给现有的图片加文字水印php代码

php类库给现有的图片加文字水印，代码不是很完善，欢迎大家多多指教！代码如下：

2. /*PHP图片加文字水印类库
4. QQ:3697578482 伤心的歌
6. 该类库暂时只支持文字水印，位置为右下角，颜色随机
8. 调用方法：
9. 1、在需要加水印的文件顶部引入类库：
10. include_once 'imageClass.php';
11. 2、声明新类：
12. $tpl=new image_fu;
13. 3、给图片水印提供参数：
14. $tpl->img(图片路径,水印文字,字体路径,字体大小,字体角度);
15. 比如：$tpl->img('abc.jpg','这是水印文字','ziti.ttf',30,0)
17. */
19. class image_fu{
21. private $image;
22. private $img_info;
23. private $img_width;
24. private $img_height;
25. private $img_im;
26. private $img_text;
27. private $img_ttf='';
28. private $img_new;
29. private $img_text_size;
30. private $img_jd;
32. function img($img='',$txt='',$ttf='',$size=12,$jiaodu=0){
33. if(isset($img)&&file_exists($img)){//检测图片是否存在
34. $this->image =$img;
35. $this->img_text=$txt;
36. $this->img_text_size=$size;
37. $this->img_jd=$jiaodu;
38. if(file_exists($ttf)){
39. $this->img_ttf=$ttf;
40. }else{
41. exit('字体文件：'.$ttf.'不存在！');
42. }
43. $this->imgyesno();
44. }else{
45. exit('图片文件:'.$img.'不存在');
46. }
47. }
49. private function imgyesno(){
51. $this->img_info =getimagesize($this->image);
52. $this->img_width =$this->img_info[0];//图片宽
53. $this->img_height=$this->img_info[1];//图片高
55. //检测图片类型
56. switch($this->img_info[2]){
57. case 1:$this->img_im = imagecreatefromgif($this->image);break;
58. case 2:$this->img_im = imagecreatefromjpeg($this->image);break;
59. case 3:$this->img_im = imagecreatefrompng($this->image);break;
60. default:exit('图片格式不支持水印');
61. }
63. $this->img_text();
64. }
66. private function img_text(){
68. imagealphablending($this->img_im,true);
70. //设定颜色
71. $color=imagecolorallocate($this->img_im,rand(0,255),rand(0,255),rand(0,255));
72. $txt_height=$this->img_text_size;
73. $txt_jiaodu=$this->img_jd;
74. $ttf_im=imagettfbbox($txt_height,$txt_jiaodu,$this->img_ttf,$this->img_text);
75. $w = $ttf_im[2] - $ttf_im[6];
76. $h = $ttf_im[3] - $ttf_im[7];
77. //$w = $ttf_im[7];
78. //$h = $ttf_im[8];
80. unset($ttf_im);
82. $txt_y =$this->img_height-$h;
83. $txt_x =$this->img_width-$w;
84. //$txt_y =0;
85. //$txt_x =0;
87. $this->img_new=@imagettftext($this->img_im,$txt_height,$txt_jiaodu,$txt_x,$txt_y,$color,$this->img_ttf,$this->img_text);
89. @unlink($this->image);//删除图片
90. switch($this->img_info[2]) {//取得背景图片的格式
91. case 1:imagegif($this->img_im,$this->image);break;
92. case 2:imagejpeg($this->img_im,$this->image);break;
93. case 3:imagepng($this->img_im,$this->image);break;
94. default: exit('水印图片失败');
95. }
97. }
99. //显示图片
100. function img_show(){echo '';}
102. //释放内存
103. private function img_nothing(){
104. unset($this->img_info);
105. imagedestroy($this->img_im);
106. }
108. }
110. ?>