[University of Szeged]
Institute of Informatics >>>
Department of Image Processing and Computer Graphics >>>
Image Processing on Projections and Its Applications for Image Reconstruction
Reconstruction tomography produces 2-dimensional cross-sections of 3-dimensional objects from their projections taken from several directions. Depending on the reconstruction task, projections can be acquisited by X-rays, gamma-rays, etc. In the most common situation radiation is generated outside the object (CT), in other scenarios the object itself emits gamma-rays (SPECT, PET). In image reconstruction the task is – roughly speaking – to backproject the sinogram consisting of the projections of the original image. This is usually performed by filtered backprojection (FBP) or algebraic iterative methods (ART, SART, SIRT). In practice, projections are taken from discrete angles, and they are noisy, too. The aim of this project is to improve the well-known methods of continuous and discrete tomography, and especially the followings:
- study of image processing methods, that can be applied directly on the projections to improve reconstruction quality (active contours, segmentation, edge-detection, denoising, etc.)
- incremental reconstruction by identifying important projections angles
- improving techniques to measure the quality of the reconstructed images (similarity to model image, statistical features, smoothness, etc.)
- determination of attenuation coefficients from the sinogram for certain classes of images
- developing efficient discrete image reconstruction methods of novel types, based on parallel processing using GPUs where possible
- László Varga, Péter Balázs, and Antal Nagy. Projection selection dependency in binary tomography. Acta Cybernetica, 20:167-187, 2011.
- László Varga, Péter Balázs, and Antal Nagy. Direction-dependency of a binary tomographic reconstruction algorithm. In Proceedings of International Symposium on Computational Modeling of Objects Represented in Images, volume 6026 of Lecture Notes in Computer Science, Buffalo, USA, pages 242-253, May 2010. Springer Verlag.
- László Varga, Péter Balázs, and and Antal Nagy. Projection Selection Algorithms for Discrete Tomography. In J. Blanc-Talon, editor, Proceedings of International Conference on Advanced Concepts for Intelligent Vision Systems, volume 6474 of Lecture Notes in Computer Science, Sydney, Australia, pages 390-401, 2010. Springer Verlag.
- László Varga, Péter Balázs, and Antal Nagy. Direction-dependency of binary tomographic reconstruction algorithms. Graphical Models, 73:365-375, November 2011.
- Laszlo Varga, Peter Balazs, and Antal Nagy. An energy minimization reconstruction algorithm for multivalued discrete tomography. In Joao Manuel R.S. Tavares and Jorge R.M. Natal, editors, Proceedings of the International Symposium on Computational Modeling of Objects Represented in Images, Rome, Italy, pages 179-185, September 2012. Taylor & Francis.
- Peter Balazs and Kees Joost Batenburg. A central reconstruction based strategy for selecting projection angles in binary tomography. In Aurelio Campilho and Mohamed Kamel, editors, Proceedings of the International Conference on Image Analysis and Recognition, volume 7325 of Lecture Notes in Computer Science, Aveiro, Portugal, pages 382-391, June 2012. Springer Verlag.