Národní úložiště šedé literatury Nalezeno 3 záznamů.  Hledání trvalo 0.00 vteřin. 
Fusing image and non-grid-like data for object segmentation
Repka, Samuel ; Nosko, Svetozár (oponent) ; Zemčík, Pavel (vedoucí práce)
Quite often, a phenomenon of interest can described by more than one data source. For example, a car's appearance shows its colour and brand, but not its engine status. However, other data sources do provide us with this information, be it a sound or mere touch. Such data source is often referred to as a modality. While using a single data source to extract the needed information may be sufficient, the addition of more modalities can be beneficial, because of their complementary nature. This data fusion, however, may be a quite challenging process. Different kinds of data have different properties, structures and various challenges connected to them. A plethora of different methods has been proposed, but usually, the methods are very data-dependent. This thesis presents a new approach to the fusion of two modalities, primarily for the purpose of image segmentation. One of the modalities is image, and the second one is any non-grid-like modality. The method uses a graph to jointly represent both modalities, aiming to capture the intra and inter-modalities relationships as accurately as possible. The graph is then processed, producing a graph with fused data, or a direct segmentation. The proposed method was evaluated on two datasets (from the fields of mineralogy and timber processing) and compared to another solution, showing both the potential and limitations of the method. In case of the mineralogy dataset, the results are very encouraging, showing that the method is capable of data fusion, even outperforming a contemporary method. In case of the timber dataset, the results were not as conclusive, as the method failed to improve the results when compared to a baseline solution, which may have been caused by a challenging dataset.
Photometric Stereo Processing for Microscopy
Repka, Samuel ; Hradiš, Michal (oponent) ; Zemčík, Pavel (vedoucí práce)
This paper proposed a method of 3D reconstruction of scanning electron microscope (SEM) specimen. The aim is to explore the possibilities of topography reconstruction of microscopic samples, as well as to attempt to solve the task using tools already available on conventional scanning electron microscopes. The proposed solution uses images from a four-segment backscattered electrons detector as an input to the photometric stereo algorithm. This algorithm exploits the fact that the brightness of the image point is dependent on the inclination of the sample surface. Reflectance maps are used to estimate the inclination in each pixel, creating a map of normal vectors. The map is then used for topography reconstruction. A novel technique for reflectance map estimation is proposed. This method is applied to tin samples to remove the sample's atomic number effects. The fact that all data are acquired simultaneously allows for fast reconstruction. Usage of already available and widespread tools eliminates a need for specialized equipment such as Atomic Force Microscopes.
Photometric Stereo Processing for Microscopy
Repka, Samuel ; Hradiš, Michal (oponent) ; Zemčík, Pavel (vedoucí práce)
This paper proposed a method of 3D reconstruction of scanning electron microscope (SEM) specimen. The aim is to explore the possibilities of topography reconstruction of microscopic samples, as well as to attempt to solve the task using tools already available on conventional scanning electron microscopes. The proposed solution uses images from a four-segment backscattered electrons detector as an input to the photometric stereo algorithm. This algorithm exploits the fact that the brightness of the image point is dependent on the inclination of the sample surface. Reflectance maps are used to estimate the inclination in each pixel, creating a map of normal vectors. The map is then used for topography reconstruction. A novel technique for reflectance map estimation is proposed. This method is applied to tin samples to remove the sample's atomic number effects. The fact that all data are acquired simultaneously allows for fast reconstruction. Usage of already available and widespread tools eliminates a need for specialized equipment such as Atomic Force Microscopes.

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