warp

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.

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

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

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

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)

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

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 ONL ONS 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 ONL ONS

Description

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

Type	filename
File Mode	input
Filter	*.cub

Description

Requested number of lines for the output cube.

Type	integer
Minimum	1 (inclusive)

Description

Requested number of samples for the output cube.

Type	integer
Minimum	1 (inclusive)

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.

Warp Example 1

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

Input image

Input image for warp Parameter Name: FROM This is the input image for the warp examples.

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 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.

Warp Example 2

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

Input image

Input image for warp Parameter Name: FROM This is the input image for the warp examples.

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 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.

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.

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

Input image

Input image for warp Parameter Name: FROM This input file is a 1000x1000 size image with grid lines at 50x50 increments.

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 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.