topic Re: Separate raster bands in python toolbox in Python Questions

Separate raster bands in python toolbox

BenLeslie1 — Sun, 12 Dec 2021 02:06:16 GMT

I have a python script that, as part of the code, separates raster bands and then uses Con to identify black pixels; like this:

MyRaster = r"MyRaster.tif"
redband = MyRaster + "\Band_1"
greenband = MyRaster + "\Band_2"
blueband = MyRaster + "\Band_3"
BlackPixels = Con (((Raster(redband)==0 & (Raster(greenband)==0..................

However, I'm now trying to make this script into a python toolbox but the bands are not being recognised; like this:

def getParameterInfo(self):
     inRaster = arcpy.Parameter(
          displayName="input raster",
          name="inraster",
          datatype=["GPRasterLayer","DERasterDataset"],
          parameterType="Required",
          direction="Input")
.......

     return [inRaster]

     def execute (self,parameters,messages):
          MyRaster = parameters[0].valueAsText
          redband = MyRaster + "/Band_1"
          greenband = MyRaster + "/Band_2"
          blueband = MyRaster + "/Band_3"
          BlackPixels = Con (((Raster(redband)==0 & (Raster(greenband)==0..................

I get following message

RuntimeError: ERROR 000732: Input Raster: Dataset MyRaster.tif/Band_1 does not exist.

What am I doing wrong?

Re: Separate raster bands in python toolbox

DanPatterson_Retired — Thu, 03 Mar 2016 11:04:59 GMT

print the path to see what is returned

Re: Separate raster bands in python toolbox

BenLeslie1 — Thu, 03 Mar 2016 11:09:58 GMT

messages.addMessage("MyRaster = " + MyRaster)

--> MyRaster = MyRaster.tif

this is what I expect. maybe my expectations are wrong.

Re: Separate raster bands in python toolbox

DanPatterson_Retired — Thu, 03 Mar 2016 11:27:01 GMT

Since it is a multiband raster, you will have to split it by band or access it by band, if you need to perform the con statement in your execute section, confirm that you can do it manually first, then use the results window.

Re: Separate raster bands in python toolbox

BenLeslie1 — Thu, 03 Mar 2016 12:08:45 GMT

got ya.

path = arcpy.Describe(MyRaster).path

redband = path + "\\" + MyRaster + "\\Band_1"

Re: Separate raster bands in python toolbox

Luke_Pinner — Thu, 03 Mar 2016 22:48:56 GMT

Couple of ways to do this easily in the answers to the following GIS Stack Exchange question:

python - Access individual bands and use them in map algebra - Geographic Information Systems Stack Exchange

I'll throw this in for future reference for other users as the band names are not always guaranteed to be "Band_[1-N]"