topic Re: extract by mask fails - possibly corrupting original source raster in ArcGIS Spatial Analyst Questions

extract by mask fails - possibly corrupting original source raster

JustinVreeland — Thu, 08 Dec 2011 12:14:03 GMT

Arc10 is failing to execute extract by mask...sometimes and more recently all the time. Never had this problem before 10, and error codes not helpful.

Using original land use-land cover, 8-bit, discrete, unsigned integer, GRID raster with colormap. This raster covered state of PA. Years ago, I did a majority filter twice and extracted a smaller area I work in - about 10,000 sq mi.

I regularly need to extract smaller landscapes - a few tens of square miles. My masks are shapefiles.

A couple of days ago, I performed an extract successfully, but I misnamed the output file and put it in a bad location, and because catalogue never lets me rename rasters I create (!), I decided to delete it and rerun the extract.

Well, it hasn't worked since except one time when I "re-ran" the analysis in the results window from that session. I've tried the operation on different computers with the same source data, tried rebooting, rerunning the original extract. What I found was extracts from the original data and my statewide majority filter were working until today. Now extract won't work at all as if it's corrupting my source data.

The source raster for the LULC is discrete and the colormap is present, but any time I extract a smaller piece of it, the source becomes continuous and the colormap is absent.

I found some tools to modify these features in "properties" for the new, extracted rasters: add colormap, change change to discrete, but even though no errors show when I run these, the properties aren???t changed, particularly the discrete/continuous.

Even when the extract procedure doesn???t work, it often will still create a grayscale raster, but sometimes it doesn???t. Sometimes it creates spatial reference info and sometimes it doesn???t.

I have no idea what's going on and am not a proficient user of rasters enough to know what could be wrong.

Can anyone help?

thanks,
frustrated in PA!!!

Re: extract by mask fails - possibly corrupting original source raster

JustinVreeland — Thu, 08 Dec 2011 15:25:05 GMT

Here�??s something weird �?? I just tried another extract during and active editing session for the first time.

The old-style results window came up! �?? you know the one that shows a progress bar and gives reports in courier text. And when failing to execute, the dialogue box came back with my inputs.

When not in an editing session, the progress in Arc10 now is shown in that bluish text with the spinning world down in the task bar and a results window pops up only momentarily and the dialogue box never keeps the previous inputs.

Importantly, in the old-style results window this time, I got a little more information that doesn�??t appear in the new results window:

TABLE NAME IS INVALID. This must have something to do with the errors, because it�??ll complete a grayscale raster with no data table.

Re: extract by mask fails - possibly corrupting original source raster

TaylerHamilton — Fri, 24 Feb 2012 19:00:08 GMT

I am having the same issue...extract by mask doesn't work but it still outputs a file in catalogue...it usually is incomplete (not the entire area within the mask) and doesn't have any projection information. I can look at it in catalogue and even add it to arcmap, but since it is incomplete it is useless to me. Also, I can't delete the files for some reason; when I try to arc crashes.

Did you find another way to extract from a raster using a polygon mask?

Re: extract by mask fails - possibly corrupting original source raster

EricRice — Fri, 24 Feb 2012 20:05:45 GMT

Did you find another way to extract from a raster using a polygon mask?

Try the Clip tool.

Regards,
Eric

Re: extract by mask fails - possibly corrupting original source raster

curtvprice — Sat, 25 Feb 2012 02:10:22 GMT

The old-style results window came up! �?? you know the one that shows a progress bar and gives reports in courier text. And when failing to execute, the dialogue box came back with my inputs.

If you want to see it all the time, turn off background geoprocessing. That's the first thing I do when I install Arc 10!

"Table name is invalid" may have to do with how you are naming your output rasters. If they are grids, you need to be very careful to name them with less than 13 characters. My mantra: always start with a letter, and eschew any non-alpha character (except "_") in ArcGIS names and your life will be better.

Re: extract by mask fails - possibly corrupting original source raster

PaulMarangelo — Fri, 05 Feb 2016 14:51:03 GMT

I was searching on "extract by mask"to resolve a similar problem - extracting LULC data for a number of circles so that I could characterize LULC within a certain radius of a point. The extraction would produce a grey scale raster without an attribute table, and it was the attribute table that I needed for my analysis.

By trial and error, I figured out that the extract by mask always fails when the output file name starts with a number. When I used letter characters instead for the output file name, it worked. I don't know why this is so, but I've not had problems since I started naming my output flies with

Re: extract by mask fails - possibly corrupting original source raster

curtvprice — Fri, 19 Feb 2016 00:32:06 GMT

Paul, this because most raster tools use the esri grid format for intermediate results, sometimes even when the output is not grid. The grid naming rules are:

start with a letter
only a-z, 0-9, _ characters
13 character limit

I know it's old school, but I try to follow these rules for all dataset and field names when possible. (Actually field names I try stay under 10 because, shapefiles.)