GDALColorTable Class Reference

A color table / palette. More...

#include <gdal_priv.h>

Public Member Functions
	GDALColorTable (GDALPaletteInterp=GPI_RGB)
	Construct a new color table. More...
	~GDALColorTable ()
	Destructor. More...
GDALColorTable *	Clone () const
	Make a copy of a color table. More...
int	IsSame (const GDALColorTable *poOtherCT) const
	Returns if the current color table is the same as another one. More...
GDALPaletteInterp	GetPaletteInterpretation () const
	Fetch palette interpretation. More...
int	GetColorEntryCount () const
	Get number of color entries in table. More...
const GDALColorEntry *	GetColorEntry (int) const
	Fetch a color entry from table. More...
int	GetColorEntryAsRGB (int, GDALColorEntry *) const
	Fetch a table entry in RGB format. More...
void	SetColorEntry (int, const GDALColorEntry *)
	Set entry in color table. More...
int	CreateColorRamp (int, const GDALColorEntry *, int, const GDALColorEntry *)
	Create color ramp. More...

Static Public Member Functions
static GDALColorTableH	ToHandle (GDALColorTable *poCT)
	Convert a GDALColorTable* to a GDALRasterBandH. More...
static GDALColorTable *	FromHandle (GDALColorTableH hCT)
	Convert a GDALColorTableH to a GDALColorTable*. More...

Detailed Description

A color table / palette.

Constructor & Destructor Documentation

GDALColorTable()

GDALColorTable::GDALColorTable ( GDALPaletteInterp  eInterpIn = GPI_RGB )

explicit

Construct a new color table.

This constructor is the same as the C GDALCreateColorTable() function.

Parameters

eInterpIn

the interpretation to be applied to GDALColorEntry values.

~GDALColorTable()

GDALColorTable::~GDALColorTable ( )

default

Destructor.

This destructor is the same as the C GDALDestroyColorTable() function.

Member Function Documentation

Clone()

GDALColorTable * GDALColorTable::Clone

(

)

const

Make a copy of a color table.

This method is the same as the C function GDALCloneColorTable().

CreateColorRamp()

int GDALColorTable::CreateColorRamp	(	int	nStartIndex,
		const GDALColorEntry *	psStartColor,
		int	nEndIndex,
		const GDALColorEntry *	psEndColor
	)

Create color ramp.

Automatically creates a color ramp from one color entry to another. It can be called several times to create multiples ramps in the same color table.

This function is the same as the C function GDALCreateColorRamp().

Parameters

nStartIndex	index to start the ramp on the color table [0..255]
psStartColor	a color entry value to start the ramp
nEndIndex	index to end the ramp on the color table [0..255]
psEndColor	a color entry value to end the ramp

Returns

total number of entries, -1 to report error

FromHandle()

static GDALColorTable* GDALColorTable::FromHandle ( GDALColorTableH  hCT )

inlinestatic

Convert a GDALColorTableH to a GDALColorTable*.

Since

GDAL 2.3

GetColorEntry()

const GDALColorEntry * GDALColorTable::GetColorEntry

(

int

i

)

const

Fetch a color entry from table.

This method is the same as the C function GDALGetColorEntry().

Parameters

i	entry offset from zero to GetColorEntryCount()-1.

Returns

pointer to internal color entry, or NULL if index is out of range.

GetColorEntryAsRGB()

int GDALColorTable::GetColorEntryAsRGB	(	int	i,
		GDALColorEntry *	poEntry
	)		const

Fetch a table entry in RGB format.

In theory this method should support translation of color palettes in non-RGB color spaces into RGB on the fly, but currently it only works on RGB color tables.

This method is the same as the C function GDALGetColorEntryAsRGB().

Parameters

i	entry offset from zero to GetColorEntryCount()-1.
poEntry	the existing GDALColorEntry to be overrwritten with the RGB values.

Returns

TRUE on success, or FALSE if the conversion isn't supported.

GetColorEntryCount()

int GDALColorTable::GetColorEntryCount

(

)

const

Get number of color entries in table.

This method is the same as the function GDALGetColorEntryCount().

Returns

the number of color entries.

GetPaletteInterpretation()

GDALPaletteInterp GDALColorTable::GetPaletteInterpretation

(

)

const

Fetch palette interpretation.

The returned value is used to interpret the values in the GDALColorEntry.

This method is the same as the C function GDALGetPaletteInterpretation().

Returns

palette interpretation enumeration value, usually GPI_RGB.

IsSame()

int GDALColorTable::IsSame

(

const GDALColorTable *

poOtherCT

)

const

Returns if the current color table is the same as another one.

Parameters

poOtherCT

other color table to be compared to.

Returns

TRUE if both color tables are identical.

Since

GDAL 2.0

SetColorEntry()

void GDALColorTable::SetColorEntry	(	int	i,
		const GDALColorEntry *	poEntry
	)

Set entry in color table.

Note that the passed in color entry is copied, and no internal reference to it is maintained. Also, the passed in entry must match the color interpretation of the table to which it is being assigned.

The table is grown as needed to hold the supplied offset.

This function is the same as the C function GDALSetColorEntry().

Parameters

i	entry offset from zero to GetColorEntryCount()-1.
poEntry	value to assign to table.

ToHandle()

static GDALColorTableH GDALColorTable::ToHandle ( GDALColorTable *  poCT )

inlinestatic

Convert a GDALColorTable* to a GDALRasterBandH.

Since

GDAL 2.3

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

• gdal_priv.h
• gdalcolortable.cpp