Coding of Medical Content

Scalable Lossless Coding of Dynamic Medical Data Using Compensated Multi-Dimensional Wavelet-Lifting:

Contact Person: Daniela Lanz, M.Sc.

This project focuses on scalable lossless coding of dynamic medical data. An efficient scalable representation of dynamic volume data from medical devices like Computed Tomography is very important for telemedicine applications. Thereby, lossless reconstruction is regulated by law and has to be guaranteed. Compensated Wavelet-Lifting combines scalability features and lossless reconstruction by only one processing step.

A wavelet transform (WT) decomposes a signal into a high- and lowpass subband. This allows for analysing the signal in multiple resolutions and provides an efficient coding of the volume by the energy compaction in the lowpass subband. Further, the quality of the lowpass subband can be increased by suitable approaches for motion compensation. By applying this coding scheme quality scalability as well as spatial and temporal scalability can be achieved. The block diagram above shows the single processing steps of 3-dimensional Wavelet-Lifting.


Coding High Resolution Video Data

Contact Person: Kristian Fischer, M.Sc.

Nowadays, more and more video data is provided in very high resolution. Media-services provider like Netflix or Amazon Prime are rapidly increasing their service of 4K videos. One 4K frame contains 3840×2160 pixels. Hence, the question arises how to transmit those enormous amounts of data to the end user.

In the past, it was shown that it is beneficial for scenarios with low bitrate, especially for videos with large resolution like 4K, to downscale the single 4K frames by half the size in each dimension before transmitting them. By doing so, the size of the video to transmit via the channel is only at full HD resolution (1920×1080 pixels). Therewith, coding artifacts can be reduced significantly. Naturally, the resolution of the arriving video has to be increased back to 4K resolution at the receiver side. For this purpose, several upscaling algorithm are evaluated to achieve the most appealing quality for the end user.