public async Task <HttpResponseMessage> Post([FromBody] Activity activity)
{
if (activity.Type == ActivityTypes.Message)
{
// Stores send images out of order.
var connector = new ConnectorClient(new Uri(activity.ServiceUrl));
var imageAttachment = activity.Attachments?.FirstOrDefault(a => a.ContentType.Contains("image"));
if (imageAttachment != null)
{
LastImage = await GetImageStream(connector, imageAttachment);
LastImageName = imageAttachment.Name;
LastImageType = imageAttachment.ContentType;
ComputerVisionResult computerVisionResult = await GetImageInfo(LastImage);
LastImageTags = String.Join(", ", computerVisionResult.Tags);
LastImageDescription = computerVisionResult.Description;
String replyText = "Got your image!";
if (!String.IsNullOrWhiteSpace(computerVisionResult.Text))
{
replyText += $" It probably shows { computerVisionResult.Text}.";
}
Activity reply = activity.CreateReply(replyText);
await connector.Conversations.ReplyToActivityAsync(reply);
}
else
{
// Creates a dialog stack for the new conversation, adds MainDialog to the stack, and forwards all messages to the dialog stack.
await Conversation.SendAsync(activity, () => new MainDialog());
}
}
var response = Request.CreateResponse(HttpStatusCode.OK);
return(response);
}
private static async Task <ComputerVisionResult> GetImageInfo(Stream imageStream)
{
ComputerVisionResult result = new ComputerVisionResult();
try
{
// Call cognitive services.
var jsonResult = string.Empty;
using (HttpClient client = new HttpClient())
{
// Request headers.
client.DefaultRequestHeaders.Add("Ocp-Apim-Subscription-Key", ConfigurationManager.AppSettings["AZURE_COGNITIVE_SERVICES_KEY"]);
var queryString = HttpUtility.ParseQueryString(string.Empty);
queryString["visualFeatures"] = "Description,Tags";
queryString["language"] = "en";
// Assemble the URI for the REST API Call.
string uri = ConfigurationManager.AppSettings["AZURE_COGNITIVE_SERVICES_URI"] + queryString;
// Request body. Posts a locally stored JPEG image.
byte[] byteData = null;
using (MemoryStream ms = new MemoryStream())
{
imageStream.CopyTo(ms);
if (ms.Length >= IMAGE_SIZE_LIMIT)
{
throw new ArgumentException($"Images size should be less than {IMAGE_SIZE_LIMIT / 1024} Kb");
}
byteData = ms.ToArray();
}
using (ByteArrayContent content = new ByteArrayContent(byteData))
{
content.Headers.ContentType = new MediaTypeHeaderValue("application/octet-stream");
// Execute the REST API call.
var response = await client.PostAsync(uri, content);
if (response.StatusCode != HttpStatusCode.OK)
{
throw new Exception("Image analysis failed.");
}
// Get the JSON response.
jsonResult = await response.Content.ReadAsStringAsync();
}
}
// Retrieve only tags
JObject json = JObject.Parse(jsonResult);
JToken captions = json["description"]["captions"];
JToken tags = json["tags"];
String caption = captions.First()["text"].Value <String>();
Double captionConfidence = captions.First()["confidence"].Value <Double>();
if (captionConfidence >= 0.8)
{
result.Description = caption;
result.Text = caption;
}
foreach (JToken item in tags)
{
String tag = item["name"].Value <String>();
Double confidence = item["confidence"].Value <Double>();
if (confidence >= 0.8)
{
result.Tags.Add(tag);
if (String.IsNullOrWhiteSpace(result.Text))
{
result.Text = tag;
}
}
}
}
catch (Exception ex)
{
result.Description = ex.Message;
}
return(result);
}