QGIS API Documentation 3.38.0-Grenoble (exported)
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qgsalgorithmfillnodata.cpp
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1/***************************************************************************
2 qgsalgorithmfillnodata.cpp
3 ---------------------
4 begin : January 2020
5 copyright : (C) 2020 by Clemens Raffler
6 email : clemens dot raffler at gmail dot com
7 ***************************************************************************/
8
9/***************************************************************************
10 * *
11 * This program is free software; you can redistribute it and/or modify *
12 * it under the terms of the GNU General Public License as published by *
13 * the Free Software Foundation; either version 2 of the License, or *
14 * (at your option) any later version. *
15 * *
16 ***************************************************************************/
17
19#include "qgsrasterfilewriter.h"
20
22
23QString QgsFillNoDataAlgorithm::name() const
24{
25 return QStringLiteral( "fillnodata" );
26}
27
28QString QgsFillNoDataAlgorithm::displayName() const
29{
30 return QObject::tr( "Fill NoData cells" );
31}
32
33QStringList QgsFillNoDataAlgorithm::tags() const
34{
35 return QObject::tr( "data,cells,fill,set" ).split( ',' );
36}
37
38QString QgsFillNoDataAlgorithm::group() const
39{
40 return QObject::tr( "Raster tools" );
41}
42
43QString QgsFillNoDataAlgorithm::groupId() const
44{
45 return QStringLiteral( "rastertools" );
46}
47
48void QgsFillNoDataAlgorithm::initAlgorithm( const QVariantMap & )
49{
50 addParameter( new QgsProcessingParameterRasterLayer( QStringLiteral( "INPUT" ), QStringLiteral( "Raster input" ) ) );
51 addParameter( new QgsProcessingParameterBand( QStringLiteral( "BAND" ), QObject::tr( "Band Number" ), 1, QStringLiteral( "INPUT" ) ) );
52 addParameter( new QgsProcessingParameterNumber( QStringLiteral( "FILL_VALUE" ), QObject::tr( "Fill value" ), Qgis::ProcessingNumberParameterType::Double, 1, false ) );
53 addParameter( new QgsProcessingParameterRasterDestination( QStringLiteral( "OUTPUT" ), QObject::tr( "Output raster" ) ) );
54}
55
56QString QgsFillNoDataAlgorithm::shortHelpString() const
57{
58 return QObject::tr( "This algorithm resets the NoData values in the input raster "
59 "to a chosen value, resulting in a raster dataset with no NoData pixels. "
60 "This value can be set by the user using the Fill value parameter. "
61 "The algorithm respects the input raster data type (eg. a floating point fill value will be truncated "
62 "when applied to an integer raster)." );
63}
64
65QgsFillNoDataAlgorithm *QgsFillNoDataAlgorithm::createInstance() const
66{
67 return new QgsFillNoDataAlgorithm();
68}
69
70bool QgsFillNoDataAlgorithm::prepareAlgorithm( const QVariantMap &parameters, QgsProcessingContext &context, QgsProcessingFeedback *feedback )
71{
72 Q_UNUSED( feedback );
73 mInputRaster = parameterAsRasterLayer( parameters, QStringLiteral( "INPUT" ), context );
74 mFillValue = parameterAsDouble( parameters, QStringLiteral( "FILL_VALUE" ), context );
75
76 if ( !mInputRaster )
77 throw QgsProcessingException( invalidRasterError( parameters, QStringLiteral( "INPUT" ) ) );
78
79 mBand = parameterAsInt( parameters, QStringLiteral( "BAND" ), context );
80 if ( mBand < 1 || mBand > mInputRaster->bandCount() )
81 throw QgsProcessingException( QObject::tr( "Invalid band number for BAND (%1): Valid values for input raster are 1 to %2" ).arg( mBand ).arg( mInputRaster->bandCount() ) );
82
83 mInterface.reset( mInputRaster->dataProvider()->clone() );
84 mInputNoDataValue = mInputRaster->dataProvider()->sourceNoDataValue( mBand );
85 mExtent = mInputRaster->extent();
86 mLayerWidth = mInputRaster->width();
87 mLayerHeight = mInputRaster->height();
88 mCrs = mInputRaster->crs();
89 mNbCellsXProvider = mInterface->xSize();
