USGS: ISIS warp Application Documentation

ISIS Application Documentation

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Warp an image using a Control Network

Overview

Parameters

Example 1

Example 2

Example 3

Description

This application applies a geometric warp to an image using a user supplied Control Network. The Control Network consists of the input (FROM) cube and a second cube for which image-to-image Control Points are measured. Programs, such as coreg, can be used to generate the Control Network file for level1 or level2 cubes.

The Control Measures of the FROM cube are fit to the corresponding Control Measures of the second cube in the Control Network file using a weighted or non-weighted least squares fit to a polynomial of degree N, where N is specified by the DEGREE parameter.

With weighted least squares fit, specific pixel movement (input to output location) is based on Control Point distances from a given pixel. That is, Control Points closest to a given input pixel will have greater weight (influence) on the computed output location than Control Points furthest from the input pixel. With non-weighted least squares fit, all Control Points will have equal weight toward influencing individual pixel movement.

Related Applications to Previous Versions of ISIS

This program replaces the following applications existing in previous versions of ISIS:

random
warp2

History

Kay Edwards	1987-06-08	Original version
Jeff Anderson	2004-06-18	Converted to Isis 3.0
Elizabeth Miller	2005-10-11	Finished documentation and code
Elizabeth Miler	2005-11-03	Added appTest
Jacob Danton	2006-04-05	Added error checking for control networks
Steven Lambright	2007-06-22	Fixed typo in user documentation
Steven Lambright	2008-05-13	Removed references to CubeInfo
Stacy Alley	2008-12-19	Updating documentation and adding examples
Janet Barrett	2010-07-30	Changed CONTROL parameter name to CNET.
Kris Becker	2011-10-07	Updated documentation with review and contributions from Chris Isbell and Annie Howington.
Jacob Cain	2022-11-22	Changed CUBE type to cube. Fixes #4780.

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File Modified: 02/21/2025 19:28:14

Parameter Groups

Files

Name	Description
FROM	Input cube to warp
TO	Output cube
CNET	Control Network file

Warp parameters

Name	Description
DEGREE	Order of polynomial
WEIGHTED	Weight the Control Points using distance
OSIZE	Output cube size
CUBE	Match Output cube to this Cube's Size
ONL	Output Lines
ONS	Output Samples

Interpolation

Name	Description
INTERP	Type of interpolation

Files: FROM

Description

Specify the input cube to be warped. This can be a level1 or level2 cube. All bands within the cube will be warped unless a specific band is specified.

Type	cube
File Mode	input
Filter	*.cub

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Files: TO

Description

This new output cube will contain the results of the warp processing. It will either be a single-band or multi-band cube based on the input bands specified in the FROM cube.

Type	cube
File Mode	output

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Files: CNET

Description

This input Control Network file contains image-to-image Control Points that will be used to apply the warp transformation. Exactly two images are allowed in this Control Network, one of which must be the FROM cube. This file is typically generated by the coreg application.

Type	filename
File Mode	input
Filter	*.net

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Warp parameters: DEGREE

Description

The order of the polynomial to be used in the linear regression fit. Higher order polynomial requires more numerous Control Points.

Type	integer
Default	1
Minimum	1 (inclusive)

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Warp parameters: WEIGHTED

Description

With this option selected (default), specific pixel movement (input to output location) is based on Control Point distances from the pixel. That is, Control Points closest to a given input pixel will have greater weight (influence) on the computed output location than Control Coints furthest from the input pixel. Without this selection, all Control Points will have equal weight toward influencing individual pixel movement.

Type	boolean
Default	true

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Warp parameters: OSIZE

Description

This option determines how the size of the output cube is determined. The choices are MATCH, COMPUTE, and USER. The MATCH option (default) matches the output cube size to the size of the cube provided in the CUBE parameter. The COMPUTE option calculates the output cube size from the Control Network file. The USER parameter allows the user to set the output cube size by entering sample and line values in the ONS and ONL parameters.

Type

string

Default

MATCH

Option List:

Option

Brief

Description

MATCH

Match size of cube

This option will match the output cube to the size of the cube provided in the CUBE parameter.

Exclusions

COMPUTE

Compute size using Control Points

Computes the size of the output file using the Control Network file. This is done by solving for output positions given input positions, then walk the edge of the input file to find the maximum output line and sample.

Exclusions

ONL
ONS
CUBE

USER

User specific output cube size

The output cube size as provided by the ONS and ONL parameters.

Exclusions

CUBE

Inclusions

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Warp parameters: CUBE

Description

The output cube will have the same dimensions as the cube entered here.

Type	cube
File Mode	input
Filter	*.cub

Close Window

Warp parameters: ONL

Description

Requested number of lines for the output cube.

Type	integer
Minimum	1 (inclusive)

Close Window

Warp parameters: ONS

Description

Requested number of samples for the output cube.

Type	integer
Minimum	1 (inclusive)

Close Window

Interpolation: INTERP

Description

This is the type of interpolation to be performed on the input.

Type

string

Default

CUBICCONVOLUTION

Option List:

Option	Brief	Description
NEARESTNEIGHBOR	Nearest Neighbor	Each output pixel will be set to that of the pixel nearest the calculated input pixel.
BILINEAR	Bi-Linear interpolation	Each output pixel value will be set as calculated by a bi-linear pixel value interpolation of an 2x2 pixel array about the calculated input pixel position.
CUBICCONVOLUTION	Cubic Convolution interpolation	Each output pixel value will be set as calculated by a cubic convolution pixel value interpolation of an 4x4 pixel array about the calculated input pixel position.

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Example 1

Warp Example 1

Description

Warp Example 1

Command Line

warp warp from=warp_from.cub to=warp_example1.cub cnet=warp_example1.net osize=user onl=1000 ons=1000

This warp command will warp the from cube (warp_from.cub) which is a 100Sx1000L image, to a 1000Sx1000L image and match the points from the Control Points in warp_example1.net. See the Control Network input file for more details.

Input Image

Input image

Input image for warp

Parameter Name: FROM

This is the input image for the warp examples.

Data File

Links open in a new window.

Control Network input file.	This is the required input for the CNET parameter. In each control point there are two measures. Measure 1 is the point on the from cube you would like to map to measure 2.

Output Image

Output image showing results of the warp application.

Output image for warp

Parameter Name: TO

This is the output image for this example of warp. The Control Network file link below contains the points required to create this kind of a warp output.

Example 2

Warp Example 2

Description

Warp Example 2

Command Line

warp warp from=warp_from.cub to=warp_example2.cub cnetl=warp_example2.net osize=user onl=1000 ons=1000

Input Image

Input image

Input image for warp

Parameter Name: FROM

This is the input image for the warp examples.

Data File

Links open in a new window.

Control Network input file.	This is the required input for the CNET parameter. In each control point there are two measures. Measure 1 is the point on the from cube you would like to map to measure 2.

Output Image

Output image showing results of the warp application.

Output image for warp

Parameter Name: TO

This is the output image for this example of warp. The Control Network file link below contains the points required to create this kind of a warp output.

Example 3

Warp Grid Example 3

Description

This example shows the effect warm has on a grid. A 1000x1000 image with grid lines every 50 pixels was created. The control net file has 4 points where the upper right and lower left corners were held. The upper left and lower right points were move to 100,1 and 800,800, respectively.

Command Line

warp warp from=grid_raw.cub to=grid_warp_weight.cub cnet=warp_points.net osize=user onl=1000 ons=1000 interp=bilinear

This warp command will warp the from cube (grid_raw.cub) which is a 1000Sx1000L image, to a 1000Sx1000L image and match the points from the Control Points in warp_points.net. See the Control Network input file for more details.

Input Image

Input image

Input image for warp

Parameter Name: FROM

This input file is a 1000x1000 size image with grid lines at 50x50 increments.

Data File

Links open in a new window.

Control Network input file.	This is the require input for the CNET parameter. In each control point there are two measures. Measure 1 is the point on the from cube you would like to map to measure 2.

Output Image

Output image showing results of the warp application.

Output image for warp

Parameter Name: TO

This is the output image for this example of warp. The Control Network file link below contains the points required to create this kind of a warp output.

Quick Links

Documentation Versions

warp

Description

Categories

Related Applications to Previous Versions of ISIS

History

Parameter Groups

Files

Warp parameters

Interpolation

Files: FROM

Description

Files: TO

Description

Files: CNET

Description

Warp parameters: DEGREE

Description

Warp parameters: WEIGHTED

Description

Warp parameters: OSIZE

Description

Exclusions

Exclusions

Exclusions

Inclusions

Warp parameters: CUBE

Description

Warp parameters: ONL

Description

Warp parameters: ONS

Description

Interpolation: INTERP

Description

Example 1

Description

Command Line

Input Image

Data File

Output Image

Example 2

Description

Command Line

Input Image

Data File

Output Image

Example 3

Description

Command Line

Input Image

Data File

Output Image