php将bmp格式图片转换成jpg格式程序-php教程

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);

php将bmp格式图片转换成jpg格式程序

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