php图片添加文字水印实现代码

http://my.oschina.net/zyt1978/blog/638426

<?php
/*PHP图片加文字水印类库
QQ:3697578482 伤心的歌
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)
*/
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 '<img src="' . $this ->image. '" border="0" alt="' . $this ->img_text. '" />' ;}
//释放内存
private function img_nothing(){
unset( $this ->img_info);
imagedestroy( $this ->img_im);
}
}
?>