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PostPosted: Tue Dec 09, 2008 2:14 am 
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Hi,

I work a lot with raster maps as a background. They are topographic maps without hillshade, come as 1-band rasters (geotiff) and usually have 8, 10 or 12 colors defined in a colormap. Unfortunately some of those colors in the colormaps are absolutely awful, so I'm looking for a way to change the colormap.

I can change the colors each time I load the data into ArcMap and I suppose i could then create a .lyr-file and continue using this, but I'd like to "fix" the problem at its root so I won't have to do this step over and over again.

Does anyone know how to access the colormap and how to change those settings? When I use software like Photoshop, will I loose the georeferencing?

Thanks,
Kathi

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PostPosted: Tue Dec 09, 2008 6:44 pm 
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Kathi,
Below I have provided some links that may help you out. The issue I had with my aerials was that the color options (under properties of the image) kept changing to ‘Standard deviation’ which would brighten up the image and make it very grainy. Once I changed it to ‘None’ it was fine. If the aerials are already incorrect before bringing into ArcMap, but you correct it (with ArcMap) and like your settings you could try do the following before or after depending on the changes.

1.)As you mentioned save a layer file.

2.)Create a raster catalog (I use this), but it requires a lot more space depending on the aerials size. When managing the catalog I believe the settings will stay the saved if modified within ArcCatalog (I would need to verify that though). I have not adjusted mine since creating the catalog. Also depending on the amount of aerials you need the load it might be a lengthy process.

3.)Try to Create a raster dataset and view the link below for color correcting and see if that might help. I have not done this yet, so I’m not sure if that would help (it appears to create just one overall map).

4.)Purchase ArcGIS Image Server :ugeek: , I believe that extension allows for multiple color adjustment settings not offered in ArcGIS ArcMap. It’s for the hardcore image people who do a lot of image analysis.

If you modified the images in Photoshop or another program keep the name and location the same to retain the geo-reference). Just make sure you do not move the files that come along with the tif. The spatial reference is not store in the image itself, but in the files that are in the same folder, same name but different extension. If I can recall it will be 2 or 3 files tied to that aerial (tif). Make sure you test this out on a copy before hand and not the original.
Also check the default options link below, if that doesn’t work look around in the ArcToolbox and see if you can use any of those tools to adjust colors, etc.
I hope this helps, I will do some further testing to see if I can get settings to stay changed if none of these suggestions work for you..
Since I’m typing from memory I may have missed something :lol:
Have a good day/night and good luck,
Daniel

Create Raster Catalog
http://webhelp.esri.com/arcgisdesktop/9 ... Management)

About setting default raster display options
http://webhelp.esri.com/arcgisdesktop/9 ... ay_options

Color correcting using raster data
http://webhelp.esri.com/arcgisdesktop/9 ... aster_data

Create a raster dataset
http://webhelp.esri.com/arcgisdesktop/9 ... Management)

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PostPosted: Thu Dec 11, 2008 9:25 am 
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Squire

Joined: Tue Dec 02, 2008 5:04 am
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Cool, thanks for the links!

For work in ArcMap I have created raster catalogs and in fact layer files pointing to the raster catalog, one with the colors I like and one for those cases where I need my background in grayscale. They work fine, and I'll probably stick to those in the future.

However, I just learned that MapInfo doesn't allow for changes of individual colors of rasters. So in order to make my maps look nice in MapInfo as well, I'll probably change some of the colors using Photoshop. As you pointed out correctly the georeferencing info is in the .tfw-file and won't be touched by the color shift. ;)

(You may ask yourself, why someone living in the world of ERSI would all of a sudden aquire MapInfo as well. The reason is that we need full 3D capabilities for a project, and I found a software package from Encom that provides this capability, but it only runs as an add-on of MapInfo - by the way at a fraction of the cost ESRI charges for their more limited 3D components...)

Cheers,
Kathi

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PostPosted: Wed Mar 11, 2009 6:34 am 
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Joined: Sun Mar 01, 2009 10:24 am
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mapinfo can change it. use Mapimagery. but for the licensed version only.


"Does anyone know how to access the colormap and how to change those settings? When I use software like Photoshop, will I loose the georeferencing?"

mapimagery wont touch your georeferencing. its still the same as it was before you change it. For Discover try the Image module instead.

Cheers,
urien


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PostPosted: Wed Mar 11, 2009 7:18 am 
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Joined: Tue Dec 02, 2008 5:04 am
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Discover's Image module can change colormaps?! Great!! Ican see there is still a lot I need to learn about this whole software package...

Thanks for your help!
Kathi

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