php 将图片转为base64

    /**
     * 获取图片转为base64
     * @param string $avatar
     * @return bool|string
     */
    function image_to_base64($avatar = '', $timeout = 9)
    {
        try {
            $url = parse_url($avatar);
            $url = $url['host'];
            $header = [
                'User-Agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:45.0) Gecko/20100101 Firefox/45.0',
                'Accept-Language: zh-CN,zh;q=0.8,en-US;q=0.5,en;q=0.3',
                'Accept-Encoding: gzip, deflate, br',
                'accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9',
                'Host:' . $url
            ];
            $dir = pathinfo($url);
            $host = $dir['dirname'];
            $refer = $host . '/';
            $curl = curl_init();
            curl_setopt($curl, CURLOPT_REFERER, $refer);
            curl_setopt($curl, CURLOPT_URL, $avatar);
            curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
            curl_setopt($curl, CURLOPT_FOLLOWLOCATION, true);
            curl_setopt($curl, CURLOPT_ENCODING, 'gzip');
            curl_setopt($curl, CURLOPT_CONNECTTIMEOUT, $timeout);
            curl_setopt($curl, CURLOPT_HTTPHEADER, $header);
            $data = curl_exec($curl);
            $code = curl_getinfo($curl, CURLINFO_HTTP_CODE);
            curl_close($curl);
            if ($code == 200) {
                return "data:image/jpeg;base64," . base64_encode($data);
            } else {
                return false;
            }
        } catch (\Exception $e) {
            return false;
        }
    }