Detecting a biometric event in a noisy signal

Apparatus for detecting a biometric event in an input signal, the apparatus comprising:

• a principal component analysis PCA unit configured to perform PCA on samples of a plurality of model signals to generate a transformation matrix having more informative components and less informative components, each of the model signals comprising a known signal which includes the biometric event to be detected, and to reduce a dimensionality of the transformation matrix by discarding one or more of the more informative components;
• a sample transformation unit configured to transform a plurality of samples of the input signal using the reduced dimensionality transformation matrix;
• a probability determining unit configured to determine a probability that the biometric event is present in the plurality of samples of the input signal, by calculating a predefined probability function for the transformed samples;
• and
• a biometric event detecting unit configured to determine that the input signal includes the biometric event if the probability is higher than a threshold.

Apparatus for detecting a biometric event in an input signal, the apparatus comprising:

• a processing unit comprising one or more processors;
• and
• memory arranged to store computer program instructions which, when executed by the processing unit, cause the apparatus to:
• perform principal component analysis PCA on samples of a plurality of model signals to generate a transformation matrix having more informative components and less informative components, each of the model signals comprising a known signal which includes the biometric event to be detected;
• reduce a dimensionality of the transformation matrix by discarding one or more of the more informative components;
• transform a plurality of samples of the input signal using the reduced dimensionality transformation matrix;
• determine a probability that the biometric event is present in the plurality of samples of the input signal, by calculating a predefined probability function for the transformed samples;
• and
• determining that the input signal includes the biometric event if the probability is higher than a threshold.