I am trying to do the steps below (using Editor and ArcScan...w/ArcInfo 10 license). I am stuck on Step #2. I can't seem to find a way to get the ArcScan toolbar to recognize the Raster layer (which is in the same fgdb as the empty line feature which I created).
The ArcScan toolbar just remains grayed out...I don't know what I'm missing...
Any idea what might be up??
Here are the steps I've followed (from here: forums.arcgis.com/threads/11744-Polygon-to-centerline)
Using ArcScan to create centerlines from polygons (roads, paths, water bodies):
Step 1: Create a raster from your polygons. - Use �??features to raster�?� or �??polygon to raster�?� tool. Make sure that cell size for new raster is small enough that even narrowest sections of a polygon get represented. For sidewalks, cell size of 3ft worked, default cell size of ~10ft did not (missing parts of path, disconnected) - Imperative to Reclassify resulting raster into a �??bi-level image�?�, with all useful pixels (the ones you wish to convert to lines, typically non-0 values in your raster) reclassified as 1, and NoData reclassified as 0. After that, �??You can use either the ArcMap Unique Values or Classified rendering options to separate the raster into two colors�?�; raster must be symbolized in two unique colors.
Step 2: Set up editing environment (ArcScan works inside Editing environment only) - Create a new empty line file in which newly created centerlines will be saved - Enable ArcScan extension under Customize-Extensions pulldown menu, if you haven�??t yet. - Start an Edit Session, designating the new empty line file/gdb as target; remember to create a feature template for new empty line fine - Add ArcScan toolbar (Customize �?? Toolbars)
Step 3: Use ArcScan to create lines. - If everything is set up correctly, the rasterized polygons will show up as an option in ArcScan�??s pulldown menu for �??Raster:�?� target. - Click Vectorization pulldown menu, chose �??Generate Features�?� - Check to see that all of your original polygons generated a center line. Some of my shortest paths do not generate a centerline; turning Noise Level to 0 in Vectorization pulldown-Vectorization Settings helps some of these centerlines to come through; using �??Show Preview�?� in Vectorization pulldown helps you see whether changes you�??ve made to settings and options are having an affect (hit Apply for every change to show in preview) - For ESRI Help on ArcScan: http://help.arcgis.com/en/arcgisdesk...0001000000.htm
