General questions
What skills do I need in order to use visage|SDK?
Software development skills are required to make use of visage|SDK.
visage|SDK is a Software Development Kit - a set of documented software libraries that software developers can use to integrate Visage Technologies' face tracking, analysis and recognition algorithms into their applications.
Can I install your software on my computer and just run it?
No. visage|SDK is not a finalized application, but a Software Development Kit that you use to develop/integrate your application. This is what your software development team can hopefully do, based on the documentation delivered as part of visage|SDK.
Can you develop an application for me?
Visage Technologies' software development team is available to develop a custom-made application to your requirements, so that you can install it on your computers/devices and run. To do that, we need specific and detailed requirements for the application, including:
What should the application do?
What sort of user interface should it have?
On what kind of computer/device should it run – Windows? iOS? Android? Other?
Some additional remarks on the way of working:
Please note that these are just initial questions to get the discussion going, quite a bit more detail would probably be required, depending on the complexity of your requirements.
Based on the requirements worked out to a suitable level, we could make a Project Proposal, including the time and cost, for building your application.
Please note that working out your requirements and preparing the Project Proposal may be considerable work in itself so, depending on the complexity of your requirements, we may need to charge for that work too.
Your contact person can advise on further details.
Am I entitled to receive technical support?
Most our licenses include initial 5 hours of support, so if you have purchased a license for visage|SDK, then you can use this support (delivered via email).
For the majority of our clients the initial support hours are more than sufficient, but it is also possible to order additional support - your contact person can advise you on this.
If you are evaluating visage|SDK and have technical issues, we will do our best, within reasonable limits, to support your evaluation.
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:
error report, including the error messages you receive and anything else you think may help our team resolve the issue,
the operating system you are using,
the version of visage|SDK (please see it in the upper left corner of the documentation as in the image below).
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 users 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 with React Native?
visage|SDK does not currently provide direct support for React Native.
For users willing to experiment, there is an undocumented workaround that allows use of visage|SDK in React Native.
visage|SDK is implemented in C++ and provides C++ API, therefore direct calls from React Native are not possible without a wrapper with C-interface functions. Example of such a wrapper is provided in visage|SDK in the form of VisageTrackerUnity Plugin which provides simpler, high-level API through a C-interface. It is intended for integration with Unity3D (in C# with P/Invoke), however it can also be used by other applications/languages that support importing and calling C-functions from a native library, including React Native.
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: https://www.visagetechnologies.com/downloads/visageSDK-rPI-linux_v8.4.tar.bz2
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:
Because of very low demand we currently provide visage|SDK for rPI on-demand only.
The package you have received is visage|SDK 8.4. The latest release is visage|SDK 8.7 but that is not available for rPI yet. If your initial tests prove interesting we will need to discuss the possibility to build the latest version on-demand for you. visage|SDK 8.7 provides better performance and accuracy, but the API is mostly unchanged so you can run relevant initial tests.
visage|SDK 8.4 for rPI has been tested with rPI3b+; it should work with rPI4 but we have not tested that.
Important notes:
Because of very low demand we currently provide visage|SDK for rPI on-demand only.
The package you have received is visage|SDK 8.4. The latest release is visage|SDK 8.7 but that is not available for rPI yet. If your initial tests prove interesting we will need to discuss the possibility to build the latest version on-demand for you. visage|SDK 8.7 provides better performance and accuracy, but the API is mostly unchanged so you can run relevant initial tests.
visage|SDK 8.4 for rPI has been tested with rPI3b+; it should work with rPI4 but we have not tested that.
Will visage|SDK for HTML5 work in browsers on smartphones?
The HTML5 demo page (https://visagetechnologies.com/demo/) 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.
(https://stackoverflow.com/questions/59190472/webrtc-in-chrome-ios)
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.
See also:
libVLC (C++): https://wiki.videolan.org/LibVLC_Tutorial/
libVLC (C#): https://github.com/videolan/libvlcsharp
VideoLAN VLC Media Player: https://www.videolan.org/vlc/index.html
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.
Register all students in a school, let’s say 2000 of them, by doing the following for each (presuming you have their images):
run face tracker on the image to find the face (VisageTracker.Track()) and obtain the FaceData;
use VisageFaceRecognition.AddDescriptor () to get the face descriptor and add it to the gallery of known faces together with the name or ID of the student;
save the galery using VisageFaceRecognition.SaveGallery().
Then, for each person arriving at the identification point (gate, POS etc.):
run face tracker on live camera image to find the face (VisageTracker.Track()) and obtain the FaceData;
pass FaceData to VisageFaceRecognition.ExtractDescriptor() to get the face descriptor of the person;
pass this descriptor to VisageFaceRecognition.Recognize(), which will match it to all the descriptors you have previously stored in the gallery and return the name of the most similar student;
the Recognize() function also returns a similarity value, which you may use to cut off the false positives.
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.
In each of the two images (live face and ID image), there should be only one face, clearly visible.
If that is not the case, e.g. if there is no face or there are two or more faces, you can use visage|SDK to detect this and report an error.
The ID image should be cropped so that the ID is occupying most of the image.
visage|SDK face tracking API will be used to detect the face in each image.
visage|SDK face recognition API will then be used to generate a numerical descriptor for each of the two faces, to compare the two numerical descriptors to each other and return a measure of their similarity.
visage|SDK provides functions to do all the above steps, but you need to use these functions to program the integrated application.
Need to insert links to relevant API parts in text and/or as “See also” section.