topic Re: Batch process to find nodata values = 0 in Python Questions

Batch process to find nodata values = 0

NathanWest1 — Wed, 23 Apr 2014 14:33:22 GMT

I am wondering if it is possible to query a directory, returning results of any raster that has no data values of 0. I have been building mosaics, making the nodata values = 1. However, some have been built with nodata values= 0. Is there a way to find these 0 values without checking each one individually?

Thanks for any and all input.

Re: Batch process to find nodata values = 0

JamesCrandall — Sat, 11 Dec 2021 16:41:39 GMT

Check if the ANYNODATA or ALLNODATA properties of GetRasterPorperties_management will do what you want:

http://resources.arcgis.com/en/help/main/10.1/index.html#//0017000000m7000000

Here is an exmple of running thru the Default.gdb on my system and reporting the raster name and ANYNODATA value


ws = r'H:\Documents\ArcGIS\Default.gdb'
arcpy.env.workspace = ws
rasters = arcpy.ListRasters()
for raster in rasters:
    nodatval = arcpy.GetRasterProperties_management(raster, "ANYNODATA")
    print str(raster) + " NoData = " + str(nodatval)
    
sys.exit()

Re: Batch process to find nodata values = 0

MathewCoyle — Sat, 11 Dec 2021 16:41:42 GMT

If they are single band rasters this should work.

desc = arcpy.Describe(raster)
desc.noDataValue

Re: Batch process to find nodata values = 0

NathanWest1 — Wed, 23 Apr 2014 15:58:35 GMT

They are multiple bands. Neither of the above seemed to work. Is there a way to query rasters for pixel values of 0 instead of going the nodata route?

Re: Batch process to find nodata values = 0

NathanWest1 — Sat, 11 Dec 2021 16:41:44 GMT

Check if the ANYNODATA or ALLNODATA properties of GetRasterPorperties_management will do what you want:

http://resources.arcgis.com/en/help/main/10.1/index.html#//0017000000m7000000

Here is an exmple of running thru the Default.gdb on my system and reporting the raster name and ANYNODATA value
ws = r'H:\Documents\ArcGIS\Default.gdb'
arcpy.env.workspace = ws
rasters = arcpy.ListRasters()
for raster in rasters:
    nodatval = arcpy.GetRasterProperties_management(raster, "ANYNODATA")
    print str(raster) + " NoData = " + str(nodatval)
    
sys.exit()

This seems to give me a "nodata = 1" no matter whether the nodata values are 0 or 1. is there a way to query for pixel value? If i could query for pixel values of 0 then that would solve my problems competely. Thanks for the input!

Re: Batch process to find nodata values = 0

MathewCoyle — Wed, 23 Apr 2014 16:10:28 GMT

If they are multiple bands what are your no data values you are looking for? 0,0,0?

Re: Batch process to find nodata values = 0

NathanWest1 — Wed, 23 Apr 2014 16:16:26 GMT

If they are multiple bands what are your no data values you are looking for? 0,0,0?

yes. and would it have to be done from within a GDB? Thanks!

Re: Batch process to find nodata values = 0

MathewCoyle — Sat, 11 Dec 2021 16:41:47 GMT

You can try searching each band. And no it shouldn't matter if it is in a GDB or not, but I can't speak to every raster format possible. I'm sure some formats don't support this. Give this a try, assuming you are dealing with bands 1,2,3.

bands = ['Band_1', 'Band_2', 'Band_3']
for band in bands:
    desc = arcpy.Describe(os.path.join(raster, band))
    desc.noDataValue