如何利用PHP和阿里云OCR进行文本关键词提取？

<?php

require 'vendor/autoload.php';

use AliyunOSSOSSClient;
use AliyunOSSCoreOssException;
use AliyunOSSOcrOcrClient;
use AliyunOSSCoreAuth;
use AliyunOSSOcrModelsRecognizeBankCardRequest;

// 设置阿里云的Access Key信息
$accessKeyId = ''; // 在阿里云官网获取
$accessKeySecret = ''; // 在阿里云官网获取

// 设置OCR请求的相关参数
$endpoint = ''; // OCR服务的Endpoint，例如：oss-cn-shanghai.aliyuncs.com
$bucketName = ''; // 保存图片的Bucket名称
$imagePath = ''; // 图片路径

// 初始化OSSClient和OcrClient
$ossClient = new OSSClient($accessKeyId, $accessKeySecret, $endpoint);
$ocrClient = new OcrClient($accessKeyId, $accessKeySecret, $endpoint);

// 上传图片到OSS
try {
    $ossClient->uploadFile($bucketName, 'image.jpg', $imagePath);
} catch (OssException $e) {
    die("上传图片失败：" . $e->getMessage());
}

// 调用OCR接口识别关键词
try {
    $request = new RecognizeBankCardRequest();
    $request->setImageUrl('http://'.$bucketName.'.'.$endpoint.'/image.jpg');
    $response = $ocrClient->recognizeBankCard($request);
    $words = $response->getData()['words_result'];
    foreach ($words as $word) {
        echo $word['word'] . "
";
    }
} catch (Exception $e) {
    die("识别关键词失败：" . $e->getMessage());
}