Showing papers on "Pyramid (image processing) published in 1981"
1 Jan 1981
TL;DR: Pixel to pixel correlations are first removed by subtracting a low-pass filtered copy of the image from the image itself, and a net data compression is achieved since the difference, or error, image has low variance, and the low- pass filtered image may be represented at reduced sample density.
Abstract: Pixel to pixel correlations are first removed by subtracting a low-pass filtered copy of the image from the image itself. The result is a net data compression since the difference, or error, image has low variance, and the low-pass filtered image may be represented at reduced sample density. Further data compression is achieved by quantizing the difference image and repeating the encoding process for the low-pass filtered image.
52 citations
TL;DR: Two related methods for the hierarchical representation of curve information are presented and an edge quadtree representation is presented, which is a variable-resolution representation of the linear information in the image.
51 citations
1 Apr 1981
TL;DR: A capsular introduction to the theoretical framework and experimental applications of the Polar Exponential Grid (PEG) transformation, in the context of image analysis, and presents the PEG transform as a motif for a class of problems in stochastic estimation of object boundaries.
Abstract: This paper provides a capsular introduction to the theoretical framework and experimental applications of the Polar Exponential Grid (PEG) transformation, in the context of image analysis. The PEG transformation is an isomorphic (1) representation of the image intensity array that simplifies, and potentially offers new insights about, a variety of tasks in computational vision. We describe the PEG transform representation; we briefly survey its functional precursors in optical computing and image processing. We then give an example of PEG-based image analysis for rotation-and-scale variant template matching and, present the PEG transform as a motif for a class of problems in stochastic estimation of object boundaries.
11 citations
1 Sep 1981
TL;DR: A comparative study of FLIR segmentation algorithms has been conducted in cooperation with Westinghouse Defense Systems Division, and the best technique, superspike, extracted regions corresponding to over 88% of the targets, and had a false alarm rate of 1.6 false regions per true target.
Abstract: : A comparative study of FLIR segmentation algorithms has been conducted in cooperation with Westinghouse Defense Systems Division In the Maryland portion of the study, four techniques (two and three-class relaxation, pyramid linking, and superspike) were tested on a Westinghouse-supplied database of 51 images obtained from NVL and other sources (Two other techniques, superslice and pyramid sport detection, were rejected after preliminary studies ) The best technique, superspike, extracted regions corresponding to over 88% of the targets, and had a false alarm rate of 16 false regions per true target
3 citations
12 Nov 1981
TL;DR: Two related methods for hierarchical representation of curve information are presented and edge pyramids are defined and discussed.
Abstract: Two related methods for hierarchical representation of curve information are presented First, edge pyramids are defined and discussed An edge pyramid is a sequence of successively lower resolution images, each image containing a summary of the edge or curve information in iLs predecessor This summary includes the average magnitude and direction in a neighborhood of the preceding image, as well as an intercept in that neighborhood and a measure of the error in the direction estimate An edge quadtree is a variable-resolution representation of the linear information in the image It is constructed by recursively splitting the image into quadrants based on magnitude, direction and intercept information Advantages of the edge quadtree representation are its ability to represent several linear features in a single tree, its registration with the original image, and its ability to perform many common operations efficiently
1 citations
1 Mar 1981
TL;DR: The method of image segmentation based on creating links between pixels in successive layers of a pyramid of reduced resolution versions of the image is extended to links based on multiple features, such as color components or neighborhood properties.
Abstract: : A method of image segmentation has been developed based on creating links between pixels in successive layers of a pyramid of reduced resolution versions of the image. In the original implementation of this method, the links were based on comparing the values of a single feature, (average) gray level, for each pixel. In this note, the method is extended to links based on multiple features, such as color components or neighborhood properties.
TL;DR: A novel scheme for simplifying pyramidal representations and procedure for rapid access to and selective use of particular areas and local control of detailed fineness are discussed in conjunction with the architectural considerations for implementing the system.
Abstract: This paper concerns a pyramidal representation of images. The objective of this study is to represent an image with as small a number of data words as possible in a memory without distorting the feature extraction facility inherent in pyramidal representations. First, a novel scheme for simplifying pyramidal representations is presented. Simplification is essentially based on the reduction of the number of informative elements observed in a window space during the hierarchical process of image representation. Following a brief explanation of the window pattern simplification process is a description of an overall procedure for simplifying complex binary images. Finally, for images which are not necessarily binary, procedure for rapid access to and selective use of particular areas and local control of detailed fineness are discussed in conjunction with the architectural considerations for implementing the system.