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Contour line - Wikipedia
A contour line (also isoline, isopleth, or isarithm) of a function of two variables is a curve along which the function has a constant value, so that the curve joins points of equal value. It is a plane section of the three-dimensional graph of the function f(x, y) parallel to the (x, y)-plane.In cartography, a contour line (often just called a "contour") joins points of equal elevation ......
 Contour Extraction and Visulization from Topographic Maps
Contour Extraction and Visulization from Topographic Maps ... elevation data can be extracted and utilized by recognizing contour lines in maps. In this project, the viability of contour extraction using image segmentation and Delaunay triangulation for line reconstruction ... simple as using the Moore contour tracing algorithm, as is suggested ......
CONTOUR LINES EXTRACTION AND RECONSTRUCTION FROM ...
maps are the contour lines (isolines), which are imaginary lines that join different points located at the same elevation. The isolines result from intersecting the ground surface with horizontal, parallel and equidistant planes. Topographic maps usually show not only the contours but also other thematical layers which overlap: streams and other...
Contour line - definition of contour line by The Free ...
Define contour line. contour line synonyms, contour line pronunciation, contour line translation, English dictionary definition of contour line. n. A line on a map that joins points of equal elevation. n a line on a map or chart joining points of equal height or depth....
Lab 1: An Introduction to Topographic Maps
Elevation and Contour Lines: Elevation, typically measured relative to sea level whose elevation is arbitrarily said to be zero, is represented by contour lines on topographic maps. A contour line is a line of equal elevation. Contour lines are vertically spaced using contour intervals. For instance, USGS topographic maps commonly space contour ......
image - Topographic map Contour lines extraction - Stack ...
Thanks again Boo. I have checked with Photoshop the proposed algorithm you described (on an image from Wiki). It does help masking the contour lines from the background. I believe that with the combination of some other filters and some algorithms which I have seen described in some documents - I can get a good result. – Nati Cohen Oct 26 '11 ...
algorithm - Drawing a Topographical Map - Stack Overflow
The trick I used to anti-alias the contour line is to mix the contour line color into both pixels, proportional to their closeness to the idealized contour line. Maybe some examples will help. Suppose that the current pixel is at an "elevation" of 12 ft, a neighbor is at an elevation of 8 ft, and contour lines are every 10 ft....
A new approach to the reconstruction of contour lines ...
Thanks to the specific color of contour lines, their extraction from topographic maps can be done without more effort. After extracting the contour lines, gaps may occur because other features in topographic maps can overlay and cross the contour lines. Gaps cause problems for generation of DEM and construction of 3D simulation....
Contours - USF
Open contours also occur when line fragments are linked together-for example, when line fragments are linked along a stroke in a drawing or sample of handwriting. A contour may be represented as an ordered list of edges or by a curve. A curve is a mathematical model for a contour. Examples of curves include line segments and cubic splines....
I/O-Efficient Algorithms for Computing Contours on a Terrain
called contour tree [9] encodes a \seed" for each contour of K. Many e cient internal-memory algorithms are known for computing a contour tree; see e.g. [9]. Hence, one can e ciently construct a contour map of K. This approach of tracing a contour has been extended to higher dimensions as well, e.g., the well-known marching-cube algorithm for...
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