A method of rapid semi-automatic segmentation of real-time magnetic resonance image (rMRI) data for parametric analysis of vocal tract shaping is described. Tissue boundaries are identified by finding pixel intensity thresholds along tract-normal gridlines. Airway contours are constrained with respect to a tract centerline defined as an optimal path over the graph of all intensity minima identified between the glottis and lips. The method allows for superimposition of reference boundaries to guide automatic segmentation of anatomical features which are poorly imaged using magnetic resonance -- dentition and the hard palate -- resulting in more accurate sagittal sections than those produced by fully automatic segmentation. We demonstrate the utility of the technique in the dynamic analysis of tongue shaping in Tamil liquid consonants.
Bibliographic reference. Proctor, Michael I. / Bone, Daniel / Katsamanis, Athanasios / Narayanan, Shrikanth S. (2010): "Rapid semi-automatic segmentation of real-time magnetic resonance images for parametric vocal tract analysis", In INTERSPEECH-2010, 1576-1579.