NDVI (normalized difference vegetation index) feature extraction class. More...

#include <NDVI.h>

Inheritance diagram for DirectGraphicalModels::fex::CNDVI:

Collaboration diagram for DirectGraphicalModels::fex::CNDVI:

Public Member Functions
	CNDVI (const Mat &img)
	Constructor. More...

virtual	~CNDVI (void)

virtual Mat	get (void) const
	Extracts and returns the required feature. More...

Public Member Functions inherited from DirectGraphicalModels::fex::ILocalFeatureExtractor
	ILocalFeatureExtractor (const Mat &img)
	Constructor. More...

virtual	~ILocalFeatureExtractor (void)

Public Member Functions inherited from DirectGraphicalModels::fex::IFeatureExtractor
	IFeatureExtractor (const Mat &img)
	Constructor. More...

virtual	~IFeatureExtractor (void)

Static Public Member Functions
static Mat	get (const Mat &img, byte midPoint=127)
	Extracts the NDVI feature. More...

Additional Inherited Members
Protected Attributes inherited from DirectGraphicalModels::fex::IFeatureExtractor
const Mat	m_img
	Container for the image, from which the features are to be extracted. More...

Detailed Description

NDVI (normalized difference vegetation index) feature extraction class.

Author: Sergey G. Kosov, serge.nosp@m.y.ko.nosp@m.sov@p.nosp@m.roje.nosp@m.ct-10.nosp@m..de

Definition at line 14 of file NDVI.h.

Constructor & Destructor Documentation

◆ CNDVI()

DirectGraphicalModels::fex::CNDVI::CNDVI ( const Mat & img )

inline

Constructor.

Parameters

img	Input image of type CV_8UC3.

Definition at line 21 of file NDVI.h.

◆ ~CNDVI()

virtual DirectGraphicalModels::fex::CNDVI::~CNDVI ( void )

inlinevirtual

Definition at line 22 of file NDVI.h.

Member Function Documentation

◆ get() [1/2]

virtual Mat DirectGraphicalModels::fex::CNDVI::get ( void ) const

inlinevirtual

Extracts and returns the required feature.

Returns: The feature image.

Implements DirectGraphicalModels::fex::ILocalFeatureExtractor.

Definition at line 24 of file NDVI.h.

Here is the caller graph for this function:

◆ get() [2/2]

Mat DirectGraphicalModels::fex::CNDVI::get	(	const Mat &	img,
		byte	midPoint = `127`
	)

static

Extracts the NDVI feature.

This function calculates the NDVI from the input image as follows:

\[ NDVI=\frac{NIR-VIS}{NIR+VIS},\]

where \(NIR\) designates the near-infra-red data, and \(VIS\) - visible data. The algorithm assumes that the near-infra-red data is stored in the red image channel and the visible data - in the remaining two channels:

\begin{eqnarray*}NIR&=&img.RED \\ VIS&=&\frac{1}{2}\,img.GREEN+\frac{1}{2}\,img.BLUE.\end{eqnarray*}

As \(NDVI\in[-1; 1]\), this function performs two-linear mapping of the NDVI values to the interval \([0; 255]\), such that:

\begin{eqnarray*}-1&\rightarrow&0 \\ 0&\rightarrow&midPoint \\ 1&\rightarrow&255\end{eqnarray*}

For more details on mapping refer to the two_linear_mapper() function.

Parameters

img	Input image of type CV_8UC3, where near-infra-red data is stored in the red channel.
midPoint	Parameter for the two-linear mapping of the feature (Ref. two_linear_mapper()). Common values are: 0 - cut off the negative NDVI values; 127 - linear mapping; 255 - cut off the positive NDVI values.

Returns: The NDVI feature image of type CV_8UC1.

Definition at line 7 of file NDVI.cpp.

The documentation for this class was generated from the following files:

D:/Projects/DGM/modules/FEX/NDVI.h
D:/Projects/DGM/modules/FEX/NDVI.cpp

Public Member Functions

Static Public Member Functions