本文實現(xiàn)的功能特別適用于一些商城和圖片站中，分享了圖片在上傳時添加文字和圖片水印的技巧，供大家參考，具體內(nèi)容如下

1. water.class.php

<?php

header('Content-Type:text/html;charset=utf-8');

/* 

 * To change this license header, choose License Headers in Project Properties.

 * To change this template file, choose Tools | Templates

 * and open the template in the editor.

 */

//給圖片添加水印

Class Water{

  //開啟水印

  private $watermark_on = '1';

  public $water_img;

  //水印位置

  public $pos = 1;  

  //壓縮比

  public $pct = 80;

  //透明度

  public $quality = 80;

  public $text = '樂趣網(wǎng)zlblog.sinaapp.com';

  public $size = 12;

  public $color = '#000000';

  public $font = 'font.ttf';

  public function watermark( $img,$pos='',$out_img='',$water_img='',$text='' ){

    if(!$this->check($img) || !$this->watermark_on) return false;

    $water_img = $water_img ? $water_img : $this->water_img;

    //水印的開啟狀態(tài)

    $waterimg_on = $this->check($water_img) ? 1 : 0;

    //判斷是否在原圖上操作

    $out_img = $out_img ? $out_img : $img;

    //判斷水印的位置

    $pos = $pos ? $pos : $this->pos;

    //水印文字

    $text = $text ? $text : $this->text;

    $img_info = getimagesize($img);

    $img_w = $img_info[0];

    $img_h = $img_info[1];

    //判斷水印圖片的類型

    if( $waterimg_on ){

      $w_info = getimagesize($water_img);

      $w_w = $w_info[0];

      $w_h = $w_info[1];

      if ( $img_w < $w_w || $img_h < $w_h ) return false;

      switch ( $w_info[2] ){

        case 1:

          $w_img = imagecreatefromgif($water_img);

          break;

        case 2:

          $w_img = imagecreatefromjpeg($water_img);

          break;

        case 3:

          $w_img = imagecreatefrompng($water_img);

          break;

      }

    }else{

      if( empty($text) || strlen($this->color)!=7 ) return FALSE;

      $text_info = imagettfbbox($this->size, 0, $this->font, $text);

      $w_w = $text_info[2] - $text_info[6];

      $w_h = $text_info[3] - $text_info[7];

    }

    //建立原圖資源

    switch ( $img_info[2] ){

      case 1:

        $res_img = imagecreatefromgif($img);

        break;

      case 2:

        $res_img = imagecreatefromjpeg($img);

        break;

      case 3:

        $res_img = imagecreatefrompng($img);

        break;

    }

    //確定水印的位置

    switch ( $pos ){

      case 1:

        $x = $y =25;

        break;

      case 2:

        $x = ($img_w - $w_w)/2; 

        $y = 25;

        break;

      case 3:

        $x = $img_w - $w_w;

        $y = 25;

        break;

      case 4:

        $x = 25;

        $y = ($img_h - $w_h)/2;

        break;

      case 5:

        $x = ($img_w - $w_w)/2; 

        $y = ($img_h - $w_h)/2;

        break;

      case 6:

        $x = $img_w - $w_w;

        $y = ($img_h - $w_h)/2;

        break;

      case 7:

        $x = 25;

        $y = $img_h - $w_h;

        break;

      case 8:

        $x = ($img_w - $w_w)/2;

        $y = $img_h - $w_h;

        break;

      case 9:

        $x = $img_w - $w_w;

        $y = $img_h - $w_h;

        break;

      default :

        $x = mt_rand(25, $img_w - $w_w);

        $y = mt_rand(25, $img_h - $w_h);

    }

    //寫入圖片資源

    if( $waterimg_on ){

      imagecopymerge($res_img, $w_img, $x, $y, 0, 0, $w_w, $w_h, $this->pct); 

  }else{

    $r = hexdec(substr($this->color, 1,2));

    $g = hexdec(substr($this->color, 3,2));

    $b = hexdec(substr($this->color, 5,2));

    $color = imagecolorallocate($res_img, $r, $g, $b);

    imagettftext($res_img, $this->size, 0, $x, $y, $color, $this->font, $text);  

  }

  //生成圖片類型

  switch ( $img_info[2] ){

    case 1:

      imagecreatefromgif($res_img,$out_img);

      break;

    case 2:

      //imagecreatefromjpeg($res_img,$out_img);

      imagejpeg($res_img,$out_img);

      break;

    case 3:

      imagejpeg($res_img,$out_img);

      break;

  }

  if(isset($res_img)) imagedestroy ($res_img);

  if(isset($w_img))  imagedestroy($w_img);

  return TRUE;

}  

  //驗證圖片是否存在

    private function check($img){

      $type = array('.jpg','.jpeg','.png','.gif');

      $img_type = strtolower(strrchr($img, '.'));

      return extension_loaded('gd') && file_exists($img) && in_array($img_type, $type);

    } 

}

2. test1.php

<?php

/* 

 * To change this license header, choose License Headers in Project Properties.

 * To change this template file, choose Tools | Templates

 * and open the template in the editor.

 */

//header('Content-Type:text/html;charset=utf-8');

include 'water.class.php';

$image = new Water();

$image->watermark('12.jpg',5);

//$image->watermark('12.jpg',1);

以上就是本文的全部內(nèi)容，希望對大家學(xué)習(xí)PHP程序設(shè)計有所幫助。