Thinning algorithms for gray-scale pictures
Abstract
Elongated black objects in black-and-white pictures can be 'thinned' to arcs and curves, without changing their connectedness, by repeatedly deleting black border points in their neighborhoods. In order to prevent thin arcs from shrinking at their ends or isolated points from vanishing, black points that have fewer than two black neighbors should not be deleted. A number of such thinning algorithms have been described in literature. A generalization of the notion of connectedness to gray-scale pictures was proposed by Rosenfeld (1977). In this 'fuzzy' definition of connectedness, two points are called 'connected' if there is a path joining them that contains no point lighter than both of them. Using this definition, it is possible to formulate a gray-scale thinning algorithm in which a point is set equal to the lightest of its neighbors if doing so does not disconnect any pair of its neighbors.
- Publication:
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IEEE Transactions on Pattern Analysis and Machine Intelligence
- Pub Date:
- January 1979
- Bibcode:
- 1979ITPAM...1...88D
- Keywords:
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- Algorithms;
- Black And White Photography;
- Gray Scale;
- Image Processing;
- Satellite-Borne Photography;
- Video Data;
- Computer Techniques;
- Digital Systems;
- Iterative Solution;
- Landsat Satellites;
- Pattern Recognition;
- Photointerpretation;
- Instrumentation and Photography