90 mNbCellsYProvider = mInterface->ySize();
91 return true;
92}
93
94QVariantMap QgsFillNoDataAlgorithm::processAlgorithm( const QVariantMap &parameters, QgsProcessingContext &context, QgsProcessingFeedback *feedback )
95{
96 //test if input dataset has NoData
97 if ( !mInputRaster->dataProvider()->sourceHasNoDataValue( mBand ) )
98 feedback->reportError( QObject::tr( "Input raster has no NoData values. There exist no NoData cells to fill." ), false );
99
100 //prepare output dataset
101 const QString outputFile = parameterAsOutputLayer( parameters, QStringLiteral( "OUTPUT" ), context );
102 const QFileInfo fi( outputFile );
103 const QString outputFormat = QgsRasterFileWriter::driverForExtension( fi.suffix() );
104 std::unique_ptr< QgsRasterFileWriter > writer = std::make_unique< QgsRasterFileWriter >( outputFile );
105 writer->setOutputProviderKey( QStringLiteral( "gdal" ) );
106 writer->setOutputFormat( outputFormat );
107 std::unique_ptr<QgsRasterDataProvider > provider( writer->createOneBandRaster( mInterface->dataType( mBand ), mNbCellsXProvider, mNbCellsYProvider, mExtent, mCrs ) );
108 if ( !provider )
109 throw QgsProcessingException( QObject::tr( "Could not create raster output: %1" ).arg( outputFile ) );
110 if ( !provider->isValid() )
111 throw QgsProcessingException( QObject::tr( "Could not create raster output %1: %2" ).arg( outputFile, provider->error().message( QgsErrorMessage::Text ) ) );
112
113 //prepare output provider
114 QgsRasterDataProvider *destinationRasterProvider;
115 destinationRasterProvider = provider.get();
116 destinationRasterProvider->setEditable( true );
117
120 const int nbBlocksWidth = static_cast< int >( std::ceil( 1.0 * mLayerWidth / maxWidth ) );
121 const int nbBlocksHeight = static_cast< int >( std::ceil( 1.0 * mLayerHeight / maxHeight ) );
122 const int nbBlocks = nbBlocksWidth * nbBlocksHeight;
123
124 QgsRasterIterator iter( mInterface.get() );
125 iter.startRasterRead( mBand, mLayerWidth, mLayerHeight, mExtent );
126 int iterLeft = 0;
127 int iterTop = 0;
128 int iterCols = 0;
129 int iterRows = 0;
130 std::unique_ptr< QgsRasterBlock > filledRasterBlock;
131 while ( iter.readNextRasterPart( mBand, iterCols, iterRows, filledRasterBlock, iterLeft, iterTop ) )
132 {
133 if ( feedback )
134 feedback->setProgress( 100 * ( ( iterTop / maxHeight * nbBlocksWidth ) + iterLeft / maxWidth ) / nbBlocks );
135
136 if ( feedback && feedback->isCanceled() )
137 break;
138
139 if ( !filledRasterBlock->hasNoDataValue() )
140 {
141 destinationRasterProvider->writeBlock( filledRasterBlock.get(), mBand, iterLeft, iterTop );
142 continue;
143 }
144
145 for ( int row = 0; row < iterRows; row++ )
146 {
147 if ( feedback && feedback->isCanceled() )
148 break;
149 for ( int column = 0; column < iterCols; column++ )
150 {
151 if ( filledRasterBlock->isNoData( row, column ) )
152 filledRasterBlock->setValue( row, column, mFillValue );
153 }
154 }
155 destinationRasterProvider->writeBlock( filledRasterBlock.get(), mBand, iterLeft, iterTop );
156 }
157 destinationRasterProvider->setEditable( false );
158
159 QVariantMap outputs;
160 outputs.insert( QStringLiteral( "OUTPUT" ), outputFile );
161 return outputs;
162}
163
164
bool isCanceled() const
Tells whether the operation has been canceled already.
Definition qgsfeedback.h:53
void setProgress(double progress)
Sets the current progress for the feedback object.
Definition qgsfeedback.h:61
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 reportError(const QString &error, bool fatalError=false)
Reports that the algorithm encountered an error while executing.
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.
Base class for raster data providers.
bool writeBlock(QgsRasterBlock *block, int band, int xOffset=0, int yOffset=0)
Writes pixel data from a raster block into the provider data source.
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.