Geoprocessing tool reference > Data Management toolbox > Projections and Transformations toolset > Tools
Project Raster (Data Management) |
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Release 9.2
Last modified November 29, 2010 |
Print all topics in : "Tools" |
Transforms the raster dataset from one projection to another.
Learn more about how Project Raster works
Usage tips
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The coordinate system defines how your raster data is projected.
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This tool guarantees that the error is less than half a pixel.
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You are able to choose a preexisting spatial reference, import it from another dataset, or create a new one.
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You may want to change the coordinate system so your data is all in the same projection.
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You can save your output to GRID, IMG, TIFF, personal geodatabase, file geodatabase, or ArcSDE geodatabase.
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Projects a raster dataset into a new spatial reference using a bilinear interpolation approximation method, which projects pixels on a coarse mesh grid and uses bilinear interpolation in between the pixels.
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The NEAREST option, which performs a nearest neighbor assignment, is the fastest of the four interpolation methods. It is primarily used for categorical data, such as a land use classification, because it will not change the cell values. Do not use NEAREST for continuous data, such as elevation surfaces.
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The BILINEAR option, bilinear interpolation, determines the new value of a cell based on a weighted distance average of surrounding cells. The CUBIC option, cubic convolution, determines the new cell value by fitting a smooth curve through the surrounding points. These are most appropriate for continuous data and may cause some smoothing; also, cubic convolution may result in the output raster containing values outside the range of the input raster. It is not recommended that BILINEAR or CUBIC be used with categorical data because the cell values may be altered.
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The cells of the raster dataset will be square and of equal area in map coordinate space, although the shape and area a cell represents on the surface of the earth will never be constant across a raster. This is because no map projection can preserve both shape and area simultaneously. The area represented by the cells will vary across the raster. Therefore, the cell size and the number of rows and columns in the output raster may change.
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Always specify an output cell size, unless you are projecting between spherical (latitude/longitude) coordinates and a planar coordinate system where you don't know what an appropriate cell size would be.
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The default cell size of the output raster is determined from the projected cell size at the center of the output raster. This is usually also the intersection of the central meridian and latitude of true scale and is the area of least distortion. The boundary of the input raster is projected, and the minimum and maximum extents dictate the size of the output raster. Each cell is projected back to the input coordinate system to determine the cell's value.
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The geographic transformation is an optional parameter when the input and output coordinate systems have the same datum. If the the input and output datum are different, a geographic transformation needs to be specified.
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When you are using the tool's command in the command line window, you may need to press F8 when entering a variable with which you need help. You may want to do this when entering a spatial reference.
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CLARKE 1866 is the default spheroid if it is not inherent to the projection (such as NEWZEALAND_GRID) or another is specified with the SPHEROID subcommand.
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The following environments affect this tool: current workspace, scratch workspace, output extent, output CONFIG keyword, pyramid, raster statistics, compression, and tile size.
Command line syntax
An overview of the Command Line window
ProjectRaster_management <in_raster> <out_raster> <out_coor_system> {NEAREST | BILINEAR | CUBIC} {cell_size} <geographic_transform> {Registration_Point} {in_coor_system}
| Parameter | Explanation | Data Type |
| <in_raster> |
The input raster dataset. |
Composite Geodataset |
| <out_raster> |
The output raster dataset to be created. When storing a raster dataset in a geodatabase, no file extension is required. When storing the raster dataset in a file format, you need to specify the file extension: .img for an ERDAS IMAGINE file, .tif for TIFF, or no extension for GRID. |
Raster Dataset |
| <out_coor_system> |
The coordinate system for the geometry column. The default is the same as in the Spatial Reference Settings environment. To add this variable, press F8 or right-click and click Insert Variable. |
Spatial Reference |
| {NEAREST | BILINEAR | CUBIC} |
The resampling algorithm to be used. The default is NEAREST.
The NEAREST option is used for categorical data, such as a landuse classification. The NEAREST option is the default since it is the quickest and also because it will not change the cell values. Do not use NEAREST for continuous data, such as elevation surfaces. The BILINEAR option and the CUBIC option are most appropriate for continuous data. It is not recommended that BILINEAR or CUBIC be used with categorical data because the cell values may be altered. |
String |
| {cell_size} |
The cell size for the output raster dataset. The default cell size is the cell size of the selected raster dataset. |
Analysis Cell Size |
| <geographic_transform> |
The transformation method used between two geographic systems or datums. For more information on geographic transformations, see Geographic transformation methods. The geographic transformation is optional when the input and output coordinate systems have the same datum. If the input and output datum are different, a geographic transformation needs to be specified. |
String |
| {Registration_Point} |
The x and y coordinates (in the output space) used for pixel alignment. |
Point |
| {in_coor_system} |
The coordinate system of the input raster dataset. |
Coordinate System |
Command line example
ProjectRaster c:\test_data\dams C:\test_data\dams_projected 'Coordinate Systems\Projected Coordinate Systems\Utm\Nad 1927\NAD 1927 UTM Zone 14N.prj' BILINEAR 30 NAD_1927_To_NAD_1983_NADCON '100, 100'
Scripting syntax
About getting started with writing geoprocessing scripts
ProjectRaster_management (in_raster, out_raster, out_coor_system, resampling_type, cell_size, geographic_transform, Registration_Point, in_coor_system)
| Parameter | Explanation | Data Type |
| in_raster (Required) |
The input raster dataset. |
Composite Geodataset |
| out_raster (Required) |
The output raster dataset to be created. When storing a raster dataset in a geodatabase, no file extension is required. When storing the raster dataset in a file format, you need to specify the file extension: .img for an ERDAS IMAGINE file, .tif for TIFF, or no extension for GRID. |
Raster Dataset |
| out_coor_system (Required) |
The coordinate system for the geometry column. The default is the same as in the Spatial Reference Settings environment. To add this variable, press F8 or right-click and click Insert Variable. |
Spatial Reference |
| resampling_type (Optional) |
The resampling algorithm to be used. The default is NEAREST.
The NEAREST option is used for categorical data, such as a landuse classification. The NEAREST option is the default since it is the quickest and also because it will not change the cell values. Do not use NEAREST for continuous data, such as elevation surfaces. The BILINEAR option and the CUBIC option are most appropriate for continuous data. It is not recommended that BILINEAR or CUBIC be used with categorical data because the cell values may be altered. |
String |
| cell_size (Optional) |
The cell size for the output raster dataset. The default cell size is the cell size of the selected raster dataset. |
Analysis Cell Size |
| geographic_transform (Required) |
The transformation method used between two geographic systems or datums. For more information on geographic transformations, see Geographic transformation methods. The geographic transformation is optional when the input and output coordinate systems have the same datum. If the input and output datum are different, a geographic transformation needs to be specified. |
String |
| Registration_Point (Optional) |
The x and y coordinates (in the output space) used for pixel alignment. |
Point |
| in_coor_system (Optional) |
The coordinate system of the input raster dataset. |
Coordinate System |
Data types for geoprocessing tool parameters
Script example
# Create the geoprocessing object
import arcgisscripting
gp = arcgisscripting.create()
gp.workspace = "c:/Data"
# Set the spatial reference and registration variables
cs = "C:/ArcGIS/Coordinate Systems/Geographic Coordinate Systems/North America/North American Datum 1983.prj"
RegistrationPoint = '100 100'
gp.ProjectRaster_management("Redlands.tif", "Redlands_projected.tif", cs, "BILINEAR", 30, "NAD_1927_To_NAD_1983_NADCON", RegistrationPoint)