QGIS API Documentation
3.0.2-Girona (307d082)
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Manipulates raster pixel values so that they enhanceContrast or clip into a specified numerical range according to the specified ContrastEnhancementAlgorithm. More...
#include <qgscontrastenhancement.h>
Public Types | |
enum | ContrastEnhancementAlgorithm { NoEnhancement, StretchToMinimumMaximum, StretchAndClipToMinimumMaximum, ClipToMinimumMaximum, UserDefinedEnhancement } |
This enumerator describes the types of contrast enhancement algorithms that can be used. More... | |
Public Member Functions | |
QgsContrastEnhancement (Qgis::DataType datatype=Qgis::Byte) | |
QgsContrastEnhancement (const QgsContrastEnhancement &ce) | |
~QgsContrastEnhancement () | |
ContrastEnhancementAlgorithm | contrastEnhancementAlgorithm () const |
int | enhanceContrast (double) |
Apply the contrast enhancement to a value. Return values are 0 - 254, -1 means the pixel was clipped and should not be displayed. More... | |
bool | isValueInDisplayableRange (double) |
Return true if pixel is in stretable range, false if pixel is outside of range (i.e., clipped) More... | |
double | maximumValue () const |
Return the maximum value for the contrast enhancement range. More... | |
double | minimumValue () const |
Return the minimum value for the contrast enhancement range. More... | |
const QgsContrastEnhancement & | operator= (const QgsContrastEnhancement &)=delete |
void | readXml (const QDomElement &elem) |
void | setContrastEnhancementAlgorithm (ContrastEnhancementAlgorithm, bool generateTable=true) |
Set the contrast enhancement algorithm. More... | |
void | setContrastEnhancementFunction (QgsContrastEnhancementFunction *) |
A public method that allows the user to set their own custom contrast enhancement function. More... | |
void | setMaximumValue (double, bool generateTable=true) |
Set the maximum value for the contrast enhancement range. More... | |
void | setMinimumValue (double, bool generateTable=true) |
Return the minimum value for the contrast enhancement range. More... | |
void | writeXml (QDomDocument &doc, QDomElement &parentElem) const |
Static Public Member Functions | |
static ContrastEnhancementAlgorithm | contrastEnhancementAlgorithmFromString (const QString &contrastEnhancementString) |
Deserialize ContrastEnhancementAlgorithm. More... | |
static QString | contrastEnhancementAlgorithmString (ContrastEnhancementAlgorithm algorithm) |
Return a string to serialize ContrastEnhancementAlgorithm. More... | |
static double | maximumValuePossible (Qgis::DataType) |
Helper function that returns the maximum possible value for a GDAL data type. More... | |
static double | minimumValuePossible (Qgis::DataType) |
Helper function that returns the minimum possible value for a GDAL data type. More... | |
Manipulates raster pixel values so that they enhanceContrast or clip into a specified numerical range according to the specified ContrastEnhancementAlgorithm.
Definition at line 42 of file qgscontrastenhancement.h.
This enumerator describes the types of contrast enhancement algorithms that can be used.
Enumerator | |
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NoEnhancement | |
StretchToMinimumMaximum | |
StretchAndClipToMinimumMaximum | |
ClipToMinimumMaximum | |
UserDefinedEnhancement |
Definition at line 48 of file qgscontrastenhancement.h.
QgsContrastEnhancement::QgsContrastEnhancement | ( | Qgis::DataType | datatype = Qgis::Byte | ) |
Definition at line 32 of file qgscontrastenhancement.cpp.
QgsContrastEnhancement::QgsContrastEnhancement | ( | const QgsContrastEnhancement & | ce | ) |
Definition at line 51 of file qgscontrastenhancement.cpp.
QgsContrastEnhancement::~QgsContrastEnhancement | ( | ) |
Definition at line 70 of file qgscontrastenhancement.cpp.
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inline |
Definition at line 91 of file qgscontrastenhancement.h.
