Extract by mask: it is choosing the area outside of the polygon instead of inside

[Anonymous User]

Original User: turtlegirl33

Hello, I've been looking through the forum and can't seem to find the answer to my issue, excuse me if I am being redundant 🙂

I have a DEM files that i mosaic ed together to form one big file. From this I am trying to extract a certain area that is one shapefile that has 52 polygons.
Now i don't know if its something in the way that these polygons do not touch (originally the polygons were made in googleearth then the KML was transferred over) and that is the issue or if it's something else.
Any input would be great as I am thoroughly stumped and frustrated with this problem!

This image shows the mosaic before i try to extract it by the polygon shown in the brown-orange color.
[ATTACH=CONFIG]15369[/ATTACH]


This is what happens afterwards:
i hollowed the polygon so you can see the weird triangles that appear
[ATTACH=CONFIG]15370[/ATTACH]


Thank you all for your help!!!

[EricRice]

You could just try running the clip tool under Data Management Tools > Raster > Raster Processing,  or if you wish to use Extract by Mask, you could try to convert the polygons to raster and use the resulting raster as the mask input.  I've never seen Extract by Mask do that before....Weird.  Hopefully one of the other options will get you going.

Best,
Eric

[Anonymous User]

Original User: jvizy

I recently experienced the same issue and found the problem is cause by a geometry problem with the clipping polygon. The geometry of the polygon was incorrect even though it looked ok. The fix was to run the geoprocessing tool Repair Geometry under Data Management Tools > Features on the polygon feature class.

Hope this helps

John