25QString QgsRescaleRasterAlgorithm::name()
const
27 return QStringLiteral(
"rescaleraster" );
30QString QgsRescaleRasterAlgorithm::displayName()
const
32 return QObject::tr(
"Rescale raster" );
35QStringList QgsRescaleRasterAlgorithm::tags()
const
37 return QObject::tr(
"raster,rescale,minimum,maximum,range" ).split(
',' );
40QString QgsRescaleRasterAlgorithm::group()
const
42 return QObject::tr(
"Raster analysis" );
45QString QgsRescaleRasterAlgorithm::groupId()
const
47 return QStringLiteral(
"rasteranalysis" );
50QString QgsRescaleRasterAlgorithm::shortHelpString()
const
52 return QObject::tr(
"Rescales raster layer to a new value range, while preserving the shape "
53 "(distribution) of the raster's histogram (pixel values). Input values "
54 "are mapped using a linear interpolation from the source raster's minimum "
55 "and maximum pixel values to the destination minimum and maximum pixel range.\n\n"
56 "By default the algorithm preserves the original NoData value, but there is "
57 "an option to override it." );
60QgsRescaleRasterAlgorithm *QgsRescaleRasterAlgorithm::createInstance()
const
62 return new QgsRescaleRasterAlgorithm();
65void QgsRescaleRasterAlgorithm::initAlgorithm(
const QVariantMap & )
68 addParameter(
new QgsProcessingParameterBand( QStringLiteral(
"BAND" ), QObject::tr(
"Band number" ), 1, QStringLiteral(
"INPUT" ) ) );
73 std::unique_ptr< QgsProcessingParameterString > createOptsParam = std::make_unique< QgsProcessingParameterString >( QStringLiteral(
"CREATE_OPTIONS" ), QObject::tr(
"Creation options" ), QVariant(),
false,
true );
74 createOptsParam->setMetadata( QVariantMap( {{QStringLiteral(
"widget_wrapper" ), QVariantMap( {{QStringLiteral(
"widget_type" ), QStringLiteral(
"rasteroptions" ) }} ) }} ) );
76 addParameter( createOptsParam.release() );
85 QgsRasterLayer *layer = parameterAsRasterLayer( parameters, QStringLiteral(
"INPUT" ), context );
89 mBand = parameterAsInt( parameters, QStringLiteral(
"BAND" ), context );
90 if ( mBand < 1 || mBand > layer->
bandCount() )
91 throw QgsProcessingException( QObject::tr(
"Invalid band number for BAND (%1): Valid values for input raster are 1 to %2" )
95 mMinimum = parameterAsDouble( parameters, QStringLiteral(
"MINIMUM" ), context );
96 mMaximum = parameterAsDouble( parameters, QStringLiteral(
"MAXIMUM" ), context );
101 mLayerWidth = layer->
width();
102 mLayerHeight = layer->
height();
103 mExtent = layer->
extent();
104 if ( parameters.value( QStringLiteral(
"NODATA" ) ).isValid() )
106 mNoData = parameterAsDouble( parameters, QStringLiteral(
"NODATA" ), context );
113 if ( std::isfinite( mNoData ) )
116 if ( mNoData < std::numeric_limits<float>::lowest() )
117 mNoData = std::numeric_limits<float>::lowest();
118 else if ( mNoData > std::numeric_limits<float>::max() )
119 mNoData = std::numeric_limits<float>::max();
122 mXSize = mInterface->xSize();
123 mYSize = mInterface->ySize();
130 feedback->
pushInfo( QObject::tr(
"Calculating raster minimum and maximum values…" ) );
133 feedback->
pushInfo( QObject::tr(
"Rescaling values…" ) );
134 const QString createOptions = parameterAsString( parameters, QStringLiteral(
"CREATE_OPTIONS" ), context ).trimmed();
135 const QString outputFile = parameterAsOutputLayer( parameters, QStringLiteral(
"OUTPUT" ), context );
136 const QFileInfo fi( outputFile );
138 std::unique_ptr< QgsRasterFileWriter > writer = std::make_unique< QgsRasterFileWriter >( outputFile );
139 writer->setOutputProviderKey( QStringLiteral(
"gdal" ) );
140 if ( !createOptions.isEmpty() )
142 writer->setCreateOptions( createOptions.split(
'|' ) );
145 writer->setOutputFormat( outputFormat );
146 std::unique_ptr<QgsRasterDataProvider > provider( writer->createOneBandRaster(
