Performs a liveness detection on the given samples, see Face Liveness Detection.
[OperationContract]
[FaultContract(typeof(BioIDWebServiceFault)]
bool LivenessDetection(Sample[] samples, out string messages);
Returns true when the given samples are undoubtedly determined to be live data;
false otherwise, or when errors occurred (see messages for details).
This method just performs a liveness detection (currently supported traits are face and periocular). The method will only succeed, when it can undoubtedly determine that the given data is live data. In case that the live detection for the face trait succeeds, the degree of the head rotation between two subsequent images is reported with the returned messages XML-string.
Internally this operation performs a QualityCheck (in BioID ExtractTokenData mode) for all submitted samples before they are forwarded to the liveness detection. Therefore you might get results from these operations as well together with the liveness detection results.
This API has a fault contract of type BioIDWebServiceFault which is used for fatal errors like invalid arguments or missing service, etc. Messages, even error messages, generated by the verification procedure are reported via the messages output value, which contains an XML string according to the BWSMessages schema namespace.
The messages output XML string might contain operation specific errors as follows:
The messages output XML string might also contain errors for the individual samples. Many of the errors can result from the initial quality-check that is performed before anything else is done. Please refer to the QualityCheck method for a list of sample errors that might have been generated by the quality-check.
Additionally the following errors can occur. With any of theses errors the sample is marked as unsuitable and is not considered in the liveness detection process: