The Problem:
Adjacent rasters of continuous data that do not contain the
same maximum and minimum cell values and/or the same range of cell values can
not be symbolized with exactly the same color ramps. A typical
example might be two or more adjacent DEMs that have been
classified manually to show elevations in equal intervals of, say,
20 meters. A color ramp applied to one results in a shade
of green for elevations of, say, between 320 and 340 meters, while
the same color ramp applied to the other gives a slightly
different shade of green for the same elevation interval. This
will always be the case if the two raster have different
numbers of intervals, and/or if the maximum and minimum cell
values are not identical. Short of manually setting every color in
the second raster to match that of the first, how can this problem
be eliminated?
An obvious solution would be to merge ("mosaic") the rasters,
so a single color ramp could be used (directions for doing so are
given in another tip). For very large rasters this
is not feasible, and in other situations it may not be desirable.
The Solution:
Tools that copy and paste raster symbology from one raster
layer to another!
Such tools are available as "Samples" in the ArcObjects
Developers Toolkit that comes with ArcGIS. During a typical
installation they are stored at C:\arcgis\arcexe82\ArcObjects
Developer Kit\Samples\Raster\CopyRasterSymbologyBetweenLayers.
Directions for installing and using these and other ArcObjects
tools can be found online at
http://arconline.esri.com/arcobjectsonline/.
But...YOU CAN NOT INSTALL ARC OBJECTS TOOLS ON THE COMPUTERS IN THE
GEOLOGY BLDG. - TO DO SO REQUIRES ADMINISTRATOR PRIVLEDGES.
Happily, these particular tools have already been installed, as
have several others. To activate and use them, do the following:
1) From the Tools menu, at the top of the ArcMap window, select "Customize".
2) In the Customize dialog, click the Commands tab, then click
"Raster Sample Tool" in the Catergories list.
3) Click and Drag the two commands "Copy Raster Symbology" and
"Paste Raster Symbology" to any toolbar in the ArcMap window. This
will create two new buttons on a tool bar of your choosing.
Unfortunately, the icons for these tools are the same as the
generic cut and paste icons that may already exist in the ArcMap
window - make a mental note of where you park them so you don't
confuse them with other identical toolbar icons.
4) Add rasters to ArcMap, define the symbology for a raster
layer, highlight it in the TOC, and click the Copy Raster
Symbology button.
5) Highlight another raster layer, then click the Paste Raster
symbology button. The symbology will be copied to this layer.
END
|
