Azure OCR sample

Thing.cs

class Program
{
    static void Main(string[] args)
    {
        // once you create a computer vision service in Azure, you'll get the region and service key
        // CV OCR docs are here: https://eastus2.dev.cognitive.microsoft.com/docs/services/56f91f2d778daf23d8ec6739/operations/56f91f2e778daf14a499e1fc
        
        var recognizer = new Recognizer("<REGION OF YOUR CV SERVICE>", "<CV SERVICE KEY>");
        // here's an example if the image to OCR is on the internet somewhere already
        recognizer.RecognizeFromImageUrl("<URL TO IMAGE, IF AVAILABLE ON INTERNET>", "ar").Wait();

        // here's an example with a local image
        var imageBytes = System.IO.File.ReadAllBytes(@"<LOCAL PATH TO IMAGE ON DISK>");
        recognizer.RecognizeFromImage(imageBytes, "ar").Wait();

        Console.WriteLine("all done, any key to exit");
        Console.ReadLine();
    }
}
    
public class Recognizer
{
    private HttpClient _httpClient;
    private const string OcrServiceUrlBase = "https://{0}.api.cognitive.microsoft.com/vision/v1.0/ocr?language={1}";
    private readonly string _serviceRegion;

    public Recognizer(string serviceRegion, string serviceKey)
    {
        _httpClient = new HttpClient();
        _serviceRegion = serviceRegion;

        _httpClient.DefaultRequestHeaders.Add("Ocp-Apim-Subscription-Key", serviceKey);
    }

    public async Task RecognizeFromImageUrl(string urlToImage, string imageLanguage)
    {
        var serviceUrl = string.Format(OcrServiceUrlBase, _serviceRegion, imageLanguage); // e.g., https://eastus2.api.cognitive.microsoft.com/vision/v1.0/ocr?language=ar
        Console.WriteLine($"OCR URL: {serviceUrl}");

        var postData = $"{{'url': '{urlToImage}'}}";
        var postBody = new StringContent(postData, System.Text.Encoding.UTF8, "application/json");

        Console.WriteLine($"Post body: {postData}");

        try
        {
            var serviceResponse = await _httpClient.PostAsync(serviceUrl, postBody);
            if (!serviceResponse.IsSuccessStatusCode)
            {
                Console.WriteLine(serviceResponse.StatusCode);
                return;
            }

            var responseData = await serviceResponse.Content.ReadAsStringAsync();
            Console.WriteLine(responseData);
        }
        catch (Exception ex)
        {
            Console.WriteLine(ex.Message);
        }
    }

    public async Task RecognizeFromImage(byte[] image, string imageLanguage)
    {
        var serviceUrl = string.Format(OcrServiceUrlBase, _serviceRegion, imageLanguage); // e.g., https://eastus2.api.cognitive.microsoft.com/vision/v1.0/ocr?language=ar
        Console.WriteLine($"OCR URL: {serviceUrl}");

        var postBody = new ByteArrayContent(image);
        postBody.Headers.Remove("Content-Type");
        postBody.Headers.Add("Content-Type", "application/octet-stream");

        try
        {
            var serviceResponse = await _httpClient.PostAsync(serviceUrl, postBody);
            if (!serviceResponse.IsSuccessStatusCode)
            {
                Console.WriteLine(serviceResponse.StatusCode);
                return;
            }

            var responseData = await serviceResponse.Content.ReadAsStringAsync();
            Console.WriteLine(responseData);
        }
        catch (Exception ex)
        {
            Console.WriteLine(ex.Message);
        }
    }
}