using System;

using System.IO;

using System.Net.Http;

using System.Net.Http.Headers;

using System.Threading.Tasks;

namespace Microsoft.Azure.CognitiveServices.Samples.ComputerVision.DetectObjects

{

using Newtonsoft.Json.Linq;

class Program

{

// Add your Azure Computer Vision subscription key and endpoint to your environment variables

public const string subscriptionKey = Environment.GetEnvironmentVariable("COMPUTER_VISION_SUBSCRIPTION_KEY");

public const string endpoint = Environment.GetEnvironmentVariable("COMPUTER_VISION_ENDPOINT");

static void Main(string[] args)

{

DetectObjectSample.RunAsync(endpoint, subscriptionKey).Wait(5000);

Console.WriteLine("\nPress ENTER to exit.");

Console.ReadLine();

}

}

public class DetectObjectSample

{

public static async Task RunAsync(string endpoint, string key)

{

Console.WriteLine("Detect objects in images:");

string imageFilePath = @"Images\objects.jpg"; // See this repo's readme.md for info on how to get these images. Alternatively, you can just set the path to any appropriate image on your machine.

string remoteImageUrl = "https://github.com/Azure-Samples/cognitive-services-sample-data-files/raw/master/ComputerVision/Images/celebrities.jpg";

await DetectObjectsFromStreamAsync(imageFilePath, endpoint, key);

await DetectObjectsFromUrlAsync(remoteImageUrl, endpoint, key);

}

static async Task DetectObjectsFromStreamAsync(string imageFilePath, string endpoint, string subscriptionKey)

{

if (!File.Exists(imageFilePath))

{

Console.WriteLine("\nInvalid file path");

return;

}

try

{

HttpClient client = new HttpClient();

// Request headers.

client.DefaultRequestHeaders.Add("Ocp-Apim-Subscription-Key", subscriptionKey);

string uri = $"{endpoint}/vision/v2.0/detect";

// Read the contents of the specified local image into a byte array.

byte[] byteData = GetImageAsByteArray(imageFilePath);

// Add the byte array as an octet stream to the request body.

using (ByteArrayContent content = new ByteArrayContent(byteData))

{

// This example uses the "application/octet-stream" content type.

// The other content types you can use are "application/json" and "multipart/form-data".

content.Headers.ContentType = new MediaTypeHeaderValue("application/octet-stream");

// Asynchronously call the REST API method.

HttpResponseMessage response = await client.PostAsync(uri, content);

// Asynchronously get the JSON response.

string contentString = await response.Content.ReadAsStringAsync();

// Display the JSON response.

Console.WriteLine("\nResponse:\n\n{0}\n", JToken.Parse(contentString).ToString());

}

}

catch (Exception e)

{

Console.WriteLine("\n" + e.Message);

}

}

static byte[] GetImageAsByteArray(string imageFilePath)

{

// Open a read-only file stream for the specified file.

using (FileStream fileStream = new FileStream(imageFilePath, FileMode.Open, FileAccess.Read))

{

// Read the file's contents into a byte array.

BinaryReader binaryReader = new BinaryReader(fileStream);

return binaryReader.ReadBytes((int)fileStream.Length);

}

}

static async Task DetectObjectsFromUrlAsync(string imageUrl, string endpoint, string subscriptionKey)

{

if (!Uri.IsWellFormedUriString(imageUrl, UriKind.Absolute))

{

Console.WriteLine("\nInvalid remote image url:\n{0} \n", imageUrl);

return;

}

try

{

HttpClient client = new HttpClient();

// Request headers

client.DefaultRequestHeaders.Add("Ocp-Apim-Subscription-Key", subscriptionKey);

string uri = $"{endpoint}/vision/v2.0/detect";

string requestBody = " {\"url\":\"" + imageUrl + "\"}";

var content = new StringContent(requestBody);

content.Headers.ContentType = new MediaTypeHeaderValue("application/json");

// Post the request and display the result

HttpResponseMessage response = await client.PostAsync(uri, content);

string contentString = await response.Content.ReadAsStringAsync();

Console.WriteLine("\nResponse:\n\n{0}\n", JToken.Parse(contentString).ToString());

}

catch (Exception e)

{

Console.WriteLine("\n" + e.Message);

}

}

}

}