Showing papers in "Computer Graphics and Image Processing in 1978"

TL;DR: This paper presents a review of a variety of techniques for automatic threshold selection, including global, local, and dynamic methods, which have been proposed for automatic thresholds selection in image segmentation.

TL;DR: A general segmentation method which can be applied to many different types of scenes and the potential performance of other segmentation techniques on general scenes is discussed.

TL;DR: Algorithms for shape analysis are reviewed and classified under two criteria: whether they examine the boundary only or the whole area, and whether they describe the original picture in terms of scalar measurements or through structural descriptions.

TL;DR: In this paper, a general, parallel and hierarchical operator for picture processing is defined which at different levels can detect and describe structure as opposed to uniformity within local regions, whatever structure and uniformity may imply at a particular level.

TL;DR: In this paper, a system which models and calibrates the cameras and pairs the two images of a real-world point in the two pictures, either manually or automatically, was implemented.

TL;DR: The derivation of moment equations and a method of moment measurement are described and a threshold sequence and decision rules are developed and implemented in the matching of radar to optical images using a hierarchical search technique with the invariant moments as similarity measures.

TL;DR: A simple hardware encoder is proposed to handle this part of the task of computing 3 × 3 neighborhood functions of binary images, and in particular how this coding and encoder can be applied to the problem of boundary contour following, and suggest other areas of application.

TL;DR: A syntactic model for the generation of structured textures and for the discrimination of textures is proposed and a set of error-correcting tree automata is used as a texture discriminator.

TL;DR: In this article, a simple, highly efficient, and computationally stable algorithm is developed for the approximation of arbitrary planar curves by linear segments, which yields excellent results in economizing the number of line vectors required to represent curves on display within precisions specified by an error tolerance parameter.

TL;DR: An algorithm for detecting the dynamically changing surface of an organ such as the breathing lung or the beating heart from a time sequence of three-dimensional density distributions, making essential use of the temporal information is presented.

TL;DR: The approach presented here formulates the contour extraction problem as one of minimum cost tree searching as well as applying the Zigangirov-Jelinek (ZJ) stack algorithm to two real biomedical image processing problems.

TL;DR: In this paper, a new shape factor for objects in a binary picture is presented, which is based on the average distance between an interior picture point and the nearest boundary point and its properties are compared to the common shape factor P 2 4πA.

TL;DR: The three major components of dynamic scene analysis, namely segmentation, occlusion and the computation of three-dimensional information from images are discussed in depth in this paper, and detailed descriptions of the systems developed at The University of Texas are presented.

TL;DR: The probability density functions of Freeman codes are given under the assumption that the curve segment may be approximated by a line segment in a grid column (or grid row) to calculate the a priori probability of odd or even Freeman codes.

TL;DR: In this article, the dominant points of a digital curve are computed iteratively as the points of maximum global curvature, based on the local curvature of each point with respect to its immediate neighbors.

TL;DR: An algorithm to isolate a representation for a moving object of unknown form and size from a sequence of TV frames based on the assumption that a group of connected regions being jointly displaced in a systematic way from frame to frame without changing their relative positions is described.

TL;DR: It is shown that the one-dimensional isotonic regular and context-free array languages coincide and are closely related to the regular string languages.

TL;DR: Several methods of automatically determining twists in C 1 rectangular Coons patches are given, including two preprocessing schemes in which the twists are obtained from C° approximations based on positional and derivative information at the corners of the patches.

TL;DR: S symmetries are used as another — in addition to the average intensity values—global coarse picture parameter subregion characteristic, of a picture that has been regularly decomposed to a dimensionally reduced subset of a data-structure representation.

TL;DR: From a theoretical aspect the present grammar can tell the reason why global constraints need not be exploited by existing algorithms to understand pictures without hidden lines.

TL;DR: In this article, an iterative inversion algorithm is developed for a uniform cubic B-spline, which is extremely simple and fast, and it enables us interactively to find the best fitted curve by changing a curve knot continually on a CRT scope.

TL;DR: In this paper, the performance characteristics of Hough-like transforms for curve detection are presented, including homogeneity and packing in parameter space, sensitivity, estimation, and determination of required low-level measurement accuracies subject to cost constraints, and changes of the coordinate system to improve performance.

TL;DR: This paper presents a structural hypothesis about textures that are describable as recursively nested intensity regions and argues that gray level peaks should be used as textural primitives upon which recursion is based, and the use of several basic peak attributes is proposed for purposes of description.

TL;DR: It is contended that two stages can be isolated in the formal derivation of an operator; the obtaining of masks meaningful with respect to the phenomenon being sought, and the deriving of the procedural part.

TL;DR: The main purpose of this paper is to show that the constructed digital line possesses the chord property, and therefore is really straight.

TL;DR: In this article, the Barnhill-Gregory Boolean sum interpolant is used to construct a piecewise, interpolating C 1 surface through a set of arbitrarily spaced three-dimensional points {( x i, y i, z i ), i = 1,..., N }.

TL;DR: In this article, a more sophisticated algorithm is presented which preserves exactly the large waveform structures that are not removed by the hysteresis cursor while removing smaller fluctuations in the same way as the standard algorithm.

TL;DR: Efficient data structures for picture processing are developed on the basis of graph-theoretic concepts by a directed split-and-merge algorithm and subsequent analysis is performed by examining either the region adjacency graph (RAG) or the vertex adjacencies graph (VAG).

TL;DR: The Tiffs ratio as discussed by the authors is a natural measure of noncompactness for digital pictures, provided that P and A are properly defined and can be computed based on classical results regarding evaluation of the area and perimeter of a polygon whose vertices are lattice points.