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Deserialize ContrastEnhancementAlgorithm.
Definition at line 440 of file qgscontrastenhancement.cpp.
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Return a string to serialize ContrastEnhancementAlgorithm.
Definition at line 422 of file qgscontrastenhancement.cpp.
int QgsContrastEnhancement::enhanceContrast | ( | double | value | ) |
Apply the contrast enhancement to a value. Return values are 0 - 254, -1 means the pixel was clipped and should not be displayed.
Public function to generate the enhanced for enhanceContrasted value for a given input.
value | The pixel value to enhance |
Definition at line 169 of file qgscontrastenhancement.cpp.
bool QgsContrastEnhancement::isValueInDisplayableRange | ( | double | value | ) |
Return true if pixel is in stretable range, false if pixel is outside of range (i.e., clipped)
Determine if a pixel is within in the displayable range.
value | The pixel value to examine |
Definition at line 227 of file qgscontrastenhancement.cpp.
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inline |
Return the maximum value for the contrast enhancement range.
Definition at line 86 of file qgscontrastenhancement.h.
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Helper function that returns the maximum possible value for a GDAL data type.
Simple function to compute the maximum possible value for a data types.
Definition at line 83 of file qgscontrastenhancement.cpp.
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inline |
Return the minimum value for the contrast enhancement range.
Definition at line 89 of file qgscontrastenhancement.h.
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static |
Helper function that returns the minimum possible value for a GDAL data type.
Simple function to compute the minimum possible value for a data type.
Definition at line 122 of file qgscontrastenhancement.cpp.
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delete |
void QgsContrastEnhancement::readXml | ( | const QDomElement & | elem | ) |
Definition at line 375 of file qgscontrastenhancement.cpp.
void QgsContrastEnhancement::setContrastEnhancementAlgorithm | ( | ContrastEnhancementAlgorithm | algorithm, |
bool | generateTable = true |
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) |
Set the contrast enhancement algorithm.
The second parameter is optional and is for performance improvements. If you know you are immediately going to set the Minimum or Maximum value, you can elect to not generate the lookup tale. By default it will be generated.
algorithm | The new contrast enhancement algorithm |
generateTable | Flag to override automatic look up table generation |
Definition at line 243 of file qgscontrastenhancement.cpp.
void QgsContrastEnhancement::setContrastEnhancementFunction | ( | QgsContrastEnhancementFunction * | function | ) |
A public method that allows the user to set their own custom contrast enhancement function.
A public function that allows the user to set their own custom contrast enhancement function.
function | The new contrast enhancement function |
Definition at line 278 of file qgscontrastenhancement.cpp.
void QgsContrastEnhancement::setMaximumValue | ( | double | value, |
bool | generateTable = true |
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) |
Set the maximum value for the contrast enhancement range.
Set the maximum value for the contrast enhancement.
The second parameter is option an is for performance improvements. If you know you are immediately going to set the Minimum value or the contrast enhancement algorithm, you can elect to not generate the lookup tale. By default it will be generated.
value | The new maximum value for the band |
generateTable | Flag to override automatic look up table generation |
Definition at line 296 of file qgscontrastenhancement.cpp.
void QgsContrastEnhancement::setMinimumValue | ( | double | value, |
bool | generateTable = true |
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) |
Return the minimum value for the contrast enhancement range.
Set the maximum value for the contrast enhancement.
The second parameter is option an is for performance improvements. If you know you are immediately going to set the Maximum value or the contrast enhancement algorithm, you can elect to not generate the lookup tale. By default it will be generated.
value | The new minimum value for the band |
generateTable | Flag to override automatic look up table generation |
Definition at line 328 of file qgscontrastenhancement.cpp.
void QgsContrastEnhancement::writeXml | ( | QDomDocument & | doc, |
QDomElement & | parentElem | ||
) | const |
Definition at line 354 of file qgscontrastenhancement.cpp.