Building An Azure Cognitive Services Face App – Part 3 – People, Groups and Persisted Faces

Building on our previous posts, in this post we will show how people and groups functionality works, and how to persist faces to Microsoft Azure.

In our WPF application, add a new button called Create Person:

On pressing this button, we will do the following:

1. We will create a new Person Group, called “My People Group”, using PersonGroup.CreateAsync. We will also set the GUID of this group
2. We will create a new Person, called “Bob Smith”, using PersonGroupPerson.CreateAsync. We will attach this person to our group
3. Once Bob Smith is attached to our group, we will attach a face to Bob Smith using PersonGroupPerson.AddFaceFromStreamAsync. This will be persisted in Azure storage
4. We will then loop through all groups using PersonGroup.ListAsync, and view all people in each group through PersonGroupPerson.ListAsync
5. Finally, we will delete each group using PersonGroup.DeleteAsync

Below is the full source, carrying on from our previous code.

[sourcecode language=”CSharp”] using Microsoft.Azure.CognitiveServices.Vision.Face;
using Microsoft.Azure.CognitiveServices.Vision.Face.Models;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;

namespace Carl.FaceAPI
{
///
<summary>
/// Interaction logic for MainWindow.xaml
/// </summary>

public partial class MainWindow : Window
{
private const string subscriptionKey = "yourkey";

private const string baseUri =
"https://yourregion.api.cognitive.microsoft.com/";

private readonly IFaceClient faceClient = new FaceClient(
new ApiKeyServiceClientCredentials(subscriptionKey),
new System.Net.Http.DelegatingHandler[] { });

IList<DetectedFace> faceList;
String[] faceDescriptions;
double resizeFactor;

public MainWindow()
{
InitializeComponent();

faceClient.Endpoint = baseUri;

}

private async void btnBrowse_Click(object sender, RoutedEventArgs e)
{
var dialog = new Microsoft.Win32.OpenFileDialog();
dialog.Filter = "JPG (*.jpg)|*.jpg";
bool? result = dialog.ShowDialog(this);

if (!(bool)result)
{
return;
}

string filePath = dialog.FileName;
Uri uriSource = new Uri(filePath);
BitmapImage source = new BitmapImage();

source.BeginInit();
source.CacheOption = BitmapCacheOption.None;
source.UriSource = uriSource;
source.EndInit();

Image1.Source = source;

faceList = await UploadAndDetectFaces(filePath);

if (faceList.Count > 0)
{
DrawingVisual visual = new DrawingVisual();
DrawingContext context = visual.RenderOpen();
context.DrawImage(source, new Rect(0, 0, source.Width, source.Height));
double dpi = source.DpiX;
resizeFactor = (dpi > 0) ? 96 / dpi : 1;
faceDescriptions = new String[faceList.Count];

for (int i = 0; i < faceList.Count; ++i)
{
DetectedFace face = faceList[i];

context.DrawRectangle(
Brushes.Transparent,
new Pen(Brushes.Green, 5),
new Rect(
face.FaceRectangle.Left * resizeFactor,
face.FaceRectangle.Top * resizeFactor,
face.FaceRectangle.Width * resizeFactor,
face.FaceRectangle.Height * resizeFactor
)
);
}
context.Close();

RenderTargetBitmap facewithRectangle = new RenderTargetBitmap(
(int)(source.PixelWidth * resizeFactor),
(int)(source.PixelHeight * resizeFactor),
96,
96,
PixelFormats.Default);

facewithRectangle.Render(visual);
Image1.Source = facewithRectangle;
}
}

private async Task<IList<DetectedFace>> UploadAndDetectFaces(string imageFilePath)
{
try
{
IList<FaceAttributeType> faceAttributes =
new FaceAttributeType[] {
FaceAttributeType.Age,
FaceAttributeType.Blur,
FaceAttributeType.Emotion,
FaceAttributeType.FacialHair,
FaceAttributeType.Gender,
FaceAttributeType.Glasses,
FaceAttributeType.Hair,
FaceAttributeType.HeadPose,
FaceAttributeType.Makeup,
FaceAttributeType.Noise,
FaceAttributeType.Occlusion,
FaceAttributeType.Smile
};

using (Stream imageFileStream = File.OpenRead(imageFilePath))
{
IList<DetectedFace> faceList =
await faceClient.Face.DetectWithStreamAsync(
imageFileStream, true, false, faceAttributes);
return faceList;
}
}
catch (APIErrorException f)
{
MessageBox.Show(f.Message);
return new List<DetectedFace>();
}
catch (Exception e)
{
MessageBox.Show(e.Message, "Error");
return new List<DetectedFace>();
}
}

private void btnDetectAttributes_Click(object sender, RoutedEventArgs e)
{
ImageSource imageSource = Image1.Source;
BitmapSource bitmapSource = (BitmapSource)imageSource;

var scale = Image1.ActualWidth / (bitmapSource.PixelWidth / resizeFactor);

