php 图片处理类_PHP教程

private function createNewImage($newImg, $newName, $imgInfo){
switch($imgInfo["type"]){
case 1://gif
$result=imageGif($newImg, $this->path.$newName);
break;
case 2://jpg
$result=imageJPEG($newImg, $this->path.$newName);
break;
case 3://png
$return=imagepng($newImg, $this->path.$newName);
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;

}

private 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_"){

if(file_exists($this->path.$groundName) && file_exists($this->path.$waterName)){
$groundInfo=$this->getInfo($groundName);
$waterInfo=$this->getInfo($waterName);
//水印的位置
if(!$pos=$this->position($groundInfo, $waterInfo, $waterPos)){
echo "水印不应该比背景图片小！";
return;
}

$groundImg=$this->getImg($groundName, $groundInfo);
$waterImg=$this->getImg($waterName, $waterInfo);

$groundImg=$this->copyImage($groundImg, $waterImg, $pos, $waterInfo);

return $this->createNewImage($groundImg, $qz.$groundName, $groundInfo);
}else{
echo "图片或水印图片不存在";
return false;
}
}

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);
}

}

摘自 chaojie2009的专栏