Extract Scanned Polygons (Conversion Tools)

Summary

Generates polygon features from scanned images.

Illustration

Extract Scanned Polygons tool illustration

Usage

The raster must be classified into two classes (binary image) in order to extract features.
Results may be determined by the state of the scanned map at the time of the extraction. To eliminate noise and unwanted pixels it is sometimes necessary to modify the image prior to the extraction of features.
The parameters control which cells are extracted as well as the amount of generalization and smoothing that is applied to the output polygon features.

Label	Explanation	Data type
Input Scanned Map Image	The input raster dataset. The raster must be classified into two classes (binary image).	Raster Layer
Foreground Value	The foreground value that represents the raster cells that will be extracted to line features.	Long
Output Polygon Features	The output feature class that will contain the converted polygons that represent the outline of the raster cells.	Feature Class
Compression Tolerance (Optional)	Simplifies lines by removing vertices based on the specified tolerance. Higher compression tolerance values will result in fewer vertices and greater deviation from the original line shape. The compression tolerance indicates the degree of generalization, not map or pixel units.	Double
Apply Smoothing (Optional)	Specifies whether smoothing will be applied to polygon features during extraction. Checked—Smoothing will be applied to the extracted polygon features. Unchecked—Smoothing will not be applied to the extracted polygon features.	Boolean
Smoothing Weight (Optional)	The intensity of smoothing. Higher smoothing weight values produce smoother lines but may cause the output to deviate from the original shape. The smoothing weight value is not a specific map or pixel unit.	Double
Hole Size (Optional)	If a hole's diagonal length is less than or equal to the specified distance, it will be treated as part of the raster line when extracted. This parameter allows you to ignore holes (small gaps fully enclosed by foreground pixels) in raster lines during extraction. Holes often result from poor source quality or scanning errors.	Long

arcpy.conversion.ExtractScannedPolygons(in_raster, foreground_value, out_polygons, {compression}, {smoothing}, {smoothing_weight}, {hole_size})

Name	Explanation	Data type
in_raster	The input raster dataset. The raster must be classified into two classes (binary image).	Raster Layer
foreground_value	The foreground value that represents the raster cells that will be extracted to line features.	Long
out_polygons	The output feature class that will contain the converted polygons that represent the outline of the raster cells.	Feature Class
compression (Optional)	Simplifies lines by removing vertices based on the specified tolerance. Higher compression tolerance values will result in fewer vertices and greater deviation from the original line shape. The compression tolerance indicates the degree of generalization, not map or pixel units.	Double
smoothing (Optional)	Specifies whether smoothing will be applied to polygon features during extraction. `SMOOTHING`—Smoothing will be applied to the extracted polygon features. `NO_SMOOTHING`—Smoothing will not be applied to the extracted polygon features.	Boolean
smoothing_weight (Optional)	The intensity of smoothing. Higher smoothing weight values produce smoother lines but may cause the output to deviate from the original shape. The smoothing weight value is not a specific map or pixel unit.	Double
hole_size (Optional)	If a hole's diagonal length is less than or equal to the specified distance, it will be treated as part of the raster line when extracted. This parameter allows you to ignore holes (small gaps fully enclosed by foreground pixels) in raster lines during extraction. Holes often result from poor source quality or scanning errors.	Long

Code sample

ExtractScannedPolygons example 1 (Python window)

The following sample demonstrates the use of this tool in the Python window:

import arcpy
arcpy.env.workspace = 'C:/data'
arcpy.conversion.ExtractScannedPolygons(
    in_raster="Scanned_Map_Image", foreground_value=[1],
    out_polygons=r"C:\data\output.gdb\Extracted_Polygons", compression=0.025,
    smoothing=True, smoothing_weight=3, hole_size=0
)

ExtractScannedPolygons example 2 (stand-alone script)

Extracts polygons from a scanned map image

# Name: ExtractScannedPolygonsEx_02.py
# Description: Extracts polygons from a scanned map image
# Requirements: None

# Import system modules
import arcpy
# Set environment settings
arcpy.env.workspace = 'c:/data'

# Set Local Variables
inRaster = "c:/data/ScannedImage"
foregroundValue = [1]
outPolygons = 'c:/data/output.gdb/Extracted_Polygons'
compression = 0.025
smoothing = True
smoothingWeight = 3
holeSize = 0

# Run ExtractScannedPolygons
arcpy.conversion.ExtractScannedPolygons(
    inRaster, foregroundValue, outPolygons, compression, smoothing,
    smoothingWeight, holeSize
)

Environments

Current Workspace, Extent, Output Coordinate System, Geographic Transformations, Output CONFIG Keyword, Output XY Domain, Output Z Domain

Licensing information

Basic: No
Standard: No
Advanced: Yes