Time to get blogging again - I posted a new Maplet

Time goes by, and I periodically remind myself that I need to get back to my blogging. Well, no time like now. I'm starting with the announcement of a new Maplet - one of my GIS tips. This one is for ArcGIS 10 (specifically 10.2.2 but should work in all the 10s). I've had a few clients ask about this technique, so I thought I'd post it online as a reference.

The technique is for clipping imagery to a boundary. Specifically this is an issue where you may have a large photomosaic set in an ECW or similar file format that requires a rectangular dataset, but your imagery is made up of a non-rectangular tiles combined. The area not covered by images becomes a blank white area. That doesn't work too well when you're overlaying different datasets, particularly if you are overlaying different imagery sets at different scales.

Most of the time, this white border, or collar as it is sometimes called, can be removed by assigning the color value of the collar as a background color and set to not display, but in this case, the border is a range of color values. In this case, the trick is to have a boundary around the actual image area and use that boundary as a clipping edge.

The tricky part is finding where to do this. It is found in the Image Analysis from the Windows pull-down.

  Check out the video for details: