php实现图片添加文字水印程序代码

/*PHP图片加文字水印类库
该类库暂时只支持文字水印，位置为右下角，颜色随机

调用方法：
1、在需要加水印的文件顶部引入类库：
include_once 'imageClass.php';
2、声明新类：
$tpl=new image_fu;
3、给图片水印提供参数：
$tpl->img(图片路径,水印文字,字体路径,字体大小,字体角度);
比如：$tpl->img('abc.jpg','这是水印文字','ziti.ttf',30,0)
*/

代码如下：

watermark.php
class image_fu{

private $image;
private $img_info;
private $img_width;
private $img_height;
private $img_im;
private $img_text;
private $img_ttf='';
private $img_new;
private $img_text_size;
private $img_jd;

function img($img='',$txt='',$ttf='',$size=12,$jiaodu=0){
if(isset($img)&&file_exists($img)){//检测图片是否存在
$this->image   =$img;
$this->img_text=$txt;
$this->img_text_size=$size;
$this->img_jd=$jiaodu;
if(file_exists($ttf)){
$this->img_ttf=$ttf;
}else{
exit('字体文件：'.$ttf.'不存在！');
}
$this->imgyesno();
}else{
exit('图片文件:'.$img.'不存在');
}
}

private function imgyesno(){

$this->img_info  =getimagesize($this->image);
$this->img_width =$this->img_info[0];//图片宽
$this->img_height=$this->img_info[1];//图片高

//检测图片类型
switch($this->img_info[2]){
case 1:$this->img_im = imagecreatefromgif($this->image);break;
case 2:$this->img_im = imagecreatefromjpeg($this->image);break;
case 3:$this->img_im = imagecreatefrompng($this->image);break;
default:exit('图片格式不支持水印');
}

$this->img_text();
}

private function img_text(){

imagealphablending($this->img_im,true);

//设定颜色
$color=imagecolorallocate($this->img_im,rand(0,255),rand(0,255),rand(0,255));
$txt_height=$this->img_text_size;
$txt_jiaodu=$this->img_jd;
$ttf_im=imagettfbbox($txt_height,$txt_jiaodu,$this->img_ttf,$this->img_text);
$w = $ttf_im[2] - $ttf_im[6];
$h = $ttf_im[3] - $ttf_im[7];
//$w = $ttf_im[7];
//$h = $ttf_im[8];

unset($ttf_im);

$txt_y     =$this->img_height-$h;
$txt_x     =$this->img_width-$w;
//$txt_y     =0;
//$txt_x     =0;

$this->img_new=@imagettftext($this->img_im,$txt_height,$txt_jiaodu,$txt_x,$txt_y,$color,

$this->img_ttf,$this->img_text);

@unlink($this->image);//删除图片
switch($this->img_info[2]) {//取得背景图片的格式
case 1:imagegif($this->img_im,$this->image);break;
case 2:imagejpeg($this->img_im,$this->image);break;
case 3:imagepng($this->img_im,$this->image);break;
default: exit('水印图片失败');
}

}

//显示图片
function img_show(){echo '';}

//释放内存
private function img_nothing(){
unset($this->img_info);
imagedestroy($this->img_im);
}

}

$addwk    =    new image_fu();
$addwk->img('2.jpg','testwatermark','华康少女字体.ttf',33,0);
$addwk->img_show();   //调用显示图片

?>