This paper proposes a method of implementation of automatic contour line extraction from scanned digital topographic maps. First, color image segmentation is executed to recognize the features on digital topographic maps, second, morphological and filtering operations are presented to eliminate all unwanted information from digital topographic map except from contour lines. Then, resolving the ...

Contours maps (such as topographic maps) compress the information of a function over a two-dimensional area into a discrete set of closed lines that connect points of equal value (isolines), striking a fine balance between expressiveness and cognitive simplicity. They allow humans to perform many common sense reasoning tasks about the underlying function (e.g. elevation). This paper analyses an...

Recognition of features in topographic maps is useful for GIS applications. In particular, 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 was investigated. Results suggest that, while the method has a high success rate for well beha...

Terrains are an essential part of outdoor environments. Terrain models are important for computer games and applications in architecture, urban design and archaeology. A popular and intuitive way to represent terrains is by contour maps. In order to render such representations in 3D the contours must be labelled with height values and converted to Digital Elevation Maps (DEM), which are regular...

Contour maps provide a general method for recognizing twodimensional shapes. All but blank images give rise to such maps, and people are good at recognizing objects and shapes from them. The maps are encoded easily in long feature vectors that are suitable for recognition by an associative memory. These properties of contour maps suggest a role for them in early visual perception. The prevalenc...

Shadowed contour lines vary line width. Illuminated contour lines additionally vary color based on an angle of illumination. Illuminated and shadowed contour lines date back to the midnineteenth century, but their effectiveness compared to conventional contour lines has not been fully examined. Currently, illuminated and shadowed contour lines are not widely used in computer-based cartography b...

It is extremely difficult to locate the contour of the prostate in B-scan ultrasound images automatically by computer because of low resolution and high noise levels. In this paper we present a semi-automatic prostate contour extration scheme, which is based on the wavelet transform and active contour models, or snakes. The ultrasound image is first decomposed into edge maps at different resolu...

Single neurons in primate V2 and cat A18 exhibit identical orientation tuning for sinewave grating and illusory contour stimuli. This cue invariance is also manifested in similar orientation maps to these stimuli, but in V1/A17 the illusory contour maps appear reversed. We hypothesized that this map reversal depends upon the spatial frequencies of the inducers in the illusory contours, relative...