php 水印生成图片压缩

<?php
class Image
{
/**
*  质量大小
*/
public  $size = 70;

/**
*  图片加水印
*/
function imageMark($srcImg, $waterImg, $savepath=null, $savename=null, $positon=5, $alpha=100)
{
$temp = pathinfo($srcImg);
$name = $temp['basename'];
$path = $temp['dirname'];
$exte = $temp['extension'];
$savename = $savename ? $savename : $name;
$savepath = $savepath ? $savepath : $path;
$savefile = $savepath .'/'. $savename;
$srcinfo = @getimagesize($srcImg);

if (!$srcinfo) {
throw new Exception("原文件不存在!");
}
$waterinfo = @getimagesize($waterImg);

if (!$waterinfo)
{
throw new Exception("水印图片不存在!");
}
$srcImgObj = $this->image_create_from_ext($srcImg);
if (!$srcImgObj) {
return -3;  //原文件图像对象建立失败
}
$waterImgObj = $this->image_create_from_ext($waterImg);
if (!$waterImgObj)
{
throw new Exception("水印文件图像对象建立失败!");
}
switch ($positon) {
//1顶部居左
case 1: $x=$y=0; break;
//2顶部居右
case 2: $x = $srcinfo[0]-$waterinfo[0]; $y = 0; break;
//3居中
case 3: $x = ($srcinfo[0]-$waterinfo[0])/2; $y = ($srcinfo[1]-$waterinfo[1])/2; break;
//4底部居左
case 4: $x = 0; $y = $srcinfo[1]-$waterinfo[1]; break;
//5底部居右
case 5: $x = $srcinfo[0]-$waterinfo[0]; $y = $srcinfo[1]-$waterinfo[1]; break;
default: $x=$y=0;
}
imagecopymerge($srcImgObj, $waterImgObj, $x, $y, 0, 0, $waterinfo[0], $waterinfo[1], $alpha);
switch ($srcinfo[2])
{
case 1: imagegif($srcImgObj, $savefile); break;
case 2: imagejpeg($srcImgObj, $savefile); break;
case 3: imagepng($srcImgObj, $savefile); break;
default:throw new Exception("保存失败!"); break;
}
imagedestroy($srcImgObj);
imagedestroy($waterImgObj);
return $savefile;
}

function image_create_from_ext( $imgfile )
{
$info = getimagesize( $imgfile );
$im = null;
switch ($info[2])
{
case 1: $im=imagecreatefromgif( $imgfile ); break;
case 2: $im=imagecreatefromjpeg( $imgfile ); break;
case 3: $im=imagecreatefrompng( $imgfile ); break;
default:throw new Exception("保存失败!"); break;
}
return $im;
}

/**
*  $imgsrc 图片路径
*  $imgdst 生成后的路径
*  生成缩略图
*/
function thumb($imgsrc,$w=null,$h=null,$imgdst=null)
{
$imgdst = $imgdst?$imgdst:$imgsrc;
//给变量赋值
list($width,$height,$type) = getimagesize($imgsrc);
$new_width =  $width>$w?$w:$width;
$new_height = $height>$h?$h:$height;
switch($type)
{
case 1:
$giftype=check_gifcartoon($imgsrc);
if($giftype){
header('Content-Type:image/gif');
$image_wp=imagecreatetruecolor($new_width, $new_height);
$image = imagecreatefromgif($imgsrc);
imagecopyresampled($image_wp, $image, 0, 0, 0, 0, $new_width, $new_height, $width, $height);
imagejpeg($image_wp, $imgdst,$this->size);
imagedestroy($image_wp);
}
break;
case 2:
header('Content-Type:image/jpeg');
$image_wp=imagecreatetruecolor($new_width, $new_height);
$image = imagecreatefromjpeg($imgsrc);
imagecopyresampled($image_wp, $image, 0, 0, 0, 0, $new_width, $new_height, $width, $height);
imagejpeg($image_wp, $imgdst,$this->size);
imagedestroy($image_wp);
break;
case 3:
header('Content-Type:image/png');
$image_wp=imagecreatetruecolor($new_width, $new_height);
$image = imagecreatefrompng($imgsrc);
imagecopyresampled($image_wp, $image, 0, 0, 0, 0, $new_width, $new_height, $width, $height);
imagejpeg($image_wp, $imgdst,$this->size);
imagedestroy($image_wp);
break;
default:
throw new Exception("保存失败!");
break;
}
}

function check_gifcartoon($image_file)
{
$fp = fopen($image_file,'rb');
$image_head = fread($fp,1024);
fclose($fp);
return preg_match("/".chr(0x21).chr(0xff).chr(0x0b).'NETSCAPE2.0'."/",$image_head)?false:true;
}

}