文字识别/ocr sdk在php8.1以上无法安装的自行实现解决方式，供参考

[shaohangit]

自行实现文字识别API的调用，首先需要将要识别的图片上传到阿里云的上海oss，得到上传的图片得到的oss对象的url，参考代码如下

        use OSS\OssClient;
        ……
        $accessKeyId = 'your access key id for oss';
        $accessKeySecret = 'your access key secret for oss';
        $bucket = 'the bucket you use';
        $endpoint = 'oss-cn-shanghai.aliyuncs.com';
        $objectPath = 'path used in oss bucket for your file';
        try {
            $ossClient = new OssClient($accessKeyId, $accessKeySecret, $endpoint);
            $ossClient->uploadFile($bucket, $objectPath, 'absolute path of the file that you want to recognize character from');
            // $ossClient->deleteObject($bucket, $objectPath);
        } catch (Exception $e) {
            throw new Exception("Failed to upload file for recognizing character. Exception message is " . $e->getMessage());
        }
        $fileOssUrl = 'https://' . $bucket . '.' . $endpoint . '/' . $objectPath;

然后生成调用文字识别API所需的签名，使用包含上边得到的oss对象url在内的若干参数，调用文字识别API（使用了GuzzleHttp）

        use GuzzleHttp\Client;
        ……
        $accessKeyId = 'your access key id for ocr';
        $accessKeySecret = 'your access key secret for ocr';
        $params = [
            'SignatureMethod' => 'HMAC-SHA1',
            'SignatureNonce' => md5(microtime(true)),
            'AccessKeyId' => $accessKeyId,
            'SignatureVersion' => '1.0',
            'Timestamp' => (new DateTime('now', new DateTimeZone('GMT')))->format("Y-m-d\\TH:i:s\\Z"),
            'Format' => 'JSON',
            'RegionId' => 'cn-shanghai',
            'Version' => '2019-12-30',

            'Action' => 'RecognizeCharacter',
            'ImageURL' => $fileOssUrl,
            'MinHeight' => 5,
            'OutputProbability' => 'true',
        ];
        ksort($params);
        $paramsStr = '';
        foreach ($params as $key => $value) {
            $paramsStr .= '&' . $this->encodeForSignature($key) . '=' . $this->encodeForSignature($value);
        }
        $paramsStr = substr($paramsStr, 1);
        $strToSign = 'POST&' . $this->encodeForSignature('/') . '&' . $this->encodeForSignature($paramsStr);
        $signature = $this->encodeForSignature(base64_encode(hash_hmac('sha1', $strToSign, $accessKeySecret . '&', true)));
        try {
            $client = new Client();
            $response = $client->post("https://ocr.cn-shanghai.aliyuncs.com?Signature={$signature}&{$paramsStr}");
            if ($response->getStatusCode() == 200) {
                $apiResult = json_decode($response->getBody()->getContents(), true);
            }
        } catch (Exception $e) {
        }

如果在得到文字识别结果之后，希望删除oss中的对象，使用第一段示例代码中注释掉的代码即可

[TsinghuaDream]

测试看SDK在PHP8.2.3是可用的，是使用上遇到了什么问题吗？