Yoti.FCM 1.2.0

Yoti Face Capture

Face capture user control handles the camera and validates the video stream frame by frame until it finds a valid face.

Dependencies

The package uses C++ libraries so the machines that run the face capture will need to install the Microsoft Visual C++ Redistributable packages.

Usage

1. Add the package dependency in your project.

2. Add the reference xmlns:yotiFCM="clr-namespace:Yoti.FCM;assembly=Yoti.FCM" in the view that will integrate the user control.

3. Render the user control:

   <yotiFCM:FaceCapture FaceDetected="<FaceCapture_FaceDetectedHandler>" />
   

It does not send the image to the Yoti AI service. The FaceDetected event will provide the base64 encoded image ready to be processed by the service. Use the .NET Yoti SDK or any other Yoti SDK (if the image is propagated to a back-end) to send the image and run a prediction.

This is the properties list for the FaceCapture:

Note: FaceCapture implements the interface IFaceCapture:

/// <summary>
/// Represents an entity that is able to detect a face from a stream like a webcam.
/// </summary>
public interface IFaceCapture
{
    /// <summary>
    /// Event that the face capture will trigger each time it detects a face.
    /// </summary>
    event EventHandler<FacesDetectedEventArgs> FaceDetected;

    /// <summary>
    /// Event to handle all inner exceptions from the face capture.
    /// </summary>
    event EventHandler<ExceptionEventArgs> OnError;

    /// <summary>
    /// Event to handle when the camera is ready to start the streaming and capture a face.
    /// </summary>
    event EventHandler ReadyToCapture;

    /// <summary>
    /// Starts the webcam stream and the face detection.
    /// </summary>
    void Play();

    /// <summary>
    /// Stops the webcam stream and the face detection.
    /// </summary>
    void Stop();
}

The package also provides the DefaultConfig class that implements all the configuration fields for the face capture user control.

Available resolutions

The FCM supports the following resolutions in both landscape and portrait modes, managed by the type Resolution:

• HD720P: (1280 x 720) or (720 x 1280)
• HD960P: (1280 x 960) or (960 x 1280)
• ONE_DOT_THREE_MP: (1280 x 1024) or (1024 x 1280)
• TWO_MP: (1600 x 1200) or (1200 x 1600)
• HD1080P: (1920 x 1080) or (1080 x 1920)

To select the portrait resolutions, they use PORTRAIT_ as a prefix. For example PORTRAIT_HD720P.

Stream Transformations

The FCM can apply various transformations to the input stream, allowing flexibility in camera positioning to maximise the capture area based on the use case.

Supported transformations are managed by the type RotationFlipType, which includes:

• RotateNoneFlipNone: Specifies no clockwise rotation and no flipping. (Default)
• Rotate90FlipNone: Specifies a 90-degree clockwise rotation without flipping.
• Rotate180FlipNone: Specifies a 180-degree clockwise rotation without flipping.
• Rotate270FlipNone: Specifies a 270-degree clockwise rotation without flipping.
• RotateNoneFlipX: Specifies no clockwise rotation followed by a horizontal flip.
• Rotate90FlipX: Specifies a 90-degree clockwise rotation followed by a horizontal flip.
• Rotate180FlipX: Specifies a 180-degree clockwise rotation followed by a horizontal flip.
• Rotate270FlipX: Specifies a 270-degree clockwise rotation followed by a horizontal flip.

Note: These transformations are computationally intensive and may affect performance, depending on the resolution and system characteristics.

Localisation

Set the FCM localisation by running the following code:

CultureInfo cultureInfo = new CultureInfo(SelectedLanguage);
Thread.CurrentThread.CurrentCulture = cultureInfo;
Thread.CurrentThread.CurrentUICulture = cultureInfo;
Application.Current.MainWindow.Language = XmlLanguage.GetLanguage(CultureInfo.CurrentCulture.IetfLanguageTag);

Where SelectedLanguage can be chosen from the following list:

• ar-XM
• bg-BG
• cs-CZ
• da-DK
• de-DE
• el-GR
• en
• es-419
• es-ES
• et-EE
• fa-IR
• fi-FI
• fr-FR
• he-IL
• hi-IN
• hr-HR
• hu-HU
• hy-AM
• id-ID
• it-IT
• ja-JP
• ko-KR
• lt-LT
• lv-LV
• ms-MY
• nb-NO
• nl-NL
• pl-PL
• pt-BR
• pt-PT
• ro-RO
• ru-RU
• sv-SE
• th-TH
• tr-TR
• uk-UA
• ur-PK
• vi-VN

Error handling

The OnError event provides the custom ExceptionEventArgs information with the exceptions that the FCM can throw. It is triggered in the following scenarios:

• The integrator provides an invalid configuration (Yoti.FCM.FaceDetection.Exceptions.ConfigurationException).
• The webcam index is out of range (System.ArgumentOutOfRangeException).
• If the current webcam streaming is disconnected (Yoti.FCM.Exceptions.WebcamStreamException).
• The capture process reach the stablished timeout (System.TimeoutException).
• Unexpected exceptions (System.Exception).

Other controls

Webcam selector

The package exports the method Yoti.FCM.WebcamStream.WebcamInfo.GetWebcamDevices() to get all webcam devices that are available. It also provides a user control to select a webcam:

<controls:WebcamSelector Width="300" Height="24" SelectionChanged="WebcamSelector_SelectionChanged" />

The properties for the webcam selector are the following:

Resolution selector

The package exports the method Yoti.FCM.WebcamStream.WebcamCapabilities.GetValidCapabilities(string webcamMoniker) to get all the capabilities compatible with the FCM for the provided device. It also provides a user control to select capabilities set:

<controls:ResolutionSelector Width="300" Height="24" SelectedWebcam="{Binding CurrentWebcam.MonikerString}" SelectionChanged="ResolutionSelector_SelectionChanged"/>

The properties for the webcam selector are the following: