Warp From File (Data Management)
Performs a transformation on the raster based on a link file, using a polynomial transformation. The link file contains the source and target control points.
Warp is useful when the raster requires a systematic geometric correction that can be modeled with a polynomial. A spatial transformation can invert or remove a distortion by using polynomial transformation of the proper order. The higher the order, the more complex the distortion that can be corrected. The higher orders of polynomial will involve progressively more processing time.
The default polynomial order (1) will perform an affine transformation.
To determine the minimum number of links necessary for a given order of polynomial, use the following formula:
n = (p + 1) (p + 2) / 2
where n is the minimum number of links required for a transformation of polynomial order p. It is strongly suggested to use more than the minimum number of links.
This tool will determine the extent of the warped raster and will set the number of rows and columns to be about the same as in the input raster. Some minor differences may be due to the changed proportion between the output raster's sizes in the x and y directions. The default cell size used will be computed by dividing the extent by the previously determined number of rows and columns. The value of the cell size will be used by the resampling algorithm.
If you choose to define an output cell size in the Environment Settings, the number of rows and columns will be calculated as follows:
columns = (xmax - xmin) / cell size rows = (ymax - ymin) / cell size
You can save your output to BIL, BIP, BMP, BSQ, DAT, GIF, Esri Grid, IMG, JPEG, JPEG 2000, PNG, TIFF, or any geodatabase raster dataset.
When storing your raster dataset to a JPEG file, a JPEG 2000 file, or a geodatabase, you can specify a Compression type and Compression Quality within the Environment Settings.
The input raster dataset.
|Mosaic Layer; Raster Layer|
Output raster dataset.
When storing the raster dataset in a file format, you need to specify the file extension:
When storing a raster dataset in a geodatabase, no file extension should be added to the name of the raster dataset.
When storing your raster dataset to a JPEG file, a JPEG 2000 file, a TIFF file, or a geodatabase, you can specify a compression type and compression quality.
The link file that will be used to warp the raster.
Each row in the input link file should have the following values, each delimited by a TAB:
The geometric transformation type.
The resampling algorithm to be used. The default is NEAREST.
The NEAREST and MAJORITY options are used for categorical data, such as a land-use 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 or MAJORITY 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.
This is a Python sample for the WarpFromFile tool.
import arcpy arcpy.WarpFromFile_management( "\\cpu\data\raster.img", "\\cpu\data\warp_out.tif", "\\cpu\data\gcpfile.txt", "POLYORDER2", "BILINEAR")
This is a Python script sample for the WarpFromFile tool.
##Warp image with signiture file import arcpy arcpy.env.workspace = r"C:/Workspace" arcpy.Warp_management("raster.img", "warp_output.tif", "gcpfile.txt", "POLYORDER2", "BILINEAR")