We propose a new method to measure torsional eye movements from videos taken of the eye. In this method, we track iris features that have been identified as Maximally Stable Volumes. These features, which are stable over time, are dark regions with bright borders that are steep in intensity. The advantage of Maximally Stable Volumes is that they are robust to nonuniform illumination and to larg...

We study the existence and computation of extremal solutions of a system of inequations defined over lattices. Using the Knaster-Tarski fixed point theorem, we obtain sufficient conditions for the existence of supremal as well as infimal solution of a given system of inequations. Iterative techniques are presented for the computation of the extremal solutions whenever they exist, and conditions...

Feature or interest points typically use information aggregation in 2D patches which does not remain stable at object boundaries when there is object motion against a significantly varying background. Level or iso-intensity curves are much more stable under such conditions, especially the longer ones. In this paper, we identify stable portions on long iso-curves and detect corners on them. Furt...

We study the existence and computation of extremal solutions of a system of inequations de ned over lattices. Using the Knaster-Tarski xed point theorem, we obtain su cient conditions for the existence of supremal as well as in mal solution of a given system of inequations. Iterative techniques are presented for the computation of the extremal solutions whenever they exist, and conditions under...

Text detection and recognition is a hot topic for researchers in the field of image processing. It gives attention to Content based Image Retrieval (CBIR) community in order to fill the semantic gap between low level and high level features. Several methods have been developed for text detection and extraction that achieve reasonable accuracy for natural scene text (camera images) as well as mu...

In complex aeronautical and space engineering systems, conventional sensors used for environment perception fail to determine the orientation because of the influences of the special environments, wherein geomagnetic fields are exceptional and the Global Positioning System is unavailable. This paper presents a fisheye-lens-based visual sun compass that is efficient in determining orientation in...

The invariant feature detectors are essential components in many computer vision applications, such as tracking, simultaneous localization and mapping (SLAM), image search, machine vision, object recognition, 3D reconstruction from multiple images, augmented reality, stereo vision, and others. However, it is very challenging to detect high quality features while maintaining a low computational ...

Automatic image registration is a vital yet challenging task, particularly for remote sensing images. A fully automatic registration approach which is accurate, robust, and fast is required. The registration process is divided into six main steps: feature detection, feature extraction, feature matching, outlier detection and removal, transform model estimation and resampling. In the feature det...

Unmanned Aerial Systems (UAS) are now capable of gathering high-resolution data, therefore, landslides can be explored in detail at larger scales. In this research, 132 aerial photographs were captured, and 85,456 features were detected and matched automatically using UAS photogrammetry. The root mean square (RMS) values of the image coordinates of the Ground Control Points (GPCs) varied from 0...

This paper introduces a novel boundary detection framework finding the most stable region boundaries in grayscale images. In contrast to common detection algorithms as Canny, which only analyze local discontinuities in image brightness our method also integrates mid-level information by analyzing regions that support the local gradient magnitudes. We build a component tree where every node cont...