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Have you tried reclassifying the DEM before hillshading (that's a word right)? You might be able to make areas you want not shaded some index value (-999) and then remove with reclass later. The hillshade assigns values to every cell I believe so doing it before the hillshade is probably best bet. On Wed, Mar 25, 2015 at 3:25 PM, Jarlath O'Neil-Dunne < [log in to unmask]> wrote: > …and of course I meant to say “hillshade” not “hillside” - autocorrect is > not GIS savvy! > — > Jarlath O’Neil-Dunne > University of Vermont | Spatial Analysis Lab > > > > On Mar 25, 2015, at 3:23 PM, Jarlath O'Neil-Dunne < > [log in to unmask]> wrote: > > I do large hillside from massive LiDAR datasets using the Image Analysis > tools. Hillshade in less than a second and minimal storage space. > > http://resources.arcgis.com/en/help/main/10.2/index.html#//009t0000007r000000 > — > Jarlath O’Neil-Dunne > University of Vermont | Spatial Analysis Lab > > > > On Mar 25, 2015, at 3:14 PM, Christi Ludlow Townsend <[log in to unmask]> > wrote: > > Hi, > > I am creating a global hillshade file from the GLSDEM. I've mosaiced the > tiles into four hemisphere-wide rasters (16-bit signed integer). I am > running each mosaic through the ESRI 10.2 Hillshade tool which outputs > 8-bit unsigned files. There are 2 issues: > > 1) The output files are still huge (20GB or something ridiculous). I have > tried tif, jp2 and img but none of them help with file size. > > 2) I'd like to remove or make transparent the non-shaded areas. ESRI > directions say to use a reclassify or extract by attribute to separate > non-zero values. Thing is, most of the resulting hillshade pixel values > are non-zero so not much area would be made transparent by creating such a > file. > > Any ideas? > > It seems that much of the support documentation assumes you want to use > mosaic datasets which I cannot in this case. > > Many thanks, > > Christi > ------------------------------------------------------------------------- > This list (NEARC-L) is an unmoderated discussion list for all NEARC Users. > > If you no longer wish to receive e-mail from this list, you can remove > yourself by going to http://listserv.uconn.edu/nearc-l.html. > > > > ------------------------------------------------------------------------- > This list (NEARC-L) is an unmoderated discussion list for all NEARC Users. > > If you no longer wish to receive e-mail from this list, you can remove > yourself by going to http://listserv.uconn.edu/nearc-l.html. > ------------------------------------------------------------------------- This list (NEARC-L) is an unmoderated discussion list for all NEARC Users. If you no longer wish to receive e-mail from this list, you can remove yourself by going to http://listserv.uconn.edu/nearc-l.html.