BioID Identity Hidden Gems
On the corresponding pages on Playground there's a Microsoft Silverlight control embedded to record images and audio for the biometric traits face and voice. You can also upload samples from your local disk if you don't have a web cam or microphone connected (or no Silverlight installed) but in this blog post we want to explain some features of the control you may not have noticed yet.
First you have to enable the devices with the On button below the image preview window. There you can either use the Photo button to capture single images or the Audio button to record an audio sample. The audio recording will stop automatically after 2 seconds.
In the box below the buttons the sample previews will be shown after recording but we'll look further into that later.
On the right side of the camera preview image is a button with an arrow. If you click on that button a pane will open to the right where the video and audio device settings can be changed.
On top you can select the video source or camera device if there's more than one connected to your computer. Beneath the video device selection you can change the video quality of the device. Same applies to the audio source settings below. At the bottom of the panel you can enable the motion detector.
If the motion detector is enabled and the Photo button is selected an indicator is shown on the left of the preview image.
The green bar of the indicator displays the trigger of the motion detector. If the motion detector is enabled a first image will be captured immediately after the Photo button is pressed and a second one if a motion triggers the camera.
This is very handy if the liveness detection is used. On the BioID Verification page the motion detector and the Live Detection (in the upper right corner of the page) are enabled by default. When liveness detection is selected the operation will only succeed if the sample data comes from a live recording.
Now to the samples preview box. Every recording is shown in the box below the buttons. New samples - either images or recordings - are added from the left to the samples already recorded. If space runs out a scroll bar is shown below the samples. If you use the right mouse button in the preview box a context menu Clear all appears. You can select one sample with the left mouse button or several by using CTRL+Left Button. The menu turning up on the right mouse button while one or more samples are selected are Save as, Delete and also Clear all. Thus you can remove single samples you aren't satisfied with and don't need to re-record a whole set.