Affiliations: [a] Computer Department, Federal University of São Carlos, São Carlos, SP, Brazil | [b] Department of Chemical Engineering, Federal University of São Carlos, São Carlos, SP, Brazil
Correspondence:
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Corresponding author: Dr. N.D.A. Mascarenhas, Computer Department, Federal University of São Carlos, Rod. Washington Luis, km 235 CEP 13565-905, São Carlos, SP, Brazil. E-mail: [email protected].
Abstract: Dynamic magnetic resonance imaging is an emerging technique for studying speech production. Vocal tract image sequences acquired during the speech of words or phonemes allow the identification of shapes taken by the vocal tract during speech production. However, there is no prior knowledge about the spatial and temporal resolution requirements, which are expected to vary depending on the speech task. Available approaches try to enhance resolution by empowering the acquisition devices. However, there are several cost and hardware limitations. In this paper, we propose an alternative approach to enhance spatio-temporal resolution using only digital image processing techniques. We use a previous non-rigid image registration method to identify displacements and deformations among the observed images. Based on a motion compensated interpolation approach, temporal resolution is increased by generating intermediate images which are coherent with the movement present in the observed sequence. Moreover, a MAP-MRF super-resolution image reconstruction approach is used to increase spatial resolution of the whole sequence. Results indicate the effectiveness of our approach.
