Raster to Vector Conversion: Solid areas to Polylines

Raster to Vector conversion can be achieved in many ways. WiseImage software provides a method that can allows a conversion that is usually much quicker than other digitization methods. The following illustrates how park areas from a 1936 New Haven paper map can be extracted as a vector file.
After scanning the historic New Haven paper map, it can be brought into WiseImage as a raster -in this case as a .tif file. The park areas (the green areas on the map) can be selected by using the color picker to select the pixels that fall within a range of green color.
The pixels within the range of green that represents New Haven parks can be picked specifically from the raster by zooming in to different portions of it.
A final raster is extracted based on the selection of pixels as a separate layer. This contains the raster pixels that represent the New Haven parks, leaving out the rest of the features on the map.
Additional tools in WiseImage allow the user to extract a more accurate raster that represents the parks. These tools include, blur, unsharp mask, median, speckle remover, hole remover, inversion, thinning, and thickening.
Using countour coupling, outlines can be extracted from the the solid raster areas representing the parks. This final raster layer can then be converted to a vector with the click of a button. WiseImage exports in a CAD vector format (.dxf) which can be read by ArcView or converted to a shapefile.




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Last update: January 13, 2003 19:18
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