PHP图片缩略图处理

     也是为了某项目的需要,自己写的一个,纯粹是为了记录下了,以后使用或者修改.  又是一个晚自习...

class images
{
 	public function ChangeSize($file,$new_file,$width,$height)
	{
		$res = $this->loadImgRes($file);
		if($res == false)
		{
			return false;
		}
		$originwidth = imagesx($res);
		$originheight = imagesy($res);
		
		$new_res = imagecreate($width,$height);
		if(imagecopyresampled($new_res,$res,0,0,0,0,$width,$height,$originwidth,$originheight))
		{
			if($this->saveImg($new_res,$new_file))
			{
				imagedestroy($res);
				imagedestroy($new_res);	
				return true;
			}
			else
			{
				return false;	
			}
		}
		else
		{
			return false;
		}

	}
	
	public function Thumbnail($file,$new_file,$max_width,$max_height)
	{
		$res = $this->loadImgRes($file);
		$x = imagesx($res);
		$y = imagesy($res);
		if($res == false)
		{
			return false;
		}
		if($x > $max_width || $y > $max_height)
		{
			$x_scale = (int)($x / $max_width);
			$y_scale = (int)($y / $max_height);
			$scale = $x_scale > $y_scale?$x_scale:$y_scale;
			$this->ChangeSize($file,$new_file,(int)($x / $scale),(int)($y / $scale));
		}
		return true;
	}
	

	private function loadImgRes(&$file)
	{
		if(!file_exists($file))
		{
			return false;	
		}
		switch(strtolower($this->getFileType($file)))
		{
			case "gif":
				if(function_exists("imagecreatefromgif"))
				{
					return imagecreatefromgif($file);
				}
				else
				{
					return false;	
				}
			case "png":
				if(function_exists("imagecreatefrompng"))
				{
					return imagecreatefrompng($file);
				}
				else
				{
					return false;	
				}
			case "jpeg":
				if(function_exists("imagecreatefromjpeg"))
				{
					return imagecreatefromjpeg($file);
				}
				else
				{
					return false;	
				}
			case "jpg":
				if(function_exists("imagecreatefromjpeg"))
				{
					return imagecreatefromjpeg($file);
				}
				else
				{
					return false;	
				}
			default:
				return false;	
		}
	}
	
	private function saveImg(&$res,$newfile)
	{
		switch(strtolower($this->getFileType($newfile)))
		{
			case "gif":
				@imagegif($res,$newfile);
				return true;
			case "png":	
				@imagepng($res,$newfile);
				return true;
			case "jpeg":
				@imagejpeg($res,$newfile);
				return true;
			case "jpg":
				@imagejpeg($res,$newfile);
				return true;
			default:
				return false;
		}
	}

	private function getFileType($name)
	{
		$arr = explode('.',$name);
		return $arr[count($arr) - 1];
	}
}

 路径一定要处理好,先前没处理好还以为是编码的问题...

$a = new images;
$LF = "D:\WebServer\PHPnow\htdocs\u\\1.jpg";
$NF = "D:\WebServer\PHPnow\htdocs\u\\2.jpg";
$a->Thumbnail($LF,$NF,300,300);