Base class for raster analysis methods that work with a 3x3 cell filter and calculate the value of each cell based on the cell value and the eight neighbour cells. More...

#include <qgsninecellfilter.h>

Inheritance diagram for QgsNineCellFilter:

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Public Member Functions
	QgsNineCellFilter (const QString &inputFile, const QString &outputFile, const QString &outputFormat)
	Constructor that takes input file, output file and output format (GDAL string)

virtual	~QgsNineCellFilter ()=default

double	cellSizeX () const

double	cellSizeY () const

double	inputNodataValue () const

double	outputNodataValue () const

virtual float	processNineCellWindow (float x11, float x21, float x31, float x12, float x22, float x32, float x13, float x23, float *x33)=0
	Calculates output value from nine input values.

int	processRaster (QgsFeedback *feedback=nullptr)
	Starts the calculation, reads from mInputFile and stores the result in mOutputFile.

void	setCellSizeX (double size)

void	setCellSizeY (double size)

void	setInputNodataValue (double value)

void	setOutputNodataValue (double value)

void	setZFactor (double factor)

double	zFactor () const

Protected Attributes
double	mCellSizeX = -1.0

double	mCellSizeY = -1.0

QString	mInputFile

float	mInputNodataValue = -1.0
	The nodata value of the input layer.

QString	mOutputFile

QString	mOutputFormat

float	mOutputNodataValue = -1.0
	The nodata value of the output layer.

double	mZFactor = 1.0
	Scale factor for z-value if x-/y- units are different to z-units (111120 for degree->meters and 370400 for degree->feet)

Detailed Description

Base class for raster analysis methods that work with a 3x3 cell filter and calculate the value of each cell based on the cell value and the eight neighbour cells.

Common examples are slope and aspect calculation in DEMs. Subclasses only implement the method that calculates the new value from the nine values. Everything else (reading file, writing file) is done by this subclass

Definition at line 37 of file qgsninecellfilter.h.

Constructor & Destructor Documentation

◆ QgsNineCellFilter()

QgsNineCellFilter::QgsNineCellFilter	(	const QString &	inputFile,
		const QString &	outputFile,
		const QString &	outputFormat
	)

Constructor that takes input file, output file and output format (GDAL string)

Definition at line 38 of file qgsninecellfilter.cpp.

◆ ~QgsNineCellFilter()

virtual QgsNineCellFilter::~QgsNineCellFilter ( )

virtualdefault

Member Function Documentation

◆ cellSizeX()

double QgsNineCellFilter::cellSizeX ( ) const

inline

Definition at line 51 of file qgsninecellfilter.h.

◆ cellSizeY()

double QgsNineCellFilter::cellSizeY ( ) const

inline

Definition at line 53 of file qgsninecellfilter.h.

◆ inputNodataValue()

double QgsNineCellFilter::inputNodataValue ( ) const

inline

Definition at line 59 of file qgsninecellfilter.h.

◆ outputNodataValue()

double QgsNineCellFilter::outputNodataValue ( ) const

inline

Definition at line 61 of file qgsninecellfilter.h.

◆ processNineCellWindow()

virtual float QgsNineCellFilter::processNineCellWindow	(	float *	x11,
		float *	x21,
		float *	x31,
		float *	x12,
		float *	x22,
		float *	x32,
		float *	x13,
		float *	x23,
		float *	x33
	)

pure virtual

Calculates output value from nine input values.

The input values and the output value can be equal to the nodata value if not present or outside of the border. Must be implemented by subclasses.

First index of the input cell is the row, second index is the column

Parameters

x11	surrounding cell top left
x21	surrounding cell central left
x31	surrounding cell bottom left
x12	surrounding cell top central
x22	the central cell for which the value will be calculated
x32	surrounding cell bottom central
x13	surrounding cell top right
x23	surrounding cell central right
x33	surrounding cell bottom right

Returns: the calculated cell value for the central cell x22

Implemented in QgsAspectFilter, QgsHillshadeFilter, QgsRuggednessFilter, QgsSlopeFilter, QgsTotalCurvatureFilter, and QgsDerivativeFilter.

