Showing papers by "Azriel Rosenfeld published in 1997"
TL;DR: A new theory of the Gestalt law of good continuation is proposed, in this theory perceptual processes are modeled by an exponential pyramid algorithm and they contradict prior models.
69 citations
18 Aug 1997
TL;DR: An approach to segmenting strokes into stylistically meaningful segments and establishing a local correspondence between a questioned signature and a reference signature is presented to enable the analysis and comparison of stroke features and shows promise for extension to the identification of skilled forgeries.
Abstract: Progress on the problem of signature verification has advanced more rapidly in online applications than offline applications, in part because information which can easily be recorded in online environments, such as pen position and velocity, is lost in static offline data. In offline applications, valuable information which can be used to discriminate between genuine and forged signatures is embedded at the stroke level. We present an approach to segmenting strokes into stylistically meaningful segments and establish a local correspondence between a questioned signature and a reference signature to enable the analysis and comparison of stroke features. Questioned signatures which do not conform to the reference signature are identified as random forgeries. Most simple forgeries can also be identified, as they do not conform to the reference signature's invariant properties such as connections between letters. Since we have access to both local and global information, our approach also shows promise for extension to the identification of skilled forgeries.
55 citations
18 Aug 1997
TL;DR: A taxonomy of functional document components is defined and it is shown how functional descriptions can be used to reverse-engineer the intentions of the author, to navigate in document space, and to provide important contextual information to aid in interpretation.
Abstract: The purpose of a document is to facilitate the transfer of information from its author to its readers. It is the author's job to design the document so that the information it contains can be interpreted accurately and efficiently. To do this, the author can make use of a set of stylistic tools. In this paper, we introduce the concept of document functionality, which attempts to describe the roles of documents and their components in the process of transferring information. A functional description of a document provides insight into the type of the document, into its intended uses, and into strategies for automatic document interpretation and retrieval. To demonstrate these ideas, we define a taxonomy of functional document components and show how functional descriptions can be used to reverse-engineer the intentions of the author, to navigate in document space, and to provide important contextual information to aid in interpretation.
27 citations
TL;DR: A new concept of a “digitally continuous” deformation of a digital curve is introduced, under which the regions inside and outside the curve remain disjoint is digitally continuous and does preserve topology.
26 citations
TL;DR: The geometry of image formation is analyzed and it is shown that human vision appears to involve a new branch of geometry whose properties are quite different from the properties of traditional geometries.
24 citations
TL;DR: A bibliography of nearly 2150 references related to computer vision and image analysis, arranged by subject matter, is presented, covering topics including computational techniques; feature detection and segmentation; image and scene analysis; and motion.
23 citations
TL;DR: A multilevel Markov Random Field (MRF) energy environment has been developed that simultaneously performs delineation, representation and classification of two-dimensional objects by using a global optimization technique and its use of a multipolar representation allows it to handle partially occluded objects.
15 citations
13 citations
01 May 1997
TL;DR: It is shown that simple geometric and colorimetric methods can measure stem flaccidity and leaf pallor, which can indicate the thirstiness of a plant.
Abstract: How can we distinguish images of a plant that needs watering from images of the plant in good condition? We show that simple geometric and colorimetric methods can measure stem flaccidity and leaf pallor, which can indicate the thirstiness of a plant.
10 citations
TL;DR: It is demonstrated that the MP model-a system of self-organizing active particles—has a number of advantages over previous models, both parametric active models (“snakes”) and implicit (contour evolution) models.
10 citations
TL;DR: This work gives a closed-form characterization of the clusters that result from TDK-based growth processes: specifically, it is shown that TDKs give rise to convex octagons.
20 Oct 1997
TL;DR: In this article, the authors introduce a class of planar arcs and curves, called tame arcs, which are general enough to describe the boundaries of real objects, and motivate their definition by the fact that they can be obtained by digitizing continuous supported arcs.
Abstract: We introduce a class of planar arcs and curves, called tame arcs, which is general enough to describe the boundaries of planar real objects. A tame arc can have smooth parts as well as sharp corners; thus a polygonal arc is tame. On the other hand, this class of arcs is restrictive enough to rule out pathological arcs which have infinitely many inflections or which turn infinitely often: a tame arc can have only finitely many inflections, and its total absolute turn must be finite. In order to relate boundary properties of discrete objects obtained by segmenting digital images to the corresponding properties of their continuous originals, the theory of tame arcs is based on concepts that can be directly transferred from the continuous to the discrete domain. A tame arc is composed of a finite number of supported arcs. We define supported digital arcs and motivate their definition by the fact that hey can be obtained by digitizing continuous supported arcs. Every digital arc is tame, since it contains a finite number of points, and therefore it can be decomposed into a finite number of supported digital arcs.
TL;DR: It is shown that the points of f visible from P subtend an angular sector at P and that there exist finite sets of points P from which all of f is visible, but that this need not be true if the points are required to lie on f.
01 Sep 1997
TL;DR: MIST was applied and demonstrated to be useful for such problems as conceptual interpretation of natural scences, non-structural and structural texture description and identification, detection of blasting caps in X-ray images of airport luggage, and target detection in SAR images.
Abstract: : The underlying motivation for this research is that vision systems need learning capabilities for handling problems for which algorithmic solutions are unknown or difficult to obtain. In this context, we have conducted research on a wide range of vision problems that can benefit from machine learning. We have developed a general methodology for this purpose, called MIST, that supports multilevel image sampling, transformation, learning and interpretation. MIST is based on the application of symbolic or multistrategy learning methods (the latter one integrates symbolic and neural net learning) for creating visual concept descriptions. MIST was applied and demonstrated to be useful for such problems as conceptual interpretation of natural scences, non-structural and structural texture description and identification, detection of blasting caps in X-ray images of airport luggage, and target detection in SAR images. We have also obtained important results in the areas of action recognition in video image sequences, visual memories, estimation of environment properties from sampling, and bisight head control. The obtained results have demonstrated a significant promise and usefulness of the efforts to apply modern machine learning methods to problems of computer vision.