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raster to vector conversion

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#16
ELeFevre

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I've found that the live-trace is invaluable when you need to instantly recreate a simple object like a logo. It's also great for a taking an element of photo and turning that object into a vector symbol. Vectorizing an image into a map is a completely different ball-game. If you have access to a program like Erdas Imagine, you can create an accurate vector map from an image using either the Unsupervised or Supervised classification tools.

I agree with Frax that the bezier tool in Illy will give you the best results and will require the least number of points and paths. Live Trace will do the same thing, but with more of everything, and the results are more difficult to work with. Learning all of the in's and out's of the bezier tool is the way to go. Plus, once you get it down, re-creating an object is really fast.



#17
frax

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I think live trace is quite ok (actually it is a technological marvel, but anyways) but the big problem is that it doesn't know anything about topology. So it is ok for stray polys, or linear objects, but if need to work with adjoining polygons (like continous classified data) you might get problems with polygons not lining up perfectly.
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#18
tom harrison

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I'm very much old school because I still use Freehand 9 - because the RIP for my old workhorse HP plotter can't be upgraded to OS X. When I used to manually convert images, I opened a 4-bit scan of a topo quad in a simple program called ColorIt, selected only the color I wanted, one layer at a time, cleaned up the scraggly bits with the pencil and eraser tools, imported the black and white image to Freehand and used the Trace tool. Still had to do some joining and cleanup, but it fit the quad image perfectly.
However, I recently found someone who can give me an R12 AutoCad vector image that is right on the money, for very little money. Check with the local drafting supply house - they probably know someone who does that kind of raster to vector conversion for architects.

#19
R. Smith

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It all depends on the scope of the work you need to migrate. This is my experience.

Several years ago the BC Provincial Government went to RFP to have a few traditionally produced topographic maps converted to fully digitally produced products. They wanted the new digitally produced map to be an exact replica of the previous edition. I tried digitizing portions of the map, but I found it impossible to replicate the linework 100%. Eventually I gave up and found a local third party who had developed an automatic raster to vector program and they were able to tighten things up enough to replicate the linework for me. They also did a great job of converting the type as well. The raw product was a little rough but all it really needed was proper layering, manipulation to meet the graphic specifications and a bit of tweeking to the type. Output was simple enough. Printing was flawless. The cost to update the topo sheet and to migrate it came out to be significantly less then the government had been paying for traditional updates. All done on a Mac in Illustrator in my basement.

Unfortunately the government has since axed it's hardcopy topo program and with it went the contracting work for updating and migration. But it was fun while it lasted.

There's an old image of the Bowron Lakes Park Map that I also used this technique on on my website at:

http://www.mapsunlim...le/Bowron1.html


Rod




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