for (int i = 0; i < faceList.Count; ++i) { FaceRectangle fr = faceList[i].FaceRectangle; double left = fr.Left * scale; double top = fr.Top * scale; double width = fr.Width * scale; double height = fr.Height * scale; faceDescriptions[i] = FaceDescription(faceList[i]); TextBlock1.Text = TextBlock1.Text + string.Format("Person {0}: {1} \n", i.ToString(), faceDescriptions[i]); } } private string FaceDescription(DetectedFace face) { StringBuilder sb = new StringBuilder(); sb.Append(face.FaceAttributes.Gender); sb.Append(", "); sb.Append(face.FaceAttributes.Age); sb.Append(", "); sb.Append(String.Format("smile {0:F1}%, ", face.FaceAttributes.Smile * 100)); sb.Append("Emotion: "); Emotion emotionScores = face.FaceAttributes.Emotion; if (emotionScores.Anger >= 0.1f)
sb.Append(String.Format("anger {0:F1}%, ", emotionScores.Anger * 100));
if (emotionScores.Contempt >= 0.1f)
sb.Append(String.Format("contempt {0:F1}%, ", emotionScores.Contempt * 100));
if (emotionScores.Disgust >= 0.1f)
sb.Append(String.Format("disgust {0:F1}%, ", emotionScores.Disgust * 100));
if (emotionScores.Fear >= 0.1f)
sb.Append(String.Format("fear {0:F1}%, ", emotionScores.Fear * 100));
if (emotionScores.Happiness >= 0.1f)
sb.Append(String.Format("happiness {0:F1}%, ", emotionScores.Happiness * 100));
if (emotionScores.Neutral >= 0.1f)
sb.Append(String.Format("neutral {0:F1}%, ", emotionScores.Neutral * 100));
if (emotionScores.Sadness >= 0.1f)
sb.Append(String.Format("sadness {0:F1}%, ", emotionScores.Sadness * 100));
if (emotionScores.Surprise >= 0.1f)
sb.Append(String.Format("surprise {0:F1}%, ", emotionScores.Surprise * 100));

sb.Append(face.FaceAttributes.Glasses);
sb.Append(", ");

sb.Append("Hair: ");

if (face.FaceAttributes.Hair.Bald >= 0.01f)
sb.Append(String.Format("bald {0:F1}% ", face.FaceAttributes.Hair.Bald * 100));

IList<HairColor> hairColors = face.FaceAttributes.Hair.HairColor;
foreach (HairColor hairColor in hairColors)
{
if (hairColor.Confidence >= 0.1f)
{
sb.Append(hairColor.Color.ToString());
sb.Append(String.Format(" {0:F1}% ", hairColor.Confidence * 100));
}
}

sb.Append(string.Format("Blur: {0}", face.FaceAttributes.Blur.BlurLevel));
sb.Append(string.Format("Facial Hair: {0}", face.FaceAttributes.FacialHair.Beard));
sb.Append(string.Format("Head Pose: {0}", face.FaceAttributes.HeadPose.Roll));
sb.Append(string.Format("Makeup: {0}", face.FaceAttributes.Makeup.LipMakeup));
sb.Append(string.Format("Noise: {0}", face.FaceAttributes.Noise.NoiseLevel));
sb.Append(string.Format("Occlusion: {0}", face.FaceAttributes.Occlusion.ForeheadOccluded));

return sb.ToString();
}

private async void btnCreatePerson_Click(object sender, RoutedEventArgs e)
{
var dialog = new Microsoft.Win32.OpenFileDialog();
dialog.Filter = "JPG (*.jpg)|*.jpg";
bool? result = dialog.ShowDialog(this);

if (!(bool)result)
{
return;
}

string filePath = dialog.FileName;
Uri uriSource = new Uri(filePath);
BitmapImage source = new BitmapImage();

source.BeginInit();
source.CacheOption = BitmapCacheOption.None;
source.UriSource = uriSource;
source.EndInit();

Image1.Source = source;

CreatePersonandGroup(filePath);
}

private async void CreatePersonandGroup(string imageFilePath)
{
try
{
// Create Person group
string persongroupName = "My People Group";
string persongroupPersonGroupId = Guid.NewGuid().ToString();

await faceClient.PersonGroup.CreateAsync(persongroupPersonGroupId, persongroupName);

// Create person
string personName = "Bob Smith";
string personId = Guid.NewGuid().ToString();

Person p = await faceClient.PersonGroupPerson.CreateAsync(persongroupPersonGroupId, personName);

using (Stream imageFileStream = File.OpenRead(imageFilePath))
{
await faceClient.PersonGroupPerson.AddFaceFromStreamAsync(
persongroupPersonGroupId, p.PersonId, imageFileStream);
}

// Get Groups and Person
IList<PersonGroup> persongroupList = await faceClient.PersonGroup.ListAsync();
foreach (PersonGroup pg in persongroupList)
{
IList<Person> people = await faceClient.PersonGroupPerson.ListAsync(pg.PersonGroupId);
foreach (Person person in people)
{
// Do something with each person
}
// Delete person group
await faceClient.PersonGroup.DeleteAsync(pg.PersonGroupId);
}
}
catch (APIErrorException f)
{
MessageBox.Show(f.Message);
}
catch (Exception e)
{
MessageBox.Show(e.Message, "Error");
}
}
}
}
[/sourcecode]