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Content Based Photo Search
Bařinka, Radek ; Přibyl, Bronislav (referee) ; Španěl, Michal (advisor)
This thesis deals with the problematics of searching of photographs by the content and existing applications dealing with this subject. The aim is the local working application for searching of photographs by the content given by a pattern. The solution consists of the simple graphical interface, the support of saving data and the reading of data from the transferable local database. The application searches the photographs of a given set that are similar to the given pattern. The results are visually depicted to the user. Feature extraction and detection by photo content is solved by means SURF algorithm, visual vocabulary created by method k-means and a description of photography as a bag of words. In addition,the searching of photographs by cosine similarity of vectors enriched with the independent calculation of homography and the selection of regions searched in an example photography. At the end of the technical report the results of testing are presented.
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3D Mapping of Outdoor Environment
Janalík, Radim ; Orság, Filip (referee) ; Herman, David (advisor)
This thesis deals with 3D map building of outdoor environment using laser rangefinders. Sensor measurements are transformed to the points and are aggregated to an internal model with respect to the current robot's position. From these points, a triangular mesh is created using Delaunay triangulation algorithm. The memory requirements for storing the internal model are reduced by mesh decimation algorithm. The presented method builds the map incrementally in real time. Several experiments have been conducted to verify the presented approach.
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Photon Mapping
Nečas, Ondřej ; Španěl, Michal (referee) ; Herout, Adam (advisor)
This thesis deals with practical implementation of photon mapping algorithm. To achieve better results some basic and some more advanced methods of global illumination has been examined. These time demanding algorithms are often practically unusable and their further optimization is necessary. Optimized ray tracer is essential for practical implementation. Computing diffuse interreflection by Monte Carlo sampling is also very time demanding operation. Therefore it is appropriate to use it along with proper interpolation.
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Automatic Photography Categorization
Matuszek, Martin ; Beran, Vítězslav (referee) ; Španěl, Michal (advisor)
This thesis deal with choosing methods, design and implementation of application, which is able of automatic categorization photos based on its content into predetermined groups. Main steps of categorization are described in greater detail. Finding and description of interesting points in image is implemented using SURF, creation of visual dictionary by k-means, mapping on the words through kd-tree structure. Own evaluation is made for categorization. It is described, how the selected steps were implemented with OpenCV and Qt libraries. And the results of runs of application with different settings are shown. And efforts to improve outcome, when the application can categorize right, but success is variable.
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3D Spatial Indexing of Objects
Drbal, Miroslav ; Dvořák, Radim (referee) ; Orság, Filip (advisor)
This diploma thesis defines the term indexing and in preamble are discussed known indexing algorithms and difference between indexing static and moving objects. The practical part of this diploma thesis is aimed to designing and implementing of indexing algorithm for open source application MaNGOS with respect to generic design pattern and effectiveness of spatial search queries for selection of the objects given properties in the specified area. At the end I present and discuss reached results.
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Distributed Ray Tracing in Reasonable Time
Slovák, Radek ; Polok, Lukáš (referee) ; Herout, Adam (advisor)
This thesis deals with the method of distributed ray tracing focusing on optimalization of this method. The method uses simulation of some attributes of light by distributing rays of lights and it produces high quality and partly realistic images. The price for realitic effects is the high computational complexity of the method. The thesis analysis the theory connected with these aspects. A large part describes optimalizations of this method, i.e. searching for the nearest triangle intersection using kd-trees, quasi random sampling with faster convergence, the use of SSE instruction set and fast ray - triangle intersection. These optimalizations brought a noticable speed - up. The thesis includes description of implementation of these techniques. The implementation itself emphasises the practical usability including generating some advanced animations and universal description of objects.
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K-Nearest Neighbour Search Methods
Cigánik, Marek ; Bartík, Vladimír (referee) ; Burgetová, Ivana (advisor)
The thesis describes the basic concept of the K-nearest neighbors algorithm and its connection with the human concept of object similarity. Concepts and key ideas such as the distance function or the curse of dimensionality are elaborated. The work includes a detailed description of the methods KD-Tree, Spherical Tree, Locality-Sensitive Hashing, Random Projection Tree and families of algorithms based on the nearest neighbor graph. An explanation of the idea with visualizations, pseudocodes and asymptotic complexities is provided for each method. The methods were subjected to experiments and both basic and more advanced metrics were measured and appropriate use cases for individual methods were evaluated.
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Acceleration of Ray-Casting for CSG scenes
Zajíček, Petr ; Wilkie, Alexander (advisor) ; Křivánek, Jaroslav (referee)
Ray tracing acceleration methods are usually applied to scenes defined by triangle meshes.These scenes contain a large number of triangles. In contrast, CSG scenes contain orders of magnitude less more complex primitives primitives. In this thesis we will present the Operation KD-tree. This acceleration method applies the KD-tree --- modern acceleration method developed for triangle meshes --- directly to the CSG scene. This is done on the premise, that the huge reduction in primitive count will yield enhanced performance, when rendering a scene using CSG instead of triangle meshes.
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