PHP图像大小调整了我的图像。

I have this function here.....

这里有一个函数。

function create_thumbnail($source,$destination, $thumb_width) {
        $size = getimagesize($source);
        $width = $size[0];
        $height = $size[1];
        $x = 0;
        $y = 0;
        if($width> $height) {
            $x = ceil(($width - $height) / 2 );
            $width = $height;
        } elseif($height> $width) {
            $y = ceil(($height - $width) / 2);
            $height = $width;
        }
        $new_image = imagecreatetruecolor($thumb_width,$thumb_width)or die('Cannot Initialize new GD image stream');
        $extension = get_image_extension($source);
         if($extension=='jpg' || $extension=='jpeg') 
            $image = imagecreatefromjpeg($source); 
        if($extension=='gif') 
            $image = imagecreatefromgif($source); 
        if($extension=='png') 
            $image = imagecreatefrompng($source);   

        imagecopyresampled($new_image,$image,0,0,$x,$y,$thumb_width,$thumb_width,$width,$height);
        if($extension=='jpg' || $extension=='jpeg') 
           imagejpeg($new_image,$destination); 
        if($extension=='gif') 
            imagegif($new_image,$destination); 
        if($extension=='png') 
            imagepng($new_image,$destination); 
    }
fun