php实现常见图片格式的水印和缩略图制作(面向对象)

本文实例为大家分享了php水印和缩略图制作代码，使用面向对象的方法来实现常见图片格式jpg，png，gif的水印和缩略图的制作，供大家参考，具体内容如下

check($img) || !$this->thumb_on) return FALSE;
   
  //定义缩略图的初始值
  $t_type = $t_type ? $t_type : $this->thumb_type;
  $t_w = $t_w ? $t_w : $this->thumb_width;
  $t_h = $t_h ? $t_h : $this->thumb_height;
   
  //获取到原图的信息
  $img_info = getimagesize($img);
  $img_w = $img_info[0];
  $img_h = $img_info[1];
  //取得图像类型的文件后缀
  $img_type = image_type_to_extension($img_info[2]);
  //获取到相关尺寸
  $thumb_size = $this->thumb_size($img_w,$img_h,$t_w,$t_h,$t_type);
  //确定原始图像类型
  //利用自定义函数来实现图片类型的确定
  $func = "imagecreatefrom".substr($img_type, 1);
  $res_img = $func($img);
   
  //缩略图资源   编辑图片资源moon
  if( $img_type == '.gif' || $img_type == '.png' ){
   $res_thumb = imagecreate($thumb_size[0], $thumb_size[1]);
   $color = imagecolorallocate($res_thumb, 255, 0, 0);
  }else{
   $res_thumb = imagecreatetruecolor($thumb_size[0], $thumb_size[1]);
  }
   
  //制作缩略图
  if(function_exists( "imagecopyresampled" ) ){
   imagecopyresampled($res_thumb, $res_img, 0, 0, 0, 0, $thumb_size[0],$thumb_size[1],$thumb_size[2],$thumb_size[3]);
  }else{
   imagecopyresized($res_thumb, $res_img, 0, 0, 0, 0, $thumb_size[0],$thumb_size[1],$thumb_size[2],$thumb_size[3]);
  }
  //处理透明色
  if( $img_type =='.gif' || $img_type == '.png' ){
   imagecolortransparent($res_thumb,$color);
  }
   
  //配置输出文件名
  $outfile = $outfile ? $outfile : $outfile.substr($img,0,strripos($img,'.')).$this->thumb_fix.$img_type;
   
  //文件的保存输出
  $func = "image".substr($img_type, 1);
  $func($res_thumb,$outfile);
  if(isset($res_thumb)) imagedestroy ($res_thumb);
  if(isset($res_img)) imagedestroy ($res_img);
  return $outfile;
 } 
 
 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;
  //水印文字
  $text = $text ? $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,$out_img);
   break;
  case 3:
   imagepng($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);
  } 
   
  //获取缩略图的相关比例
  //获取到图片的处理类型
  private function thumb_size( $img_w,$img_h,$t_w,$t_h,$t_type){
   //定义缩略图尺寸
   $w = $t_w;
   $h = $t_h;
    
   //定义图片的原始尺寸
   $cut_w = $img_w;
   $cut_h = $img_h;
    
   //当要目标图像小于缩略图的尺寸时；
   if( $img_w <= $t_w && $img_h < $t_h ){
    $w = $img_w;
    $h = $img_h;
   }else{
    if( !empty($t_type) && $t_type>0 ){
     switch ( $t_type ){
      //当宽度固定时
      case 1:
$h = $t_w/$img_w*$img_h;
break;
      //高度固定时
      case 2:
$w = $t_h/$img_h*$img_w;
break;
      //宽度固定，高度裁切
      case 3:
$cut_h = $img_w/$t_w*$t_h;
break;
      //高度固定，宽度裁切
      case 4:
$cut_w = $img_h/$t_h*$t_w;
break;
      //等比例缩放
      default :
if( ($img_w/$t_w) > ($img_h/$t_h) ){
 $h = $t_w/$img_w*$t_h;
}elseif( ($img_w/$t_w) < ($img_h/$t_h) ){
 $w = $t_h/$img_h*$t_w;
}else{
 $w = $t_w;
 $h = $t_h;
}
     }
    }
     
     
   }
   $arr[0] = $t_w;
   $arr[1] = $t_h;
   $arr[2] = $cut_w;
   $arr[3] = $cut_h;
   return $arr;
 }
}

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