How to Separate out the disconnected regions of a raster into independent rasters?

[ShaunakVairagare]

Please refer to the attached image. The overlay on the map shows a raster file with disconnected circles. I want to split each of those circles into independent rasters in one shot. Is that even possible? If yes how? If not whats the fastest way to do it (avoiding as much donkey work as possible)?

[PrasantaBhattarai]

If in ArcGIS 10, you can use the Iterators in model builder to clip out the raster with each region. If you already have a polygon feature for these regions, you can use it. If not, Reclassify your raster to a single value and convert it to polygons using Raster to Polygon. You can then use model builder and insert > iterators > Iterate feature selection. Add Clip raster tool into model and use iterated feature as output extent. For clip tool, check the option to �??use input feature for clipping geometry�?�

[ShaunakVairagare]

Thanks vattarai, that is a good idea. I have one problem though. I do have those features, thats how i clipped the circles in the first place. But again, i have those features in one layer. How do I saperate them now? 😛 I have these circular features in one layer. Each Circle has a unique ID. Can i Split and save these features into separate layers automatically and use them in the model you described earlier?

[PrasantaBhattarai]

How do I saperate them now? 😛 I have these circular features in one layer. Each Circle has a unique ID. Can i Split and save these features into separate layers automatically and use them in the model you described earlier?

You do not need to seperate the features into multiple feature layers. When you are using iterate feature selection in model builder, each polygon feature will be selected and used as clipping extent. The clip tool will run in multiple iteration each time selecting a different polygon feature from your layer. See more examples of using iterators in ModelBuilder on our web-help.

[ShaunakVairagare]

Yup I just noticed that! Thanks again for guiding me through! I am fairly new to using ArcGIS. 🙂

[ShaunakVairagare]

Hi  Prasanta,

Thanks! the model works perfect!

I have some question here:

1. I have say 20 circles. Some of them fall completely out of the lidar area. In this case the clipping returns complete raster layer, instead of no raster layer.  How can I invert this?

2.  Can i save these value variables coming out in a text file?


Thanks!
Shaunak