Build Footprints (Data Management)

License Level:BasicStandardAdvanced

Summary

Computes the footprints for each raster dataset in a mosaic dataset.

Usage

Syntax

BuildFootprints_management (in_mosaic_dataset, {where_clause}, {reset_footprint}, {min_data_value}, {max_data_value}, {approx_num_vertices}, {shrink_distance}, {maintain_edges}, {skip_derived_images}, {update_boundary}, {request_size}, {min_region_size}, {simplification_method}, {edge_tolerance})
ParameterExplanationData Type
in_mosaic_dataset

The mosaic dataset for which the footprints will be calculated.

Mosaic Layer
where_clause
(Optional)

Using SQL, you can define a query or use the Query Builder to build a query.

SQL Expression
reset_footprint
(Optional)

Choose which method to use when redefining the footprints.

  • RADIOMETRYRedefines the shape of the footprint based on a pixel value range. This option is generally used to redefine footprints so that they exclude border areas, which do not define valid data. This is the default.
  • GEOMETRYRedefines the shape of the footprint back to its original geometry.
  • COPY_FROM_SIBLINGWhen using a pan-sharpened raster type, the panchromatic item's footprint will be replaced with the multispectral item's footprint. This occurs with some raster types when the panchromatic and multispectral images do not have identical geometries.
  • NONEThe footprints will not be redefined.

Boolean; String
min_data_value
(Optional)

The lowest pixel value representing valid image data. This value is determined by the bit depth of the raster dataset.

For example, with 8-bit data, the values can range from 0 to 255. A value around 0 represents very dark colors, like black border pixels. When you specify 1, then the only value less than 1 is 0, so all 0 values will be considered invalid data and will be removed from the perimeter of the footprint. If the imagery is compressed using a lossy compression method, then you should define a value slightly greater than 1 to remove all the black pixels. When dark areas, such as shadows, have been incorrectly removed from the footprint, this value should be decreased.

Double
max_data_value
(Optional)

Highest value representing valid data. This value is determined by the bit depth of the raster dataset.

For example, with 8-bit data, the values can range from 0 to 255. A value around 255 represents very bright colors, such as white clouds and snow. If you specify 245, then all values between 246 and 255 will be removed from the perimeter of the footprint.

Double
approx_num_vertices
(Optional)

Approximate number of vertices with which the new footprint polygon will be created.

The minimum value is 4 and the maximum value is 10,000. The greater this value, the more accurate and irregular the polygon and the longer the processing time.

A value of -1 will show all the vertices in the footprint, therefore, your polygon footprint will not be generalized.

Long
shrink_distance
(Optional)

Distance value specified in the units of the mosaic dataset's coordinate system by which the overall polygon will be reduced in size.

Shrinking of the polygon is used to counteract effects of lossy compression, which causes edges of the image to overlap into NoData areas.

Double
maintain_edges
(Optional)

Use this parameter when using raster datasets that have been tiled and are butt joined (or line up along the seams with little to no overlap).

  • NO_MAINTAIN_EDGESAll footprints will be altered, regardless of their neighboring footprints. This is the default.
  • MAINTAIN_EDGESAn analysis of the image edges is performed so that the sheet edges are not removed.
Boolean
skip_derived_images
(Optional)

Adjust the footprints for derived images, such as service overviews.

  • SKIP_DERIVED_IMAGESDerived images, such as service overviews, will not be adjusted. This is the default.
  • NO_SKIP_DERIVED_IMAGESFootprints of any derived images will be adjusted along with the base images.
Boolean
update_boundary
(Optional)

Generates or updates the boundary polygon of a mosaic dataset. By default, the boundary merges all the footprint polygons to create a single boundary representing the extent of the valid pixels.

  • UPDATE_BOUNDARYThe boundary will be generated or updated. This is the default.
  • NO_BOUNDARYThe boundary will not be generated or updated.
Boolean
request_size
(Optional)

The size to which the raster will be resampled when it is examined using this tool. The value (such as 2,000) defines the dimension using rows and columns.

You can increase or decrease this value based on the complexity of your raster data. Greater image resolution provides more detail in the raster dataset and thereby increases the processing time.

A value of -1 will not resample the footprint, therefore, it will compute the footprint at the native pixel size.

The request size cannot be greater than the raster contained by the footprints. If this is the case, then the value will automatically be the same as the size of the raster.

Long
min_region_size
(Optional)

Determines a filter used to remove holes created in the footprint.

This value is specified in pixels, and it is directly related to the Request Size, not to the pixel resolution of the source raster.

Long
simplification_method
(Optional)

The simplification will reduce the number of vertices, since dense footprints can affect display performance.

Choose which method to use in order to simplify the footprints.

  • NONENo simplification method will be implemented. This is the default.
  • CONVEX_HULLThe minimum bounding geometry for each footprint will be used to simplify the footprint.
  • ENVELOPEThe envelope of each mosaic dataset item will provide the simplified footprint.
String
edge_tolerance
(Optional)

The tolerance value is specified in the units of the mosaic dataset's coordinate system below which the footprint will snap to the sheet edge. This is used when maintain_edges is set to MAINTAIN_EDGES.

By default, the value is empty for which the tolerance is computed based on the pixel size corresponding to the requested resampled raster.

A value of -1 will compute the tolerance using the average pixel size of the mosaic dataset.

Double

Code Sample

BuildFootprints example (Python window)

This is a Python sample for the BuildFootprints tool.

import arcpy
arcpy.BuildFootprints_management(
     "c:/data/Footprints.gdb/md", "#","RADIOMETRY",
     "1", "254", "25", "0", "#", "SKIP_DERIVED_IMAGES", 
     "UPDATE_BOUNDARY", "#", "#", "CONVEX_HULL")
BuildFootPrints example 2 (stand-alone window)

This is a Python script sample for the BuildFootprints tool.

# Build Footprint by setting the valid pixel value range from 1 to 254
# Allow 25 vertices to be used to draw a single footprint polygon
# Skip the overviews image
# Build new boundary afterwards
# Build footprints based on minimum bounding geometry

import arcpy
arcpy.env.workspace = "C:/Workspace"

    
mdname = "Footprints.gdb/md"
query = "#"
method = "RADIOMETRY"
minval = "1"
maxval = "254"
nvertice = "25"
shrinkdis = "0"
maintainedge = "#"
skipovr = "SKIP_DERIVED_IMAGES"
updatebnd = "UPDATE_BOUNDARY"
requestsize = "#"
minregsize = "#"
simplify = "#"

arcpy.BuildFootprints_management(
     mdname, query, method, minval, maxval, nvertice, shrinkdis,
     maintainedge, skipovr, updatebnd, requestsize, minregsize, 
     simplify)

Environments

Related Topics

Licensing Information

ArcGIS for Desktop Basic: No
ArcGIS for Desktop Standard: Yes
ArcGIS for Desktop Advanced: Yes
11/18/2013