Presenter

Mr. Tim Bruylants [Email]

Abstract

Medical and holographic imaging modalities produce large datasets that require efficient compression mechanisms for storage and transmission. This PhD dissertation proposes state-of-the-art technology extensions for JPEG coding standards to improve their performance in the aforementioned application domains.

Modern hospitals rely heavily on volumetric images, such as produced by CT and MRI scanners. In fact, the completely digitized medical work flow, the improved imaging scanner technologies and the importance of volumetric image data sets have led to an exponentially increasing amount of data, raising the necessity for more efficient compression techniques with support for progressive quality and resolution scalability. For this type of imagery, JP3D a volumetric extension of the JPEG 2000 standard was created and, in addition, JP3D improvements, being alternative wavelet filters, directional wavelets and an intra-band prediction mode, were proposed and their applicability was evaluated.

Holographic imaging, essentially recording interference patterns, is a new imaging modality that is currently primarily used in microscopy and non-destructive testing. Besides their high-resolution nature, holograms exhibit atypical frequency distribution characteristics that lead to inferior compression efficiency when deploying classical image compression techniques. This dissertation proposes a solution that exploits directional wavelet filters with advanced packet decomposition modes in combination with a JPEG 2000 encoding engine. This compression engine significantly outperforms the current state-of-the-art in compression performance.

Finally, this work also involved various contributions to other JPEG standardization activities. First of all, a subjective quality evaluation of JPEG XR was performed, which was afterwards also used to validate the proposed JP3D extensions of this work. Secondly, this dissertation contributes to two JPEG Systems standards, which were initiated with the main purpose of consolidating shared features over different standards. And finally, for the upcoming JPEG XT standard, this dissertation discusses the creation of Part 9 of the standard that provides Alpha Channel Coding functionality.