我正在尝试从 URL 中获取熊的图片并将其另存为aabear.jpg. 但是，我的代码失败了。怎么了？
$config['image_library'] = 'gd2';
$config['source_image'] = 'http://thejuxtapositionape.blog.com/files/2012/03/polar-bear-pup.jpg';
$config['create_thumb'] = TRUE;
$config['maintain_ratio'] = TRUE;
$config['width'] = 75;
$config['height'] = 50;
$config['new_image'] = 'aabear.jpg';
$this->load->library('image_lib', $config);