Qgis::DataType::Float32, mXSize, mYSize, mExtent, mCrs ) );
149 if ( !provider->isValid() )
158 const int numBlocksX =
static_cast< int >( std::ceil( 1.0 * mLayerWidth / blockWidth ) );
159 const int numBlocksY =
static_cast< int >( std::ceil( 1.0 * mLayerHeight / blockHeight ) );
160 const int numBlocks = numBlocksX * numBlocksY;
163 iter.startRasterRead( mBand, mLayerWidth, mLayerHeight, mExtent );
168 std::unique_ptr< QgsRasterBlock > inputBlock;
169 while ( iter.readNextRasterPart( mBand, iterCols, iterRows, inputBlock, iterLeft, iterTop ) )
171 std::unique_ptr< QgsRasterBlock > outputBlock(
new QgsRasterBlock( destProvider->
dataType( 1 ), iterCols, iterRows ) );
172 feedback->
setProgress( 100 * ( ( iterTop / blockHeight * numBlocksX ) + iterLeft / blockWidth ) / numBlocks );
174 for (
int row = 0; row < iterRows; row++ )
179 for (
int col = 0; col < iterCols; col++ )
181 bool isNoData =
false;
182 const double val = inputBlock->valueAndNoData( row, col, isNoData );
185 outputBlock->setValue( row, col, mNoData );
190 outputBlock->setValue( row, col, newValue );
194 destProvider->
writeBlock( outputBlock.get(), mBand, iterLeft, iterTop );
199 outputs.insert( QStringLiteral(
"OUTPUT" ), outputFile );
@ Float32
Thirty two bit floating point (float)
@ Advanced
Parameter is an advanced parameter which should be hidden from users by default.
@ Double
Double/float values.
bool isCanceled() const
Tells whether the operation has been canceled already.
void setProgress(double progress)
Sets the current progress for the feedback object.
virtual QgsRectangle extent() const
Returns the extent of the layer.
QgsCoordinateReferenceSystem crs
Contains information about the context in which a processing algorithm is executed.
Custom exception class for processing related exceptions.
Base class for providing feedback from a processing algorithm.
virtual void pushInfo(const QString &info)
Pushes a general informational message from the algorithm.
A raster band parameter for Processing algorithms.
A numeric parameter for processing algorithms.
A raster layer destination parameter, for specifying the destination path for a raster layer created ...
A raster layer parameter for processing algorithms.
The RasterBandStats struct is a container for statistics about a single raster band.
double minimumValue
The minimum cell value in the raster band.
double maximumValue
The maximum cell value in the raster band.
Base class for raster data providers.
QgsRasterDataProvider * clone() const override=0
Clone itself, create deep copy.
virtual bool setNoDataValue(int bandNo, double noDataValue)
Set no data value on created dataset.
virtual double sourceNoDataValue(int bandNo) const
Value representing no data value.
bool writeBlock(QgsRasterBlock *block, int band, int xOffset=0, int yOffset=0)
Writes pixel data from a raster block into the provider data source.
Qgis::DataType dataType(int bandNo) const override=0
Returns data type for the band specified by number.
virtual bool setEditable(bool enabled)
Turns on/off editing mode of the provider.
static QString driverForExtension(const QString &extension)
Returns the GDAL driver name for a specified file extension.
Iterator for sequentially processing raster cells.
static const int DEFAULT_MAXIMUM_TILE_WIDTH
Default maximum tile width.
static const int DEFAULT_MAXIMUM_TILE_HEIGHT
Default maximum tile height.
Represents a raster layer.
int height() const
Returns the height of the (unclipped) raster.
int bandCount() const
Returns the number of bands in this layer.
QgsRasterDataProvider * dataProvider() override
Returns the source data provider.
int width() const
Returns the width of the (unclipped) raster.
A rectangle specified with double values.