Raster map is a map which contains raster data in pixels. Similar to vector map (polygon), raster map has also attributes. This attribute can be merged to other map by using Mosaic to new Raster function in Arc Toolbox. Of course you should classify your raster map first in order to see the attribute (right click and chose open attribute table to see the attribute).
If the map has not been classified yet, use reclassify function to classify the attribute. In this example, the third class will be merged with other raster map which contains only third class. This inserted class will change the raster data of the same class in previous raster class. But, the other classes also change because of the inserted class replace the previous class data. Table below shows the inserted raster which can be extract from other raster map using extract by mask function (see previous post).
The most important thing in using mosaic to new raster toolbox is the order first and second raster map. See the arrangement of input raster maps below. Since kind of mode of operator for this filling was “LAST”, the last raster map in the input raster will replace the previous raster data. If you do not properly place the order of input raster, the result will the same as previous (inserting process is fail).
The other important parameter is number of bands which is usually “1” because there is no band in the example raster map. Fill folder location and file output name (I don’t know why folder and name of file is placed in different filling location). Figure below shows that class “3” has change because of inserting from the other raster map. In addition, not only class “3” but the other classes also change.