PHP implements techniques for adding text and image watermarks when uploading images,

PHP implements techniques for adding text and image watermarks when uploading images.

The functions implemented in this article are particularly suitable for some shopping malls and photo sites. It shares the ability to add text and image watermarks when uploading images. Picture watermarking techniques are for your reference. The details are as follows

1. water.class.php

<&#63;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.
 */
//给图片添加水印
Class Water{
  //开启水印
  private $watermark_on = '1';
   
  public $water_img;
   
  //水印位置
  public $pos = 1;  
   
  //压缩比
  public $pct = 80;
   
  //透明度
  public $quality = 80;
   
  public $text = '乐趣网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 &#63; $water_img : $this->water_img;
    //水印的开启状态
    $waterimg_on = $this->check($water_img) &#63; 1 : 0;
    //判断是否在原图上操作
    $out_img = $out_img &#63; $out_img : $img;
    //判断水印的位置
    $pos = $pos &#63; $pos : $this->pos;
    //水印文字
    $text = $text &#63; $text : $this->text;
     
     
    $img_info = getimagesize($img);
    $img_w = $img_info[0];
    $img_h = $img_info[1];
    //判断水印图片的类型
     
     
    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];
    }
     
    //建立原图资源
     
    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;
    }
    //确定水印的位置
    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);
    }
     
    //写入图片资源
    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);  
  }
   
  //生成图片类型
  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($w_img);
  return TRUE;
}  
  //验证图片是否存在
    private function check($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

<&#63;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);

3. Rendering

The above is the entire content of this article. I hope it will be helpful to everyone in learning PHP programming.