topic Display of two overalapping mosaics in Data Management Questions

Display of two overalapping mosaics

Anonymous User — Tue, 15 May 2012 12:38:40 GMT

Original User: KevinCRDA

Hello,
I have two mosaics that I'm working with. I want to put these two mosaics together in a ArcMap document. The mosaics reprensents an urban area of my region and the other is the rural areas.
The first mosaic have a white background (generated with DVP), and the second have a black background (generated with Summit Evolution). I would like to put the first one over the second one, but the white background makes it very ugly because it overlaps the other mosaic.

Is there a way to change the white background into "transparency" in ArcMap so that my two mosaic would overlapp better ? I can't regenerate the first mosaic, so I can't change the background...

thanks

Re: Display of two overalapping mosaics

Anonymous User — Tue, 15 May 2012 21:18:25 GMT

Original User: mharlow

There are a few ways to remove either the black or white backgrounds when displaying either image.
I recommend right-click the layer, click the Symbology tab, and check the options for the background. (described here)

If you need something where the background doesn't also remove any white or black pixels within the image, you could create a mask.

Then you can mosaic using an option like the Mosaic button on the Image Analysis window.

Re: Display of two overalapping mosaics

Anonymous User — Wed, 16 May 2012 14:14:24 GMT

Original User: KevinCRDA

Thank you.

Finally, I used the Raster clip tool with a polygon I created. It worked well but it has changed the brightness of the image.

I would like to equalize with an "histogram match" to get the two image in the same light, but I didn't find a tools which does that. Do you know if it is possible and how I could do this with ArcMap ?

Thanks again

Re: Display of two overalapping mosaics

MelanieHarlow — Wed, 16 May 2012 14:29:24 GMT

The image may appear different or brighter because statistics were generated for the newly created raster generated from the tool you used. By default the image is stretched according to the statistics. One way to turn off the stretch is to click Windows > Image Analysis to open the Image Analysis window. Select the raster layer in the top of the window and change the Stretch drop-down to NONE.
Learn about the display settings on the Image Analysis window

Color correction between two or more images can only be accomplished using a raster catalog or mosaic dataset.
For an overview on color correction in ArcMap, see Color correcting raster data
To use a raster catalog, see Color balancing a raster catalog. There is also a tutorial.
To use a mosaic dataset, see Color correcting a mosaic dataset. There is also a tutorial.