topic Re: extracting values from raster in ArcGIS Spatial Analyst Questions

extracting values from raster

ChristianAndersen — Thu, 01 Aug 2013 12:00:46 GMT

Hi all,

Its been some years ago since I worked with rasterdata for real, so I have to brush up my knowledge on this subject. Hope you guys is able to help. 🙂

I have a raster file (img) containing gridcells with values represent floodvalues (0,1 representing 10 cm water on the surface). I want to extract the cells with more than 10 cm water on the surface. I´ve tried with the extract by attributes, but somehow there isn´t a attribute to select?! If I use the info selection on one cell I get the stretched value and the pixel value (which is equel to the amount of water) so there must be a value somewhere that I should be able to extract on.

What am I missing? Can somebody please guide me in the right direction?

Thanks in advance

Christian

Re: extracting values from raster

MarkBoucher — Thu, 01 Aug 2013 13:24:49 GMT

Have you tried the Con() function in the raster calculator?
http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#/Building_expressions_in_Raster_Calculator/009z000000zn000000/

Re: extracting values from raster

DanPatterson_Retired — Thu, 01 Aug 2013 15:54:23 GMT

are you using the raster calculator (map algebra in ArcToolbox)? if it is an integer grid you want to query for values > 1