php图片水印类详解编程语言

<?php 
class Image { 
private $path; 
//构造方法用来对图片所在位置进行初使化 
function __construct($path="./"){ 
$this->path=rtrim($path, "/")."/"; 
$this -> path = ''; 
} 
/* 对图片进行缩放 
* 
* 参数$name: 是需要处理的图片名称 
* 参数$width:是缩放后的宽度 
* 参数$height:是缩放后的高度 
* 参数$qz: 是新图片的名称前缀 
* 返回值:就是缩放后的图片名称，失败则返回false 
* 
*/ 
function thumb($name, $width, $height, $qz="th_"){ 
//获取图片信息 
$imgInfo=$this->getInfo($name); //图片的宽度，高度，类型 
//获取图片资源, 各种类型的图片都可以创建资源 jpg, gif, png 
$srcImg=$this->getImg($name, $imgInfo); 
//获取计算图片等比例之后的大小, $size["width"], $size["height"] 
$size=$this->getNewSize($name, $width, $height, $imgInfo); 
//获取新的图片资源, 处理一下gif透明背景 
$newImg=$this->kidOfImage($srcImg, $size, $imgInfo); 
//另存为一个新的图片，返回新的缩放后的图片名称     
return $this->createNewImage($newImg, $qz.$name, $imgInfo);     
} 
private function createNewImage($newImg, $newName, $imgInfo){ 
switch($imgInfo["type"]){ 
case 1://gif 
Header("Content-type: image/gif"); 
$result=imageGif($newImg); 
break; 
case 2://jpg 
Header("Content-type: image/jpg"); 
$result=imageJPEG($newImg); 
break; 
case 3://png 
Header("Content-type: image/png"); 
$return=imagepng($newImg); 
break; 
} 
imagedestroy($newImg); 
return $newName; 
} 
private function kidOfImage($srcImg, $size, $imgInfo){ 
$newImg=imagecreatetruecolor($size["width"], $size["height"]); 
$otsc=imagecolortransparent($srcImg); 
if($otsc >=0 && $otsc <= imagecolorstotal($srcImg)){ 
$tran=imagecolorsforindex($srcImg, $otsc); 
$newt=imagecolorallocate($newImg, $tran["red"], $tran["green"], $tran["blue"]); 
imagefill($newImg, 0, 0, $newt); 
imagecolortransparent($newImg, $newt); 
} 
imagecopyresized($newImg, $srcImg, 0, 0, 0, 0, $size["width"], $size["height"], $imgInfo["width"], $imgInfo["height"]); 
imagedestroy($srcImg); 
return $newImg; 
} 
private function getNewSize($name, $width, $height, $imgInfo){ 
$size["width"]=$imgInfo["width"]; 
$size["height"]=$imgInfo["height"]; 
//缩放的宽度如果比原图小才重新设置宽度 
if($width < $imgInfo["width"]){ 
$size["width"]=$width; 
} 
//缩放的高度如果比原图小才重新设置高度 
if($height < $imgInfo["height"]){ 
$size["height"]=$height; 
} 
//图片等比例缩放的算法 
if($imgInfo["width"]*$size["width"] > $imgInfo["height"] * $size["height"]){ 
$size["height"]=round($imgInfo["height"]*$size["width"]/$imgInfo["width"]); 
}else{ 
$size["width"]=round($imgInfo["width"]*$size["height"]/$imgInfo["height"]); 
} 
return $size; 
} 
public function getInfo($name){ 
$data=getImageSize($this->path.$name); 
$imageInfo["width"]=$data[0]; 
$imageInfo["height"]=$data[1]; 
$imageInfo["type"]=$data[2]; 
return $imageInfo; 
} 
private function getImg($name, $imgInfo){ 
$srcPic=$this->path.$name; 
switch($imgInfo["type"]){ 
case 1: //gif 
$img=imagecreatefromgif($srcPic); 
break; 
case 2: //jpg 
$img=imageCreatefromjpeg($srcPic); 
break; 
case 3: //png 
$img=imageCreatefrompng($srcPic); 
break; 
default: 
return false; 
} 
return $img; 
} 
/* 功能：为图片加水印图片 
* 参数$groundName: 背景图片，即需要加水印的图片 
* 参数$waterName: 水钱图片 
* 参数#aterPost：水印位置， 10种状态，  
*  0为随机位置 
* 
*  1. 为顶端居左  2. 为顶端居中  3 为顶端居右 
*  4  为中部居左  5. 为中部居中  6 为中部居右 
*  7 . 为底端居左 8. 为底端居中， 9. 为底端居右 
* 
* 参数$qz : 是加水印后的图片名称前缀 
* 返回值：就是处理后图片的名称 
* 
*/ 
function waterMark($groundName, $waterName, $waterPos=0, $qz="wa_"){ 
$groundInfo=$this->getInfo($groundName); 
$waterInfo=$this->getInfo($waterName); 
//水印的位置 
if(!$pos=$this->position($groundInfo, $waterInfo, $waterPos)){ 
return "Picture too small!"; 
} 
$groundImg=$this->getImg($groundName, $groundInfo); 
$waterImg=$this->getImg($waterName, $waterInfo); 
$groundImg=$this->copyImage($groundImg, $waterImg, $pos, $waterInfo); 
return $this->createNewImage($groundImg, $qz.$groundName, $groundInfo); 
} 
private function copyImage($groundImg, $waterImg, $pos, $waterInfo){ 
imagecopy($groundImg, $waterImg, $pos["posX"], $pos["posY"], 0, 0, $waterInfo["width"], $waterInfo["height"]); 
imagedestroy($waterImg); 
return $groundImg; 
} 
private function position($groundInfo, $waterInfo, $waterPos){ 
//需要背景比水印图片大 
if(($groundInfo["width"]< $waterInfo["width"]) ||($groundInfo["height"] < $waterInfo["height"])){ 
return false; 
} 
switch($waterPos){ 
case 1: 
$posX=0; 
$posY=0; 
break; 
case 2: 
$posX=($groundInfo["width"]-$waterInfo["width"])/2; 
$posY=0; 
break; 
case 3: 
$posX=$groundInfo["width"]-$waterInfo["width"]; 
$posY=0; 
break; 
case 4: 
$posX=0; 
$posY=($groundInfo["height"]-$waterInfo["height"]) /2; 
break; 
case 5: 
$posX=($groundInfo["width"]-$waterInfo["width"])/2; 
$posY=($groundInfo["height"]-$waterInfo["height"]) /2; 
break; 
case 6: 
$posX=$groundInfo["width"]-$waterInfo["width"]; 
$posY=($groundInfo["height"]-$waterInfo["height"]) /2; 
break; 
case 7: 
$posX=0; 
$posY=$groundInfo["height"]-$waterInfo["height"]; 
break; 
case 8: 
$posX=($groundInfo["width"]-$waterInfo["width"])/2; 
$posY=$groundInfo["height"]-$waterInfo["height"]; 
break; 
case 9: 
$posX=$groundInfo["width"]-$waterInfo["width"]; 
$posY=$groundInfo["height"]-$waterInfo["height"]; 
break; 
case 0: 
default: 
$posX=rand(0, ($groundInfo["width"]-$waterInfo["width"])); 
$posY=rand(0, ($groundInfo["height"]-$waterInfo["height"])); 
break; 
} 
return array("posX"=>$posX, "posY"=>$posY); 
} 
}