Comparison of Local Feature Detectors and Descriptors for Visual Object Categorization

Local features are used in many computer vision tasks including visual object categorization, content-based image retrieval and object recognition to mention a few. Local features are points, blobs or regions in images that are extracted using a local feature detector. To make use of extracted local features the localized interest points are described using a local feature descriptor. A descriptor histogram vector is a compact representation of an image and can be used for searching and matching images in databases. In this thesis the performance of local feature detectors and descriptors is evaluated for object class detection task. Features are extracted from image samples belonging to several object classes. Matching features are then searched using random image pairs of a same class. The goal of this thesis is to find out what are the best detector and descriptor methods for such task in terms of detector repeatability and descriptor matching rate.

ZigBee-verkot ja evaluointilaitteen suunnittelu

In this thesis a closer look at ZigBee wireless network protocol was made and a ZigBee evaluation device was designed and built for testing it. ZigBee is a digital wireless network technology published in 2004, which was developed for wireless control and automation systems. It is based on the IEEE 802.15.4-2003 standard, and its aim was to create a reliable wireless networking protocol with secure data transmissions, low power consumption and low manufacturing costs. The low power consumption requirement has also led to a slow data rate and a short range, but in a ZigBee network individual network devices can route messages to each other, so short range is not a problem. In automation and control systems a fast data rate is not usually an important requirement either. ZigBee network can form automatically and one ZigBee network can theoretically include thousands of devices, all of which can communicate with each other. ZigBee network is also self-healing, so an individual device dropping out of the network, like breaking down, does not affect functionality of the network. Evaluation device was designed and implemented in four different versions, which were tested with six different antenna designs. All antennas were tested at a range of 100 meters in an open terrain using two different frequencies and transmission powers. Also a range test was performed for selected antennas using transmission power of 4,5 dBm, which was maximum power of the ZigBee chip used in the evaluation device. Range test resulted in a measured range of several hundred meters, which can be considered as a good result for a short-range technology.

Viva la mamma : eli Oopperan ihanuus ja kurjuus : kaksinäytöksinen ooppera = eller Operans härlighet och elände : opera i två akter

Sibelius-Akatemian konserttisarja 12.2.1981.

[Kanteletar I:32] : [kanteleelle ja orkesterille]

Soitinnus: kantele, orkesteri.

Kolme kontrastia

Soitinnus: viulu, huilu, klarinetti, sello, piano.

Yhteiskunta ennen sosiologiaa

Kirjallisuusarvostelu

Globaalin regressiomallin lokalisointi homogeenisissa ositteissa

Seloste artikkelista: Segmentation of model localization subareas by Getis statistics / Minna Räty & Annika Kangas. - Julkaisussa: Silva Fennica 44 (2010) : 2, s. 303-317.

Valokuvan voimauttavat mahdollisuudet

Kirjallisuusarvostelu

Pahuuden ytimessä

Kirjallisuusarvostelu

Menetelmäpohdintoja ja -kokemuksia

Kirjallisuusarvostelu

Seksismi ja syrjintä

Kirjallisuusarvostelu