This paper presents a method for extracting distinctive invariant features from images that can be used to perform reliable matching between different views of an object or scene. The features are invariant to image scale and rotation, and are shown to provide robust matching across a substantial range of affine distortion, change in 3D viewpoint, addition of noise, and change in illumination. The features are highly distinctive, in the sense that a single feature can be correctly matched with high probability against a large database of features from many images. This paper also describes an approach to using these features for object recognition. The recognition proceeds by matching individual features to a database of features from known objects using a fast nearest-neighbor algorithm, followed by a Hough transform to identify clusters belonging to a single object, and finally performing verification through least-squares solution for consistent pose parameters. This approach to recognition can robustly identify objects among clutter and occlusion while achieving near real-time performance.

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Distinctive Image Features from Scale-Invariant Keypoints

The increasing volume of data in modern business and science calls for more complex and sophisticated tools. Although advances in data mining technology have made extensive data collection much easier, it's still always evolving and there is a constant need for new techniques and tools that can help us transform this data into useful information and knowledge. Since the previous edition's publication, great advances have been made in the field of data mining. Not only does the third of edition of Data Mining: Concepts and Techniques continue the tradition of equipping you with an understanding and application of the theory and practice of discovering patterns hidden in large data sets, it also focuses on new, important topics in the field: data warehouses and data cube technology, mining stream, mining social networks, and mining spatial, multimedia and other complex data. Each chapter is a stand-alone guide to a critical topic, presenting proven algorithms and sound implementations ready to be used directly or with strategic modification against live data. This is the resource you need if you want to apply today's most powerful data mining techniques to meet real business challenges. * Presents dozens of algorithms and implementation examples, all in pseudo-code and suitable for use in real-world, large-scale data mining projects. * Addresses advanced topics such as mining object-relational databases, spatial databases, multimedia databases, time-series databases, text databases, the World Wide Web, and applications in several fields. *Provides a comprehensive, practical look at the concepts and techniques you need to get the most out of real business data

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Data Mining: Concepts and Techniques

Computer vision applications have come to rely increasingly on superpixels in recent years, but it is not always clear what constitutes a good superpixel algorithm. In an effort to understand the benefits and drawbacks of existing methods, we empirically compare five state-of-the-art superpixel algorithms for their ability to adhere to image boundaries, speed, memory efficiency, and their impact on segmentation performance. We then introduce a new superpixel algorithm, simple linear iterative clustering (SLIC), which adapts a k-means clustering approach to efficiently generate superpixels. Despite its simplicity, SLIC adheres to boundaries as well as or better than previous methods. At the same time, it is faster and more memory efficient, improves segmentation performance, and is straightforward to extend to supervoxel generation.

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SLIC Superpixels Compared to State-of-the-Art Superpixel Methods

The k-means method is a widely used clustering technique that seeks to minimize the average squared distance between points in the same cluster. Although it offers no accuracy guarantees, its simplicity and speed are very appealing in practice. By augmenting k-means with a very simple, randomized seeding technique, we obtain an algorithm that is Θ(logk)-competitive with the optimal clustering. Preliminary experiments show that our augmentation improves both the speed and the accuracy of k-means, often quite dramatically.

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k-means++: the advantages of careful seeding

http://library.utia.cas.cz/prace/20030125.pdf

Image registration methods: a survey

This paper addresses the importance of a maximum entropy formulation for the extraction of content from a single picture element in a remotely sensed image. Most conventional classifiers assume a winner take all procedure in assigning classes to a pixel whereas in general it is the case that there exists more than one class within the picture element. There have been attempts to perform spectral unmixing using variants of least-squares techniques, but these suffer from conceptual and numerical problems which include the possibility that negative fractions of ground cover classes may be returned by the procedure. In contrast, a maximum entropy (MAXENT) based approach for sub-pixel content extraction possesses the useful information theoretic property of not assuming more information than is given, while automatically guaranteeing positive fractions. In this paper we apply MAXENT to obtain the fractions of ground cover classes present in a pixel and show its clear numerical superiority over conventional methods. The optimality of this method stems from the combinatorial properties of the information theoretic entropy.© (1997) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Spectral unmixing of remotely sensed imagery using maximum entropy

In the late 1990s, NASA will launch a series of satellites to study the Earth as a dynamic system. The enormous size and complexity of the resulting data holdings pose several challenges and promise to test the limits of practical AI techniques.

Mission to Planet Earth: AI views the world

We propose a novel framework for associating multi-target trajectories across multiple non-overlapping views (cameras) by constructing an invariant model per each observed target. Ideally, these models represent the targets in a unique manner. The models are constructed by generating synthetic images that simulate how targets would be seen from different viewpoints. Our framework does not require any training or other supervised phases. Also, we do not make use of spatiotemporal coordinates of trajectories, i.e., our framework seamlessly works with both overlapping and non-overlapping field-of-views (FOVs) as well as widely separated ones. Also, contrary to many other related works, we do not try to estimate the relationship between cameras that tends to be error prone in environments like airports or supermarkets where targets wander about different areas, stop at times, or turn back to their starting location. We show the results obtained by our framework on a rather challenging dataset. Also, we propose a black-box approach based on Support Vector Machine (SVM) for fusing multiple pertinent algorithms and demonstrate the added value of our framework with respect to some basic techniques.

A framework for inter-camera association of multi-target trajectories by invariant target models

Assuming that approximate registration is given within a few pixels by a systematic correction system, we develop automatic image registration methods for multi-sensor data with the goal of achieving sub-pixel accuracy. Automatic image registration is usually defined by three steps; feature extraction, feature matching, and data resampling or fusion. Our previous work focused on image correlation methods based on the use of different features. In this paper, we study different feature matching techniques and present five algorithms where the features are either original gray levels or wavelet-like features, and the feature matching is based on gradient descent optimization, statistical robust matching, and mutual information. These algorithms are tested and compared on several multi-sensor datasets covering one of the EOS Core Sites, the Konza Prairie in Kansas, from four different sensors: IKONOS (4m), Landsat-7/ETM+ (30m), MODIS (500m), and SeaWIFS (1000m).

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Multi-Sensor Registration of Earth Remotely Sensed Imagery

In this article we introduce a blockage-detection method, which manages to detect a large set of blockage positions in pawn endgames, with practically no additional overhead. By examining different elements of the pawn structure, the method checks whether the Pawns form a blockage which prevents the King from penetrating into the opponent's camp. It then checks several criteria to find out whether the blockage is permanent.

Nathan S. Netanyahu

Papers

Spectral unmixing of remotely sensed imagery using maximum entropy

Mission to Planet Earth: AI views the world

A framework for inter-camera association of multi-target trajectories by invariant target models

Multi-Sensor Registration of Earth Remotely Sensed Imagery

Blockage detection in pawn endings