一个从图片文件中返回图片尺寸和类型的class

    <?

class ImgSize {

var $VERSION = "1.03b";
var $PHP405 = FALSE;
var $ISTEMPFILE = FALSE;
var $ISURL = FALSE;
var $ERROR = "";

var $BUFSIZE = 1024;
var $TEMPDIR = "/tmp";

var $width = -1;
var $height = -1;
var $type = "";
var $channels = -1;
var $depth = -1;
var $mode = "";

var $types = array(
'^\x0A[\x00,\x02,\x03,\x05]' => "PCX",
'^II\x2a\x00' => "TIF",
'^MM\x00\x2a' => "TIF",
'\#define\s+\S+\s+\d+' => "XBM",
'\/\* XPM \*\/' => "XPM",
'^8BPS' => "PSD",
"^P[1-6]" => "PPM",
'^BM' => "BMP"
);

var $PHPTYPES = array("","GIF","JPG","PNG","SWF");

function imgsize ($f) {

$this->checkphpversion();

if (empty($f)) {
$this->ERROR = "No Image Specified";
return FALSE;
}

if (strtolower(substr($f,0,7)) == 'http://&#39; || strtolower(substr($f,0,6)) == 'ftp://&#39;) {
$this->ISURL = TRUE;

if (!$this->PHP405) {

if (!($f = $this->fetchimage($f))) {
$this->ERROR = "Unable to fetch image";
return FALSE;
}
}
}

if (!$this->ISURL && !is_readable($f)) {
$this->ERROR = "Cannot open image";
return FALSE;
}


if($rt = @GetImageSize($f)) {
$this->width = $rt[0];
$this->height = $rt[1];
$this->type = $this->PHPTYPES[$rt[2]];
if($this->ISTEMPFILE) { unlink ($f); }
return FALSE;
}


$rt = $this->MyGetImageSize($f);
if($this->ISTEMPFILE) { unlink ($f); }
if (!$rt) return FALSE;
return;
}

function MyGetImageSize ($f) {

if (!($fp = @fopen($f,"r"))) {
$this->ERROR = "Cannot open image";
return FALSE;
}


$buf = fread($fp,10);

while (list($a,$b) = each($this->types)) {
if (preg_match("/$a/",$buf)) { $this->type = $b; }
}
if (empty($this->type)) {
$this->type = "Unknown";
$this->ERROR = "Unknown Image Type";
return FALSE;
}

switch ($this->type) {
case "BMP":
fseek($fp,14,SEEK_SET);
$ty = $this->myunpack("V",fread($fp,4));
if ($ty == 40) {
$rt = unpack("Vwidth/Vheight", fread($fp, 8)); // Windows
} else {
$rt = unpack("vwidth/vheight", fread($fp, 4)); // OS/2
}
$this->width = $rt[width]; $this->height = $rt[height];
break;
case "PCX":
fseek($fp,4,SEEK_SET);
$ar = unpack("vxmin/vymin/vxmax/vymax", fread($fp,8));
$this->width = $ar[xmax]-$ar[xmin]+1;
$this->height = $ar[ymax]-$ar[ymin]+1;
break;
case "TIF":
if (preg_match('/MM\x00\x2a/', $buf)) { $en = "n"; } else {$en = "v";}
$enu = strtoupper($en);

$specs = array(0,"C",0,$en,$enu,0,"c",0,$en,$enu);
fseek($fp,4);
$ofs = $this->myunpack($enu, fread($fp,4));
fseek($fp,$ofs);
$de = $this->myunpack($en, fread($fp, 4));
$ofs += 2;
$de = $ofs + ($de * 12);

while (!isset($nx) || !isset($ny)) {
fseek($fp, $ofs);
$ifd = fread($fp, 12);
if (($ifd == "")||($ofs > $de))
break;
$ofs += 12;
$tag = $this->myunpack($en, $ifd);
$type = $this->myunpack($en, substr($ifd, 2, 2));

if (($type > count($specs))) {
continue;
}
if ($tag == 0x0100) {
$x = $this->myunpack($specs[$type], substr($ifd, 8, 4));
} elseif ($tag == 0x0101) {
$y = $this->myunpack($specs[$type], substr($ifd, 8, 4));
}
}
if (isset($x) && isset($y)) {
$this->width = $x;
$this->height = $y;
}
break;
case "PPM":
fseek($fp,0,SEEK_SET);
$hdr = fread($fp, 1024);
preg_match("/^(P[1-7])\s+(\d+)\s+(\d+)/s", $hdr, $r);
$this->width = $r[2];
$this->height = $r[3];
switch($r[1]) {
case "P1":
case "P4":
$this->type = "PBM";
break;
case "P2":
case "P5":
$this->type = "PGM";
break;
case "P3":
case "P6":
$this->type = "PPM";
break;
$this->height = $r[2];
break;
}
break;
case "XBM":
$hdr = fread($fp, 1024);
if (preg_match("/^\#define\s*\S*\s*(\d+)\s*\n\#define\s*\S*\s*(\d+)/si", $hdr, $r)) {
$this->width = $r[1];
$this->height = $r[2];
}
break;
case "XPM":
while ($buf = fread($fp, 1024)) {
if (!preg_match("/\"\s*(\d+)\s+(\d+)(\s+\d+\s+\d+){1,2}\s*\"/s", $buf, $r))
continue;
else {
$this->width = $r[1];
$this->height = $r[2];
break;
}
}
break;
case "PSD":
fseek($fp,12,SEEK_SET);
$ar = unpack("nc/Ny/Nx/nd/nm", fread($fp,14));
$this->channels = $ar[c];
$this->width = $ar[x];
$this->height = $ar[y];
$this->depth = $ar[d];
switch($ar[m]) {
case 0:
$this->mode = "BITMAP";
break;
case 1:
$this->mode = "GRAYSCALE";
break;
case 2:
$this->mode = "INDEXED";
break;
case 3:
$this->mode = "RGB";
break;
case 4:
$this->mode = "CMYK";
break;
case 7:
$this->mode = "MULTICHANNEL";
break;
case 8:
$this->mode = "DUOTONE";
break;
case 9:
$this->mode = "LAB";
break;
}
break;
}
fclose($fp);
}


function myunpack($t,$s) {
$x = unpack($t."x",$s);
return $x[x];
}

function checkphpversion() {
$v = phpversion();


if ($a = strchr($v,'-')) $v = substr($v,0,strlen($v)-strlen($a));


$v = explode('.',$v);
if ($v[0] >= 4 && $v[1] >= 0 && $v[2] >= 5)
$this->PHP405 = TRUE;
else
$this->PHP405 = FALSE;
}

function fetchimage($f) {
if (($fp = @fopen($f,"r")) == FALSE) return FALSE;

$n = tempnam($this->TEMPDIR,"img");
if (($wp = @fopen($n,"w")) == FALSE) {
fclose($fp); return FALSE;
}
while (!feof($fp))
fwrite($wp,fread($fp,$this->BUFSIZE));

fclose($fp);
fclose($wp);
return $n;
}
}
?>