PHP与阿里云OCR的强强联合：优化文字识别的策略分享

<?php

require 'vendor/autoload.php';

use AlibabaCloudClientAlibabaCloud;
use AlibabaCloudClientExceptionClientException;
use AlibabaCloudClientExceptionServerException;
use AlibabaCloudCloudOCRCloudOCR;
use AlibabaCloudCloudOCRModelsRecognizeLicensePlateRequest;

// 设置阿里云API参数
AlibabaCloud::accessKeyClient('accessKeyId', 'accessKeySecret')
            ->regionId('cn-shanghai')
            ->asDefaultClient();

// 创建请求对象
$request = new RecognizeLicensePlateRequest();
$request->setImageURL('<imageURL>');

try {
    // 调用阿里云OCR服务进行文字识别
    $response = AlibabaCloud::rpc()
                            ->product('CloudOCR')
                            ->version('2019-12-30')
                            ->action('RecognizeLicensePlate')
                            ->method('POST')
                            ->host('ocr.cn-shanghai.aliyuncs.com')
                            ->options([
                                'query' => [
                                    'RegionId' => 'cn-shanghai',
                                    'AccessKeyId' => 'accessKeyId',
                                    'Format' => 'JSON',
                                    'SignatureVersion' => '1.0',
                                    'SignatureMethod' => 'HMAC-SHA1',
                                ],
                            ])
                            ->request();
                            
    // 解析响应结果
    $result = $response->toArray();
    print_r($result);
} catch (ClientException $e) {
    echo $e->getErrorMessage() . PHP_EOL;
} catch (ServerException $e) {
    echo $e->getErrorMessage() . PHP_EOL;
}

?>

<?php
// 图片灰度化函数
function grayscale($im)
{
    $width = imagesx($im);
    $height = imagesy($im);

    for ($x = 0; $x < $width; $x++) {
        for ($y = 0; $y < $height; $y++) {
            $rgb = imagecolorat($im, $x, $y);
            $r = ($rgb >> 16) & 0xFF;
            $g = ($rgb >> 8) & 0xFF;
            $b = $rgb & 0xFF;

            $gray = round(($r + $g + $b) / 3);
            $color = imagecolorallocate($im, $gray, $gray, $gray);
            imagesetpixel($im, $x, $y, $color);
        }
    }

    return $im;
}

// 图片二值化函数
function binarization($im)
{
    $width = imagesx($im);
    $height = imagesy($im);

    for ($x = 0; $x < $width; $x++) {
        for ($y = 0; $y < $height; $y++) {
            $rgb = imagecolorat($im, $x, $y);
            $gray = ($rgb >> 16) & 0xFF;

            $threshold = 127;
            $color = $gray > $threshold ? imagecolorallocate($im, 255, 255, 255) : imagecolorallocate($im, 0, 0, 0);
            imagesetpixel($im, $x, $y, $color);
        }
    }

    return $im;
}

// 调用示例
$im = imagecreatefromjpeg('image.jpg');
$im = grayscale($im);
$im = binarization($im);

<?php
// 请求重试函数
function retryRequest($request)
{
    $maxAttempts = 3;
    $attempt = 0;
    $exception = null;
    $response = null;

    while ($attempt < $maxAttempts) {
        try {
            $response = $request->request();
            $exception = null;
            break;
        } catch (ClientException $e) {
            $exception = $e;
        } catch (ServerException $e) {
            $exception = $e;
        } finally {
            $attempt++;
        }
    }

    if ($exception !== null) {
        echo $exception->getErrorMessage() . PHP_EOL;
    }

    return $response;
}

// 调用示例
$response = retryRequest($request);

?>