php实现图片上传时添加文字和图片水印技巧

本文实现的功能特别适用于一些商城和图片站中，分享了图片在上传时添加文字和图片水印的技巧，供大家参考，具体内容如下

1. water.class.PHP

rush:PHP;"> 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 ? $water_img : $this->water_img;
//水印的开启状态
$waterimg_on = $this->check($water_img) ? 1 : 0;
//判断是否在原图上操作
$out_img = $out_img ? $out_img : $img;
//判断水印的位置
$pos = $pos ? $pos : $this->pos;
//水印<a href="https://www.jb51.cc/tag/wenzi/" target="_blank" class="keywords">文字</a>
$text = $text ? $text : $this->text;


$img_info = ge<a href="https://www.jb51.cc/tag/timage/" target="_blank" class="keywords">timage</a>size($img);
$img_w = $img_info[0];
$img_h = $img_info[1];
//判断水印<a href="https://www.jb51.cc/tag/tupian/" target="_blank" class="keywords">图片</a>的类型


if( $waterimg_on ){
  $w_info = ge<a href="https://www.jb51.cc/tag/timage/" target="_blank" class="keywords">timage</a>size($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;
  $text_info = imagettfb<a href="https://www.jb51.cc/tag/Box/" target="_blank" class="keywords">Box</a>($this->size,$this->font,$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:
    $res_img = <a href="https://www.jb51.cc/tag/imagecreatefrompng/" target="_blank" class="keywords">imagecreatefrompng</a>($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);
}

//<a href="https://www.jb51.cc/tag/xierutupian/" target="_blank" class="keywords">写入图片</a>资源
if( $waterimg_on ){
  image<a href="https://www.jb51.cc/tag/cop/" target="_blank" class="keywords">cop</a>ymerge($res_img,$w_img,$x,$y,$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,$this->size,$color,$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

rush:PHP;"> /*

• To change this license header,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.效果图

以上就是本文的全部内容，希望对大家学习PHP程序设计有所帮助。

原文地址：https://www.jb51.cc/php/19531.html