create area features

energyenergy Global Mapper UserPosts: 384Trusted User
edited April 2013 in Technical Support
Hi
I need to digitize a complex topographic map, I am thinking "create area features from the equal values in selected layer" options is useful, but area features dont help me, but creating line featues instead of area features is more helpful, because the created lines are contours at the same time , editinng line are easier.it cant be difficult for only one color, it possible to add a options?

Comments

  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited April 2013
    The equal value areas could really only be for areas since an image is really a series of tiny rectangles (pixels) that you can then combine when the colors match. The same wouldn't directly apply for lines since an image isn't made up of lines.

    Now you might end up with areas that were created from drawn lines on the raster, so they are long thin areas. You could select those with the Digitizer tool and choose the advanced feature creation submenu option to create area skeletons to create lines from the center of the areas. This would only work for a very small set of areas though.

    More advanced raster-to-vector techniques would allow creating lines directly from a raster, but that would be a much more advanced option.

    Thanks,

    Mike
    Global Mapper Guru
    gmsupport@bluemarblegeo.com
    http://www.bluemarblegeo.com/
  • energyenergy Global Mapper User Posts: 384Trusted User
    edited April 2013
    I am sorry I dont understand second paragraph excatly, please can you explain clearly what I can do?
  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited April 2013
    If you have Global Mapper v14.1 (or later) you can select area features, then right-click and select the Advanced Feature Creation submenu to 'Create Area Skeletons/Center Lines'. This will create lines forming a skeleton of the areas, which for a long thin area that was vectorized from a line in the raster it might be very close to the line that you want.

    Thanks,

    Mike
    Global Mapper Guru
    gmsupport@bluemarblegeo.com
    http://www.bluemarblegeo.com/
  • energyenergy Global Mapper User Posts: 384Trusted User
    edited April 2013
    yes I tried trial 14 but I think this is not useful, thanks...
  • tjhbtjhb Global Mapper User Posts: 454Trusted User
    edited April 2013
    In case you are interested in investing money in a specific tool for this, I recommend Vextractor (www.vectrasoft.com). I don't know of anything better for tracing vector imagery into lines. It has output to shapefile and mif, among other formats. There is a free trial.
  • GeoGeo Global Mapper User Posts: 92Trusted User
    edited April 2013
    tjhb wrote: »
    In case you are interested in investing money in a specific tool for this, I recommend Vextractor (www.vectrasoft.com).
    Vextractor url is http://www.vextrasoft.com/
    tjhb wrote: »
    I don't know of anything better for tracing vector imagery into lines. It has output to shapefile and mif, among other formats. There is a free trial.
    Did you try Easy Trace ? http://www.easytrace.com/
    a free version is available at http://www.easytrace.com/program/et799_en/
  • tjhbtjhb Global Mapper User Posts: 454Trusted User
    edited April 2013
    Thanks Geo for correcting my error.

    And even more thanks, for pointing to EasyTrace. With CUDA too--though only in beta for now I think? (I can only read a little bit of Russian.) This looks very good.
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