Polygon to Raster (Conversion)

Summary

Converts polygon features to a raster dataset.

Learn how the Polygon to Raster tool works

Usage

• Any feature class (geodatabase, shapefile or coverage) containing polygon features can be converted to a raster dataset.

• The input field type determines the type of output raster. If the field is integer, the output raster will be integer; if it is floating point, the output will be floating point.

  If the input field contains string values, the output raster will contain an integer value field and a string field.

• This tool is a complement to the Raster to Polygon tool, which convert a raster to a polygon feature class.

• This tool provides greater control over the assignment of cell values when more than one feature is present in an output cell than the Feature to Raster tool.

• If "bleeding" or stripes occur in the output raster then use the Check Geometry and Repair Geometry tools to correct the input feature data.

• When converting overlapping polygons, you may want the polygons with the smallest area to be assigned to a cell. An easy way to do this is to add an additional field to the input feature class and calculate it to the inverse area of the polygons, then use this field as the Priority Field when running this tool.

Syntax

PolygonToRaster_conversion (in_features, value_field, out_rasterdataset, {cell_assignment}, {priority_field}, {cellsize})

Parameter	Explanation	Data Type
in_features	The polygon input feature dataset to be converted to a raster.	Feature Layer
value_field	The field used to assign values to the output raster. It can be any field of the input feature dataset's attribute table.	Field
out_rasterdataset	The output raster dataset to be created. When not saving to a geodatabase, specify .tif for a TIFF file format, .img for an ERDAS IMAGINE file format, or no extension for a GRID raster format.	Raster Dataset
cell_assignment (Optional)	The method to determine how the cell will be assigned a value when more than one feature falls within a cell. CELL_CENTER —The polygon which overlaps the center of the cell yields the attribute to assign to the cell. MAXIMUM_AREA —The single feature with the largest area within the cell yields the attribute to assign to the cell. MAXIMUM_COMBINED_AREA — If there is more than one feature in a cell with the same value, the areas of these features will be combined. The combined feature with the largest area within the cell will determine the value to assign to the cell.	String
priority_field (Optional)	This field is used to determine which feature should take preference over another feature with the same value in the Value field.	Field
cellsize (Optional)	The cell size for the output raster dataset. The default cell size is the shortest of the width or height of the extent of the input feature dataset, in the output spatial reference, divided by 250.	Analysis Cell Size

Code Sample

PolygonToRaster example 1 (Python window)

Converts polygon features to a raster dataset.

import arcpy
from arcpy import env
env.workspace = "c:/data"
arcpy.PolygonToRaster_conversion("ca_counties.shp", "NAME", 
                                 "c:/output/ca_counties.img", 
                                 "MAXIMUM_AREA", "MALES", 0.25)

PolygonToRaster example 2 (stand-alone script)

Converts polygon features to a raster dataset.

# Name: PolygonToRaster_Ex_02.py
# Description: Converts polygon features to a raster dataset.
# Requirements: ArcInfo

# Import system modules
import arcpy
from arcpy import env

# Set environment settings
env.workspace = "C:/data"

# Set local variables
inFeatures = "ca_counties.shp"
valField = "NAME"
outRaster = "c:/output/ca_counties"
assignmentType = "MAXIMUM_AREA"
priorityField = "MALES"
cellSize = 0.5

# Execute PolygonToRaster
arcpy.PolygonToRaster_conversion(inFeatures, valField, outRaster, 
                                 assignmentType, priorityField, cellSize)

Environments

Compression, Current Workspace, Output Coordinate System, Extent, Pyramid, Scratch Workspace, Cell Size, Snap Raster

Licensing Information

ArcView: Requires Spatial Analyst or 3D Analyst

ArcEditor: Requires Spatial Analyst or 3D Analyst

ArcInfo: Yes