## Computation of segment Likelihood functions using PPT

In (14.2), the PDFs are the segment PDFs conditioned on knowing the segment sub-class (the segment sub-classes are assumed to be fixed for each segmentation ). These are obtained using the PPT (equation 2.2) and a feature transformation specific to sub-class on a segment of length base segments:

 (14.4)

where is the feature used for a segment of size and sub-class , is the PDF of that feature assuming sub-class , and is the PDF of that feature under the reference hypothesis. This calculation has been described for a range of different features (See chapters 4 through 10). The MR-HMM requires a large amount of front-end processing to calculate all the necessary features and PDFs for all segments (seen in Figure 14.1 Available segments") assuming each possible sub-class.

Baggenstoss 2017-05-19