侯波林的blog

在php项目中,或多或少的会碰到 处理图片的问题. 为了实现对图片的批量自动处理,用php写了一个类,经过测试,可以对图片进行指定尺寸的缩放处理.
需要注意的:
1 需要安装php-gd库 .
2 需要确保 save_to 的目录具有写权限

类程序如下:

class Picture
{
    private $_image_type;
    private $_image_width;
    private $_image_height;
    private $_filename;
    private $_save_to;
    /**
     * Init params of this picture
     * param  $file filename include path like(/home/test/test.jpg)
     * param  $file_suffix file_size  
     * param  $swidth
     * param  $sheight 
     * param  $save_to save_file_to  (be sure to have operation)
     * param 
     * return bool
     */
public function __construct( $file , $file_suffix , $new_width ,$new_height , $save_to="./")
    {
        if( !file_exists($file) )
              return false;

        $this->_filename = $file;
        $this->_save_to = $save_to;       
        $this->_changeimagesize( $new_width , $new_height , $file_suffix );
    }
 private function _changeimagesize( $new_width , $new_height , $file_suffix )
    {
          
        list( $width , $height , $this->_image_type ) = getimagesize( $this->_filename );
        $image_handler = imagecreatetruecolor( $new_width , $new_height );
          
        //1=gif , 2=jpg , 3=png
        if( $this->_image_type == 2 )
        {
            $image = imagecreatefromjpeg( $this->_filename );
            $type='jpeg';
        }else if ( $this->_image_type == 1 )
        {
            $image = imagecreatefromgif( $this->_filename );
            $type='gif';
        }else if ( $this->_image_type == 3 )
        {
            $image = imagecreatefrompng( $this->_filename );
            $type='png';
        }else
        {
            return false;
        }
       
        if( !headers_sent() ) header('Content-type:image/'.$type);
          
        imagecopyresampled( $image_handler , $image , 0 , 0 ,0 , 0 ,$new_width , $new_height , $width , $height );
 if( $this->_image_type == 2 )
        {
            imagejpeg( $image_handler , $save_to.$file_suffix , 100 );  
        }else if ( $this->_image_type == 3  )
        {
            imagepng( $image_handler , $save_to.$file_suffix , 100 );  
        }else if ( $this->_image_type == 1 )
        {
            imagegif( $image_handler , $save_to.$file_suffix , 100 );  
        }
          
        if( !is_file($save_to.$file_suffix) ) return false;
    }

}                                    

使用方法如下:

include("change_pic.php");
                                                                                                                                 
// $file , $file_suffix , $new_width ,$new_height , $save_to="./"
$obj = new Picture( 'girl.jpg' , 'newchange.jpg' , 160 , 120 ,"./image/");
if( !$obj ) 
{
      echo 'Change image size error';
      return false;
}