polygon to raster conversion

[AlinaYohannan]

I have a 1000x1000 pixel raster, and I created a polygon shapefile with exactly the same extent. When I convert the shapefile to a raster with 4 pixel-values, 0-3, the new raster comes out with an extra column and raw (1001x1001) of value 255. What could cause that, and how can I fix the problem? I need the new raster to be 1000x1000 pixels. I even tried to clip it using the same shapefile, but it didn't work.
Thank you,
Alina

[PeterPierce]

First off, what version are you using?

I've been using 10, and trying to rasterize SSURGO data using the polygon to raster tool. Selecting the values you wish to use (even if it's all of them, or at least that's what has happened to me) in the attribute table will prevent the 1-255 error. Trial and error has also shown that you need to set the priority field to whatever values you wish to have, otherwise it bugs out, and will assign values to your outputs in a seemingly random manner.

Not sure why that happens, but considering that the output of the hydrology toolset produces a similar output when it bugs out, I'm assuming there's a connection in that it will base arrangements in the raster according to topologic conditions (feel free to correct me if I'm wrong).

[AlinaYohannan]

I'm using 10 too, but I had the same problem in 9.3.
I contacted ESRI support center, and I got a very helpul and easy workaround. The fix was from the Environment Settings > Processing extent, where you basicaly choose the original raster for extent and snap raster. I didn't have a problem with the values in the shapefile being output with a different value in the raster. My output had 5 values: the original 4 from the shapefile plus 255, so they didn't range from 1 to 255. And the 255 value was outside the extent of the shapefile. But got it fixed. However, I think I did encounter your problem previously, if I understood you well, so what I did was I saved the raster as an .img, and exported it as an untiled tif using Imagine and the output had the same number of values as the shapefile (although I think they got shuffled).