Create an outline of a raster grid

ShaneCarey

Hi,

I have a raster grid and I need to create a outline from the grid, some areas have No data and I was going to try create an outline using contour, but this will not work for areas of No data.

Any ideas would be appreciated,

Cheers
Thanks

JamesCrandall

You can use the Extent of the raster to get the lower-left, lower-right, upper-left, and upper-right points and just add these to a new polyline or polygon feature class.

inputRaster = r"C:\MyRaster"
desc = arcpy.Describe(inputRaster)
ext = desc.extent

ll = ext.lowerLeft
ul = ext.upperLeft
lr = ext.lowerRight
ur = ext.upperRight

arcpy.CreateFeatureclass_management(r"C:\Documents\ArcGIS\Default.gdb","extentoutput", "POLYGON")

outFC = r"C:\Documents\ArcGIS\Default.gdb\extentoutput"

array = arcpy.Array([ll, ul, ur, lr])
pg = arcpy.Polygon(array)

with arcpy.da.InsertCursor(outFC, ["SHAPE@"]) as cursor:
    cursor.insertRow([pg])

Edit:  If you want it as a polyline output FC, then be sure to add the starting point at the end to "close" the polyline as a bounding box:

inputRaster = r"C:\MyRaster"
desc = arcpy.Describe(inputRaster)
ext = desc.extent

ll = ext.lowerLeft
ul = ext.upperLeft
lr = ext.lowerRight
ur = ext.upperRight

arcpy.CreateFeatureclass_management(r"C:\Documents\ArcGIS\Default.gdb","extentoutput", "POLYLINE")

outFC = r"C:\Documents\ArcGIS\Default.gdb\extentoutput"

array = arcpy.Array([ll, ul, ur, lr, ll])
pl = arcpy.Polyline(array)

with arcpy.da.InsertCursor(outFC, ["SHAPE@"]) as cursor:
    cursor.insertRow([pl])