Mosaic Rasters to a Seamless Raster

Step 1 Create Mosaic Raster from rasters

This actually can be further divided into two steps: 1) create a mosaic raster dataset; 2) add rasters to mosaic raster dataset. A lot of details should be noticed when working on these two seemingly straightforward steps. The following links redirect you to webpages that are showing how to perform the operations step by step ( if you have any problems, feel free to leave comments on this post):

http://resources.arcgis.com/en/help/main/10.1/index.html#/Creating_a_mosaic_dataset_containing_raster_data_from_multiple_dates/009t000000v1000000/

http://gishelper.com/resources/USING%20A%20MOSAIC%20DATASET%20TO%20ADD%20A%20HILLSHADE%20TO%20A%20SCANNED%20MAP.pdf

Possible problems that you would come across during your operation can be solved:

http://blogs.esri.com/esri/supportcenter/2011/10/07/imagery-not-displaying-in-your-mosaic-dataset/


Step 2 Create seamless Mosaic Raster

https://www.youtube.com/watch?v=qJHCbEVbMv0

For latest version of ArcGIS for DESKTOP, code as follows works well:
Con(IsNull("myraster"), FocalStatistics("myraster", NbrRectangle(2,2, "CELL"), "MEAN"), "myraster")