Produces coloured relief rasters from DEM. More...

#include <qgsrelief.h>

Collaboration diagram for QgsRelief:

Classes
struct	ReliefColor

Public Member Functions
	QgsRelief (const QString &inputFile, const QString &outputFile, const QString &outputFormat)
	~QgsRelief ()
int	processRaster (QProgressDialog *p)
	Starts the calculation, reads from mInputFile and stores the result in mOutputFile.
double	zFactor () const
void	setZFactor (double factor)
void	clearReliefColors ()
void	addReliefColorClass (const ReliefColor &color)
const QList< ReliefColor > &	reliefColors () const
void	setReliefColors (const QList< ReliefColor > &c)
QList< ReliefColor >	calculateOptimizedReliefClasses ()
	Calculates class breaks according with the method of Buenzli (2011) using an iterative algorithm for segmented regression.
bool	exportFrequencyDistributionToCsv (const QString &file)
	Write frequency of elevation values to file for manual inspection.

Private Member Functions
bool	processNineCellWindow (float x1, float x2, float x3, float x4, float x5, float x6, float x7, float x8, float x9, unsigned char red, unsigned char green, unsigned char blue)
GDALDatasetH	openInputFile (int &nCellsX, int &nCellsY)
	Opens the input file and returns the dataset handle and the number of pixels in x-/y- direction.
GDALDriverH	openOutputDriver ()
	Opens the output driver and tests if it supports the creation of a new dataset.
GDALDatasetH	openOutputFile (GDALDatasetH inputDataset, GDALDriverH outputDriver)
	Opens the output file and sets the same geotransform and CRS as the input data.
bool	setElevationColor (double elevation, int red, int green, int *blue)
	Set elevation color.
void	setDefaultReliefColors ()
	Sets relief colors.
int	frequencyClassForElevation (double elevation, double minElevation, double elevationClassRange)
	Returns class (0-255) for an elevation value.
void	optimiseClassBreaks (QList< int > &breaks, double *frequencies)
	Do one iteration of class break optimisation (algorithm from Garcia and Rodriguez)
bool	calculateRegression (const QList< QPair< int, double > > &input, double &a, double &b)
	Calculates coefficients a and b.

Private Attributes
QString	mInputFile
QString	mOutputFile
QString	mOutputFormat
double	mCellSizeX
double	mCellSizeY
float	mInputNodataValue
	The nodata value of the input layer.
float	mOutputNodataValue
	The nodata value of the output layer.
double	mZFactor
QgsSlopeFilter *	mSlopeFilter
QgsAspectFilter *	mAspectFilter
QgsHillshadeFilter *	mHillshadeFilter285
QgsHillshadeFilter *	mHillshadeFilter300
QgsHillshadeFilter *	mHillshadeFilter315
QList< ReliefColor >	mReliefColors

Detailed Description

Produces coloured relief rasters from DEM.

Definition at line 33 of file qgsrelief.h.

Constructor & Destructor Documentation

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

Definition at line 36 of file qgsrelief.cpp.

References mAspectFilter, mHillshadeFilter285, mHillshadeFilter300, mHillshadeFilter315, and mSlopeFilter.

QgsRelief::~QgsRelief ( )

Definition at line 49 of file qgsrelief.cpp.

References mAspectFilter, mHillshadeFilter285, mHillshadeFilter300, mHillshadeFilter315, and mSlopeFilter.

Member Function Documentation

void QgsRelief::addReliefColorClass ( const ReliefColor & color )

Definition at line 63 of file qgsrelief.cpp.

References mReliefColors.

Referenced by setDefaultReliefColors().

QList< QgsRelief::ReliefColor > QgsRelief::calculateOptimizedReliefClasses ( )

Calculates class breaks according with the method of Buenzli (2011) using an iterative algorithm for segmented regression.

Returns: true in case of success

Definition at line 562 of file qgsrelief.cpp.

References frequencyClassForElevation(), openInputFile(), and optimiseClassBreaks().

bool QgsRelief::calculateRegression	(	const QList< QPair< int, double > > &	input,
		double &	a,
		double &	b
	)

private

Calculates coefficients a and b.

Parameters

input	data points ( elevation class / frequency )
a	slope
b	y value for x=0

Definition at line 755 of file qgsrelief.cpp.

Referenced by optimiseClassBreaks().

void QgsRelief::clearReliefColors ( )

Definition at line 58 of file qgsrelief.cpp.

References mReliefColors.

Referenced by setDefaultReliefColors().

bool QgsRelief::exportFrequencyDistributionToCsv ( const QString & file )

Write frequency of elevation values to file for manual inspection.

Definition at line 481 of file qgsrelief.cpp.

References frequencyClassForElevation(), and openInputFile().

int QgsRelief::frequencyClassForElevation	(	double	elevation,
		double	minElevation,
		double	elevationClassRange
	)

private

Returns class (0-255) for an elevation value.

Returns: elevation class or -1 in case of error

Definition at line 750 of file qgsrelief.cpp.

Referenced by calculateOptimizedReliefClasses(), and exportFrequencyDistributionToCsv().

GDALDatasetH QgsRelief::openInputFile	(	int &	nCellsX,
		int &	nCellsY
	)

private

Opens the input file and returns the dataset handle and the number of pixels in x-/y- direction.

Definition at line 391 of file qgsrelief.cpp.

References mInputFile, and TO8F.

Referenced by calculateOptimizedReliefClasses(), exportFrequencyDistributionToCsv(), and processRaster().

GDALDriverH QgsRelief::openOutputDriver ( )

private

Opens the output driver and tests if it supports the creation of a new dataset.

Returns: NULL on error and the driver handle on success

Definition at line 409 of file qgsrelief.cpp.

References mOutputFormat.

Referenced by processRaster().

GDALDatasetH QgsRelief::openOutputFile	(	GDALDatasetH	inputDataset,
		GDALDriverH	outputDriver
	)

private

Opens the output file and sets the same geotransform and CRS as the input data.

Returns: the output dataset or NULL in case of error

Definition at line 430 of file qgsrelief.cpp.

References mCellSizeX, mCellSizeY, mOutputFile, and TO8F.

Referenced by processRaster().

void QgsRelief::optimiseClassBreaks	(	QList< int > &	breaks,
		double *	frequencies
	)

private

Do one iteration of class break optimisation (algorithm from Garcia and Rodriguez)

Definition at line 680 of file qgsrelief.cpp.

References calculateRegression(), and qgsDoubleNear().

Referenced by calculateOptimizedReliefClasses().

bool QgsRelief::processNineCellWindow	(	float *	x1,
		float *	x2,
		float *	x3,
		float *	x4,
		float *	x5,
		float *	x6,
		float *	x7,
		float *	x8,
		float *	x9,
		unsigned char *	red,
		unsigned char *	green,
		unsigned char *	blue
	)