image curve recognition 1

[wayeb]

I have an elevation map in a BMP format and i would like to draw the geometry with autocad. Is it possible to detect the curves automatically on the bitmap image?

 

[Rich2001]

Try RasterVect software

http://www.rastervect.com

Or import and trace.

 

[countgallo]

The simple answer is no it's not possible for AutoCAD to automatically detect any curves. The reason is that a raster(bitmap) is a series of pixels (dots) and as such a curve will also be a series of dots and not a true curve.

There is some software that attempts to convert these dots to vectors but this really is hit and miss since there will always be discrepencies in the raster to vector converter software as to which dot to follow next. For example, when does a line change course, is it this dot or that one?

However, some converters can and do save a lot of time and effort but you'll probably spend a lot of time editing and cross-referencing the original drawing/map to see if the conversion has made the right decision and followed the correct path. This can lead to serious errors of misjudgement on behalf of the CAD operator.

Best bet is to import the scan, choose a scale, then trace around the image.


HTH

 

[Bayou]

Autodesk has CadOverlay (for 2000i or older) or Raster Design (for 2002), that has the ability to vectorize raster images. The process can be easy or very difficult, depending on the image.
As far as the following of the dots with Raster Design, the user tends to lead it through. The more clutter in the image, the more tedious it becomes. USGS maps are impossible because they have so many other things on them besides topo lines.
Even with Raster Design, I tend to just redraw the lines. The user is able to set the Snaps to image pixels.
Or with just Acad, insert the image and just trace over the lines with plines. Then you can some out the curves by splining the plines. It will take less time then you think.