Visualization & Interaction
Understanding complex data sets, such as three dimensional images of the human body, can be improved if you can both see the organs in three dimensions and feel them. The first is called visualisation and the second haptics. We develop new, fast, mathematical methods here. One application is surgery planning.
Modern imaging techniques provide an increasing amount of high dimensional and high-resolution image data that need to be analyzed and interpreted. As a consequence, efficient ways of exploring these images are needed. Vi2 has a large focus on perceptualization, in particular effective ways to combine visualization and haptic rendering, and we often favor interactive techniques over completely automatic techniques for exploration and segmentation of medical and biological data. We develop interactive, haptics-supported, 3D stereo display techniques for segmentation, continually extending our public domain segmentation tool WISH, which is a toolbox for interactive exploration of complex medical image volumes for diagnosis and treatment planning. Tools developed within this project have found use in many applications, e.g.,
- craniomaxillofacial surgery planning.
- visualization of 3D protein images acquired by molecular electron tomography.
- analysis of MR images of the human brain.
- analysis of CT images of fractured wrists.
While most of our haptic usage relies on conventional hardware, we are also developing new haptics hardware that is more suitable to surgery planning than a device that has only one point-of-contact with a virtual object. The long term goal is a haptic glove that gives force feedback to all fingers. But to date we have developed on joint for a glove based on piezotechnology and demonstrated that is can be used to pick up and position objects and can accurately reproduce object stiffness, which will be particularly useful in manipulation of soft tissue in surgery.
Computer graphics is increasingly being used to create realistic images of 3D objects for applications in entertainment, (animated films, games), commerce (showing 3D images of products on the web), industrial design and medicine. For the images to look realistic high quality shading and surface texture and topology rendering is necessary. A proper understanding of the mathematics behind the algorithms can make a big difference in rendering quality as well as speed. We have over the years re-examined several of the established algorithms and found new mathematical ways of simplifying the expressions and increasing the implementation speeds without sacrificing image quality. We have also invented a number of completely new algorithms.
Mobile devices have recently seen an enormous advancement in their computational power with many exciting and promising pieces of technology available at the same time such as mobile graphics processing, spatial positioning, and access to geo-spatial databases. An ongoing research project on "ubiquitous visualization" deals with mobile visualization of spatial data in indoor and outdoor environments.