GridBasedImageResampling - Grid Based Image Resampling¶

Resamples an image according to a resampling grid

Detailed description¶

This application allows performing image resampling from an input resampling grid.

Parameters¶

This section describes in details the parameters available for this application. Table [1] presents a summary of these parameters and the parameters keys to be used in command-line and programming languages. Application key is GridBasedImageResampling .

[1]	Table: Parameters table for Grid Based Image Resampling.

Parameter Key	Parameter Name	Parameter Type
io	Input and output data	Group
io.in	Input image	Input image
io.out	Output Image	Output image
grid	Resampling grid parameters	Group
grid.in	Input resampling grid	Input image
grid.type	Grid Type	Choices
grid.type def	Displacement grid: $G(x_out,y_out) = (x_in-x_out, y_in-y_out)$	Choice
grid.type loc	Localisation grid: $G(x_out,y_out) = (x_in, y_in)$	Choice
out	Output Image parameters	Group
out.ulx	Upper Left X	Float
out.uly	Upper Left Y	Float
out.sizex	Size X	Int
out.sizey	Size Y	Int
out.spacingx	Pixel Size X	Float
out.spacingy	Pixel Size Y	Float
out.default	Default value	Float
interpolator	Interpolation	Choices
interpolator nn	Nearest Neighbor interpolation	Choice
interpolator linear	Linear interpolation	Choice
interpolator bco	Bicubic interpolation	Choice
interpolator.bco.radius	Radius for bicubic interpolation	Int
ram	Available RAM (Mb)	Int
inxml	Load otb application from xml file	XML input parameters file
outxml	Save otb application to xml file	XML output parameters file

[Input and output data]: This group of parameters allows setting the input and output images.

Input image: The input image to resample.
Output Image: The resampled output image.

[Resampling grid parameters]

Input resampling grid: The resampling grid.
Grid Type: allows one to choose between two grid types. Available choices are:

Displacement grid: $G(x_out,y_out) = (x_in-x_out, y_in-y_out)$: A deformation grid contains at each grid position the offset to apply to this position in order to get to the corresponding point in the input image to resample.

Localisation grid: $G(x_out,y_out) = (x_in, y_in)$: A localisation grid contains at each grid position the corresponding position in the input image to resample.

[Output Image parameters]: Parameters of the output image.

Upper Left X: X Coordinate of the upper-left pixel of the output resampled image.
Upper Left Y: Y Coordinate of the upper-left pixel of the output resampled image.
Size X: Size of the output resampled image along X (in pixels).
Size Y: Size of the output resampled image along Y (in pixels).
Pixel Size X: Size of each pixel along X axis.
Pixel Size Y: Size of each pixel along Y axis.
Default value: The default value to give to pixel that falls outside of the input image.

Interpolation: This group of parameters allows one to define how the input image will be interpolated during resampling. Available choices are:

Nearest Neighbor interpolation: Nearest neighbor interpolation leads to poor image quality, but it is very fast.
Linear interpolation: Linear interpolation leads to average image quality but is quite fast.
Bicubic interpolation

Radius for bicubic interpolation: This parameter allows controlling the size of the bicubic interpolation filter. If the target pixel size is higher than the input pixel size, increasing this parameter will reduce aliasing artifacts.

Available RAM (Mb): Available memory for processing (in MB).

Load otb application from xml file: Load otb application from xml file.

Save otb application to xml file: Save otb application to xml file.

Example¶

To run this example in command-line, use the following:

otbcli_GridBasedImageResampling -io.in ROI_IKO_PAN_LesHalles_sub.tif -io.out ROI_IKO_PAN_LesHalles_sub_resampled.tif uint8 -grid.in ROI_IKO_PAN_LesHalles_sub_deformation_field.tif -out.sizex 256 -out.sizey 256 -grid.type def

To run this example from Python, use the following code snippet:

#!/usr/bin/python

# Import the otb applications package
import otbApplication

# The following line creates an instance of the GridBasedImageResampling application
GridBasedImageResampling = otbApplication.Registry.CreateApplication("GridBasedImageResampling")

# The following lines set all the application parameters:
GridBasedImageResampling.SetParameterString("io.in", "ROI_IKO_PAN_LesHalles_sub.tif")

GridBasedImageResampling.SetParameterString("io.out", "ROI_IKO_PAN_LesHalles_sub_resampled.tif")
GridBasedImageResampling.SetParameterOutputImagePixelType("io.out", 1)

GridBasedImageResampling.SetParameterString("grid.in", "ROI_IKO_PAN_LesHalles_sub_deformation_field.tif")

GridBasedImageResampling.SetParameterInt("out.sizex", 256)

GridBasedImageResampling.SetParameterInt("out.sizey", 256)

GridBasedImageResampling.SetParameterString("grid.type","def")

# The following line execute the application
GridBasedImageResampling.ExecuteAndWriteOutput()

Limitations¶

None

Authors¶

This application has been written by OTB-Team.