$pocetb =2;
if($echoit) echo "prefix: $prefix suffix: $suffix
";
};

for($x=0;$x {
imagesetpixel($img,$x,$y,$palette[ord($data[$x])]);
};
$data="";

};

};


if($bibitcount==24)
{
$img=imagecreatetruecolor($width,$height);
$zbytek=$width%4;

for($y=$height-1;$y>=0;$y--)
{
for($x=0;$x<$width;$x )
{
$b=freadbyte($f);
$g=freadbyte($f);
$r=freadbyte($f);
$color=imagecolorexact($img,$r,$g,$b);
if($color==-1) $color=imagecolorallocate($img,$r,$g,$b);
imagesetpixel($img,$x,$y,$color);
}
for($z=0;$z<$zbytek;$z )
freadbyte($f);
};
};
return $img;

};


fclose($f);


};

/*
* helping functions:
*-------------------------
*
* freadbyte($file) - reads 1 byte from $file
* freadword($file) - reads 2 bytes (1 word) from $file
* freaddword($file) - reads 4 bytes (1 dword) from $file
* freadlngint($file) - same as freaddword($file)
* decbin8($d) - returns binary string of d zero filled to 8
* retbits($byte,$start,$len) - returns bits $start->$start $len from $byte
* freadbits($file,$count) - reads next $count bits from $file
* rgbtohex($r,$g,$b) - convert $r, $g, $b to hex
* int_to_dword($n) - returns 4 byte representation of $n
* int_to_word($n) - returns 2 byte representation of $n
*/

function freadbyte($f)
{
return ord(fread($f,1));
};

function freadword($f)
{
$b1=freadbyte($f);
$b2=freadbyte($f);
return $b2*256 $b1;
};


function freadlngint($f)
{
return freaddword($f);
};

function freaddword($f)
{
$b1=freadword($f);
$b2=freadword($f);
return $b2*65536 $b1;
};

function retbits($byte,$start,$len)
{
$bin=decbin8($byte);
$r=bindec(substr($bin,$start,$len));
return $r;

};

$currentbit=0;
function freadbits($f,$count)
{
global $currentbit,$smode;
$byte=freadbyte($f);
$lastcbit=$currentbit;
$currentbit =$count;
if($currentbit==8)
{
$currentbit=0;
}
else
{
fseek($f,ftell($f)-1);
};
return retbits($byte,$lastcbit,$count);
};

function rgbtohex($red,$green,$blue)
{
$hred=dechex($red);if(strlen($hred)==1) $hred="0$hred";
$hgreen=dechex($green);if(strlen($hgreen)==1) $hgreen="0$hgreen";
$hblue=dechex($blue);if(strlen($hblue)==1) $hblue="0$hblue";
return($hred.$hgreen.$hblue);
};

function int_to_dword($n)
{
return chr($n & 255).chr(($n >> 8) & 255).chr(($n >> 16) & 255).chr(($n >> 24) & 255);
}
function int_to_word($n)
{
return chr($n & 255).chr(($n >> 8) & 255);
}


function decbin8($d)
{
return decbinx($d,8);
};

function decbinx($d,$n)
{
$bin=decbin($d);
$sbin=strlen($bin);
for($j=0;$j<$n-$sbin;$j )
$bin="0$bin";
return $bin;
};

function inttobyte($n)
{
return chr($n);
};

//实例方法

include_once('bmp.php');
$image=imagecreatefrombmp('a.bmp');
imagejpeg($image,'a.jpeg');
imagedestroy($image);


www.bkjia.comtruehttp://www.bkjia.com/PHPjc/444910.htmlTechArticlephp教程将bmp格式图片转换成jpg格式程序 function imagebmp($img,$file=,$rle=0) { $colorcount=imagecolorstotal($img); $transparent=imagecolortransparent($img); $istranspa...

文章来源:https://www.php.cn/faq/305623.html

本文经用户投稿或网站收集转载,如有侵权请联系本站。

发表评论

0条回复

    作者信息

    相关文章