SFSTextureExtraction - SFS Texture Extraction¶

Computes Structural Feature Set textures on every pixel of the input image selected channel

Detailed description¶

Structural Feature Set [1] are based on the histograms of the pixels in multiple directions of the image. The SFSTextureExtraction application computes the 6 following features: SFS’Length, SFS’Width, SFS’PSI, SFS’W-Mean, SFS’Ratio and SFS’SD (Standard Deviation). The texture indices are computed from the neighborhood of each pixel. It is possible to change the length of the calculation line (spatial threshold), as well as the maximum difference between a pixel of the line and the pixel at the center of the neighborhood (spectral threshold) [2].

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 SFSTextureExtraction .

[1]	Table: Parameters table for SFS Texture Extraction.

Parameter Key	Parameter Name	Parameter Type
in	Input Image	Input image
channel	Selected Channel	Int
ram	Available RAM (Mb)	Int
parameters	Texture feature parameters	Group
parameters.spethre	Spectral Threshold	Float
parameters.spathre	Spatial Threshold	Int
parameters.nbdir	Number of Direction	Int
parameters.alpha	Alpha	Float
parameters.maxcons	Ratio Maximum Consideration Number	Int
out	Feature Output Image	Output image
inxml	Load otb application from xml file	XML input parameters file
outxml	Save otb application to xml file	XML output parameters file

Input Image: The input image to compute the features on.

Selected Channel: The selected channel index.

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

[Texture feature parameters]: This group of parameters allows one to define SFS texture parameters. The available texture features are SFS’Length, SFS’Width, SFS’PSI, SFS’W-Mean, SFS’Ratio and SFS’SD. They are provided in this exact order in the output image.

Spectral Threshold: Spectral Threshold.
Spatial Threshold: Spatial Threshold.
Number of Direction: Number of Direction.
Alpha: Alpha.
Ratio Maximum Consideration Number: Ratio Maximum Consideration Number.

Feature Output Image: Output image containing the SFS texture features.

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_SFSTextureExtraction -in qb_RoadExtract.tif -channel 1 -parameters.spethre 50.0 -parameters.spathre 100 -out SFSTextures.tif

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 SFSTextureExtraction application
SFSTextureExtraction = otbApplication.Registry.CreateApplication("SFSTextureExtraction")

# The following lines set all the application parameters:
SFSTextureExtraction.SetParameterString("in", "qb_RoadExtract.tif")

SFSTextureExtraction.SetParameterInt("channel", 1)

SFSTextureExtraction.SetParameterFloat("parameters.spethre", 50.0)

SFSTextureExtraction.SetParameterInt("parameters.spathre", 100)

SFSTextureExtraction.SetParameterString("out", "SFSTextures.tif")

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

Limitations¶

None

Authors¶

This application has been written by OTB-Team.