General questions

Am I entitled to receive technical support?

See also:

How to request technical support?

If you have a technical issue using visage|SDK, please email your Visage Technologies contact person the following information:

This is a reference to the deprecated offline documentation. It needs to be replaced with new instructions how to obtain SDK version.

See also:

Languages, platforms, tools etc.

Can I use visage|SDK with Unity?

visage|SDK packages for Windows, iOS, Android, MAC OS X and HTML5 each provide Unity integration including sample Unity projects with full source code. For more details, please look in the documentation.html which can be found in the root folder of every package of visage|SDK. Specifically, in the documentation, if you click on Samples, then Unity3D, you will find information about Unity integration and relevant sample projects.

This FAQ entry contains pointers to the visage|SDK offline documentation which is deprecated. These pointers need to be replaced with links to online documentation.

Can I use visage|SDK with C#?

For the C# API, please look in the documentation.html (in visage|SDK root folder), under API\C#. This is a managed C# wrapper that exposes all of visage|SDK functionalities – face tracking, analysis and recognition.

The C# API is implemented in libVisageCSWrapper.dll library (libVisageVision.dll is required for running).

Additionally, we provide VisageTrackerUnity Plugin, which is a C# wrapper made specifically for integration with Unity 3D engine. For more information, please take a look at the documentation.html under Samples\Unity3D. The VisageTrackerUnity Plugin comes included with visage|SDK for Windows, MAC OS X, iOS and Android.

This FAQ entry contains pointers to the visage|SDK offline documentation which is deprecated. These pointers need to be replaced with links to online documentation.

Can I use visage|SDK with Java?

visage|SDK is implemented in C++. It provides C++ and C# APIs, but unfortunately currently does not include a Java API. visage|SDK for Android includes JNI-based Java wrappers as part of the sample projects provided in the package; you could use these wrappers as a starting point for your own projects in Java. In conclusion, it is certainly possible to use visage|SDK with Java, but it requires some additional effort for interfacing via JNA wrappers.

Can I use visage|SDK with VB.NET (Visual Basic)?

visage|SDK does not currently provide a VB.NET API.
For users willing to experiment, there is an undocumented and currently unsupported workaround that should allow to use it.
visage|SDK is implemented in C++. It provides C++ and C# APIs. On Windows, the C# API is implemented as a C++/CLI library (VisageCSWrapper) which, in theory, should be usable in other NET languages, e.g. VB.NET. However, we have not tested this. The C# API documentation may be used as a basis for usage of VisageCSWrapper C++/CLI library in VB.NET.

Can I use visage|SDK with Python?

visage|SDK does not currently provide a Python API.
For users willing to experiment, there is an undocumented workaround that allows to use Python.
visage|SDK is implemented in C++ and provides C++ API which cannot easily be used directly in Python without a C functions wrapper. visage|SDK provides such a wrapper in the form of VisageTrackerUnity Plugin which was made specifically for integration with Unity 3D engine however it can also be used by other applications/languages that support importing C functions from a library. At its core the VisageTrackerUnity Plugin is a high-level C functions API wrapper around C++ API. In the case of Python, ctypes library (foreign function library for Python) can be used to import and use C functions from VisageTrackerUnity Plugin. As source code is provided, VisageTrackerUnity Plugin can also be used to implement custom Python wrapper.
Even though it was tested, such usage of VisageTrackerUnity Plugin is not officially supported.

Can I use visage|SDK with UWP?

Our API is a lower-level C++ API and we have no specific UWP integration features, but we see no reason why you would not be able to use it in a UWP app.

Can I use visage|SDK in WebView (in iOS and Android)?

We believe that it should be possible to use visage|SDK in WebView, but we have not tried that nor have any clients currently who have done that so we can not give you a guarantee. Performance will almost certainly be lower than with a native app.

Is there visage|SDK for Raspberry PI?

visage|SDK 8.4 for rPI can be downloaded from the following link:
Once you unpack it, in the root folder you will find the documentation to guide you through the API and the available sample projects.


Important notes:

Important notes:

Will visage|SDK for HTML5 work in browsers on smartphones?

The HTML5 demo page ( contains the list of supported browsers.

Please note that the current HTML5 demos have not been optimized for use in mobile browsers so for best results it is recommended to use a desktop browser.

On iOS, the HTML5 demos work in Safari browser version 11 and higher. They do not work in Chrome and Firefox browsers due to limitations on camera access.

Can I use visage|SDK with an IP camera?

Yes, visage|SDK can be used with any IP camera. However, note that visage|SDK actually does not include camera support as part of the API; the API simply takes a bitmap image. Image grabbing from camera is implemented at the application level.

Our sample projects show how to access local cameras and we currently have no ready-to-go code for accessing IP cameras. There are various ways to grab images from IP cameras, for example using libVLC:
Usually, IP cameras should provide URL from which you can access the raw camera feed and if you can open the URL and see the feed in VideoLAN VLC Media Player ( the same URL can be used in libVLC to access the feed programmatically.

Face Tracking

How many faces can be tracked simultaneously?

The maximum number of faces that can be tracked simultaneously is internally limited to 20 for performance reasons.

Using VisageFeaturesDetector, any number of faces can be detected in an image.

How far from the camera can the face be tracked?

The tracking distance depends on the camera resolution. For example, for a webcam with resolution 1920×1080 (Logitech C920), tracker can be configured to detect and track faces up to ~7.25 meters from the camera (with performance tradeoff).

Face tracking does not work as I expected

Our face tracking algorithm is among the best available, but like all Computer Vision algorithms it has its limits related to image quality, light conditions, occlusions or specific reasons such as head pose.

If you notice specific issues or have special requirements, you may send us your test video footage and any specific requests, and we will process it and send you back the tracking results. This may allow us to fine-tune the tracker configuration to your specific requirements and send you the best possible results.

High-level functionalities

How do I perform liveness detection with visage|SDK?

visage|SDK includes active liveness detection: the user is required to perform a simple facial gesture (smile, blink or eyebrow raising) and face tracking is then used to verify that the gesture is actually performed. You can configure which gesture(s) you want to include. As app developer you also need to take care of displaying appropriate messages to the user.

All visage|SDK packages include the API for liveness detection. However, only the visage|SDK for Windows and visage|SDK for Android contain a ready-to-run demo of Liveness Detection. So, for a quick test of the liveness detection function it would probably be the easiest to downoad visage|SDK for Windows, run “DEMO_FaceTracker2.exe” and select “Perform Liveness” from the Liveness menu.

The technical demos in Android and Windows packages of visage|SDK include the source code intended to help you integrate liveness detection into your own application.

Need to insert links to the documentation of these sample projects and the the Liveness API.

How do I perform identification of a person from a database?

These guidelines are written for a use case of identifying a student from a database of students. They can easily be used for other cases, such as employees.

The main steps involved in implementing the identification process are registration and identification, as follows.

Need to insert links to relevant API parts in text and/or as “See also” section.

How do I perform verification of a live face vs. ID photo?

The scenario is verification of a live face image against the image of a face from an ID.

Need to insert links to relevant API parts in text and/or as “See also” section.