◆ processRaster()

int QgsNineCellFilter::processRaster ( QgsFeedback * feedback = nullptr )

Starts the calculation, reads from mInputFile and stores the result in mOutputFile.

Parameters

feedback feedback object that receives update and that is checked for cancellation.

Returns: 0 in case of success

Definition at line 47 of file qgsninecellfilter.cpp.

◆ setCellSizeX()

void QgsNineCellFilter::setCellSizeX ( double size )

inline

Definition at line 52 of file qgsninecellfilter.h.

◆ setCellSizeY()

void QgsNineCellFilter::setCellSizeY ( double size )

inline

Definition at line 54 of file qgsninecellfilter.h.

◆ setInputNodataValue()

void QgsNineCellFilter::setInputNodataValue ( double value )

inline

Definition at line 60 of file qgsninecellfilter.h.

◆ setOutputNodataValue()

void QgsNineCellFilter::setOutputNodataValue ( double value )

inline

Definition at line 62 of file qgsninecellfilter.h.

◆ setZFactor()

void QgsNineCellFilter::setZFactor ( double factor )

inline

Definition at line 57 of file qgsninecellfilter.h.

◆ zFactor()

double QgsNineCellFilter::zFactor ( ) const

inline

Definition at line 56 of file qgsninecellfilter.h.

Member Data Documentation

◆ mCellSizeX

double QgsNineCellFilter::mCellSizeX = -1.0

protected

Definition at line 145 of file qgsninecellfilter.h.

◆ mCellSizeY

double QgsNineCellFilter::mCellSizeY = -1.0

protected

Definition at line 146 of file qgsninecellfilter.h.

◆ mInputFile

QString QgsNineCellFilter::mInputFile

protected

Definition at line 141 of file qgsninecellfilter.h.

◆ mInputNodataValue

float QgsNineCellFilter::mInputNodataValue = -1.0

protected

The nodata value of the input layer.

Definition at line 148 of file qgsninecellfilter.h.

◆ mOutputFile

QString QgsNineCellFilter::mOutputFile

protected

Definition at line 142 of file qgsninecellfilter.h.

◆ mOutputFormat

QString QgsNineCellFilter::mOutputFormat

protected

Definition at line 143 of file qgsninecellfilter.h.

◆ mOutputNodataValue

float QgsNineCellFilter::mOutputNodataValue = -1.0

protected

The nodata value of the output layer.

Definition at line 150 of file qgsninecellfilter.h.

◆ mZFactor

double QgsNineCellFilter::mZFactor = 1.0

protected

Scale factor for z-value if x-/y- units are different to z-units (111120 for degree->meters and 370400 for degree->feet)

Definition at line 152 of file qgsninecellfilter.h.

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

/build/qgis-3.41.0+git20241122+3440c17df1d+99sid/src/analysis/raster/qgsninecellfilter.h
/build/qgis-3.41.0+git20241122+3440c17df1d+99sid/src/analysis/raster/qgsninecellfilter.cpp

Public Member Functions

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

◆ QgsNineCellFilter()

◆ ~QgsNineCellFilter()

Member Function Documentation

◆ cellSizeX()

◆ cellSizeY()

◆ inputNodataValue()

◆ outputNodataValue()

◆ processNineCellWindow()

◆ processRaster()

◆ setCellSizeX()

◆ setCellSizeY()

◆ setInputNodataValue()

◆ setOutputNodataValue()

◆ setZFactor()

◆ zFactor()

Member Data Documentation

◆ mCellSizeX

◆ mCellSizeY

◆ mInputFile

◆ mInputNodataValue

◆ mOutputFile

◆ mOutputFormat

◆ mOutputNodataValue

◆ mZFactor