Journal•ISSN: 0146-664X

# Computer Graphics and Image Processing

About: Computer Graphics and Image Processing is an academic journal. The journal publishes majorly in the area(s): Image processing & Edge detection. It has an ISSN identifier of 0146-664X. Over the lifetime, 565 publication(s) have been published receiving 46551 citation(s).

Topics: Image processing, Edge detection, Digital image processing, Tree (data structure), Image segmentation

##### Papers

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Abstract: A set of texture features based on gray level run lengths is described. Good classification results are obtained with these features on a set of samples representing nine terrain types.

1,677 citations

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TL;DR: It is shown that skeletons can be produced by simple procedures and since these are based on Euclidean distances it is assumed that they are superior to skeletons based on d4−, d8−, and even octagonal metrics.

Abstract: Based on a two-component descriptor, a distance label for each point, it is shown that Euclidean distance maps can be generated by effective sequential algorithms. The map indicates, for each pixel in the objects (or the background) of the originally binary picture, the shortest distance to the nearest pixel in the background (or the objects). A map with negligible errors can be produced in two picture scans which has to include forward and backward movement for each line. Thus, for expanding/shrinking purposes it may compete very successfully with iterative parallel propagation in the binary picture itself. It is shown that skeletons can be produced by simple procedures and since these are based on Euclidean distances it is assumed that they are superior to skeletons based on d4−, d8−, and even octagonal metrics.

1,604 citations

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TL;DR: Elliptic properties of the Fourier coefficients are shown and used for a convenient and intuitively pleasing procedure of normalizing a Fourier contour representation.

Abstract: A direct procedure for obtaining the Fourier coefficients of a chain-encoded contour is presented. Advantages of the procedure are that it does not require integration or the use of fast Fourier transform techniques, and that bounds on the accuracy of the image contour reconstruction are easy to specify. Elliptic properties of the Fourier coefficients are shown and used for a convenient and intuitively pleasing procedure of normalizing a Fourier contour representation. Extension of the contour representation to arbitrary objects at arbitrary aspect angle is discussed. The procedures have direct application to a variety of pattern recognition problems that involve analysis of well-defined image contours.

1,578 citations

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TL;DR: An approximation algorithm is presented which uses an iterative method to produce polygons with a small—but not minimum—number of vertices that lie on the given curve that justifies the abandonment of the minimum-vertices criterion.

Abstract: The approximation of arbitrary two-dimensional curves by polygons is an importanttechnique in image processing. For many applications, the apparent ideal procedure is to represent lines and boundaries by means of polygons with minimum number of vertices and satisfying a given fit criterion. In this paper, an approximation algorithm is presented which uses an iterative method to produce polygons with a small—but not minimum—number of vertices that lie on the given curve. The maximum distance of the curve from the approximating polygon is chosen as the fit criterion. The results obtained justify the abandonment of the minimum-vertices criterion which is computationally much more expensive.

1,201 citations

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TL;DR: Efficient (linear time) algorithms have been developed for the Boolean operations, geometric operations,translation, scaling and rotation, N-dimensional interference detection, and display from any point in space with hidden surfaces removed.

Abstract: A geometric modeling technique called Octree Encoding is presented. Arbitrary 3-D objects can be represented to any specified resolution in a hierarchical 8-ary tree structure or “octree” Objects may be concave or convex, have holes (including interior holes), consist of disjoint parts, and possess sculptured (i.e., “free-form”) surfaces. The memory required for representation and manipulation is on the order of the surface area of the object. A complexity metric is proposed based on the number of nodes in an object's tree representation. Efficient (linear time) algorithms have been developed for the Boolean operations (union, intersection and difference), geometric operations (translation, scaling and rotation), N-dimensional interference detection, and display from any point in space with hidden surfaces removed. The algorithms require neither floating-point operations, integer multiplications, nor integer divisions. In addition, many independent sets of very simple calculations are typically generated, allowing implementation over many inexpensive high-bandwidth processors operating in parallel. Real time analysis and manipulation of highly complex situations thus becomes possible.

1,052 citations