// OCR Request by URL & Extract Key-Value Pairs
public static async Task <List <string> > MakeOCRRequestByUrl(string imageUrl, string formType, ExecutionContext executionContext)
{
Console.Write("C# HTTP trigger function processed: MakeOCRRequestByUrl");
string urlBase = Environment.GetEnvironmentVariable("CognitiveServicesUrlBase");
string key = Environment.GetEnvironmentVariable("CognitiveServicesKey");
var client = new HttpClient();
var queryString = HttpUtility.ParseQueryString(string.Empty);
// Request headers
client.DefaultRequestHeaders.Add("Ocp-Apim-Subscription-Key", key);
// Request parameters
queryString["mode"] = "Printed";
Uri uri = new Uri(urlBase + "recognizeText?" + queryString);
HttpResponseMessage response;
var requstbody = "{\"url\":\"" + $"{imageUrl}" + "\"}";
// Request body
byte[] byteData = Encoding.UTF8.GetBytes(requstbody);
using (var content = new ByteArrayContent(byteData))
{
content.Headers.ContentType = new MediaTypeHeaderValue("application/json");
response = await client.PostAsync(uri, content);
}
string operationLocation = null;
// The response contains the URI to retrieve the result of the process.
if (response.IsSuccessStatusCode)
{
operationLocation = response.Headers.GetValues("Operation-Location").FirstOrDefault();
}
string contentString;
int i = 0;
do
{
System.Threading.Thread.Sleep(1000);
response = await client.GetAsync(operationLocation);
contentString = await response.Content.ReadAsStringAsync();
++i;
}while (i < 10 && contentString.IndexOf("\"status\":\"Succeeded\"") == -1);
string json = response.Content.ReadAsStringAsync().Result;
json = json.TrimStart(new char[] { '[' }).TrimEnd(new char[] { ']' });
RecognizeText ocrOutput = JsonConvert.DeserializeObject <RecognizeText>(json);
if (ocrOutput != null && ocrOutput.RecognitionResult != null && ocrOutput.RecognitionResult.Lines != null)
{
List <string> resultText = new List <string>();
resultText = (from Line sline in ocrOutput.RecognitionResult.Lines
select(string) sline.Text).ToList <string>();
// Extract Key-Value Pairs
resultText = OCRHelper.ExtractKeyValuePairs(ocrOutput.RecognitionResult.Lines, formType, executionContext);
return(resultText);
}
else
{
return(null);
}
}