php将bmp格式图片转换成jpg格式程序

时间：2015-01-23 来源：西部数据作者：西部数据

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<strlen($retd);$t+=4)

 {

 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<strlen($data);$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%16);

 }

 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<strlen($data);$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)

{//开源代码phpfensi.com

return chr($n);

};

//实例方法,代码如下:

include_once('bmp.php');

$image=imagecreatefrombmp('a.bmp');

imagejpeg($image,'a.jpeg');

imagedestroy($image);