Hi,
I have imported several arcGIS shapefiles into Idrisi, and need to perform a supervised classification on a landsat image. I want to use these polygons as my training sites. How can I assign these polygons into different classes and create training sites? The only other way I have created training sites is to digitize them but in this case I have already imported the polygons I want to use.
Thanks
Stephanie,
You will want to rasterize the polygon vector file. That should become your training site file you can use for Makesig. Use the module RASTERVECTOR.
James
Hi James,
Will I have to rasterize all of my polygon vector files? There are over 30 of them, and each represent a different class. How can I make sure that MAKESIG knows which belong to each class?
You can rasterize them all into one raster file. Or, since you created them in Arc, combine them in Arc into one Shape the import that file. Then you would have a single file.
James
Hi James,
Great, thanks! One last question, after I combine them into one raster file, how can I then assign different IDs for the shapes? For example, 3 shapes may be classified as "trees" whereas another 3 may be "water". I know MAKESIG needs the IDs/classes for the shapes.
Before you combine them, give them the IDs values you want, then combine.This would be the easiest way. Makesig will ask you to give legends to all the IDs found in the training site file.
James
Great, that makes sense. Do you know how I can access the ID values? The metadata panel for each shape only states the ID type.
I think I may have found it. I changed the categories row for every shape to their respective class.