qgsalgorithmfillnodata.cpp

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/***************************************************************************
                         qgsalgorithmfillnodata.cpp
                         ---------------------
    begin                : January 2020
    copyright            : (C) 2020 by Clemens Raffler
    email                : clemens dot raffler at gmail dot com
 ***************************************************************************/
 
/***************************************************************************
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 ***************************************************************************/
 
#include "qgsalgorithmfillnodata.h"
#include "qgsrasterfilewriter.h"
 
 
QString QgsFillNoDataAlgorithm::name() const
{
  return QStringLiteral( "fillnodata" );
}
 
QString QgsFillNoDataAlgorithm::displayName() const
{
  return QObject::tr( "Fill NoData cells" );
}
 
QStringList QgsFillNoDataAlgorithm::tags() const
{
  return QObject::tr( "data,cells,fill,set" ).split( ',' );
}
 
QString QgsFillNoDataAlgorithm::group() const
{
  return QObject::tr( "Raster tools" );
}
 
QString QgsFillNoDataAlgorithm::groupId() const
{
  return QStringLiteral( "rastertools" );
}
 
void QgsFillNoDataAlgorithm::initAlgorithm( const QVariantMap & )
{
  addParameter( new QgsProcessingParameterRasterLayer( QStringLiteral( "INPUT" ), QStringLiteral( "Raster input" ) ) );
  addParameter( new QgsProcessingParameterBand( QStringLiteral( "BAND" ), QObject::tr( "Band Number" ), 1, QStringLiteral( "INPUT" ) ) );
  addParameter( new QgsProcessingParameterNumber( QStringLiteral( "FILL_VALUE" ), QObject::tr( "Fill value" ), Qgis::ProcessingNumberParameterType::Double, 1, false ) );
  addParameter( new QgsProcessingParameterRasterDestination( QStringLiteral( "OUTPUT" ), QObject::tr( "Output raster" ) ) );
}
 
QString QgsFillNoDataAlgorithm::shortHelpString() const
{
  return QObject::tr( "This algorithm resets the NoData values in the input raster "
                      "to a chosen value, resulting in a raster dataset with no NoData pixels. "
                      "This value can be set by the user using the Fill value parameter. "
                      "The algorithm respects the input raster data type (eg. a floating point fill value will be truncated "
                      "when applied to an integer raster)." );
}
 
QgsFillNoDataAlgorithm *QgsFillNoDataAlgorithm::createInstance() const
{
  return new QgsFillNoDataAlgorithm();
}
 
bool QgsFillNoDataAlgorithm::prepareAlgorithm( const QVariantMap &parameters, QgsProcessingContext &context, QgsProcessingFeedback *feedback )
{
  Q_UNUSED( feedback );
  mInputRaster = parameterAsRasterLayer( parameters, QStringLiteral( "INPUT" ), context );
  mFillValue = parameterAsDouble( parameters, QStringLiteral( "FILL_VALUE" ), context );
 
  if ( !mInputRaster )
    throw QgsProcessingException( invalidRasterError( parameters, QStringLiteral( "INPUT" ) ) );
 
  mBand = parameterAsInt( parameters, QStringLiteral( "BAND" ), context );
  if ( mBand < 1 || mBand > mInputRaster->bandCount() )
    throw QgsProcessingException( QObject::tr( "Invalid band number for BAND (%1): Valid values for input raster are 1 to %2" ).arg( mBand ).arg( mInputRaster->bandCount() ) );
 
  mInterface.reset( mInputRaster->dataProvider()->clone() );
  mInputNoDataValue = mInputRaster->dataProvider()->sourceNoDataValue( mBand );
  mExtent = mInputRaster->extent();
  mLayerWidth = mInputRaster->width();
  mLayerHeight = mInputRaster->height();
  mCrs = mInputRaster->crs();
  mNbCellsXProvider = mInterface->xSize();
  mNbCellsYProvider = mInterface->ySize();
  return true;
}
 
QVariantMap QgsFillNoDataAlgorithm::processAlgorithm( const QVariantMap &parameters, QgsProcessingContext &context, QgsProcessingFeedback *feedback )
{
  //test if input dataset has NoData
  if ( !mInputRaster->dataProvider()->sourceHasNoDataValue( mBand ) )
    feedback->reportError( QObject::tr( "Input raster has no NoData values. There exist no NoData cells to fill." ), false );
 
  //prepare output dataset
  const QString outputFile = parameterAsOutputLayer( parameters, QStringLiteral( "OUTPUT" ), context );
  const QFileInfo fi( outputFile );
  const QString outputFormat = QgsRasterFileWriter::driverForExtension( fi.suffix() );
  std::unique_ptr< QgsRasterFileWriter > writer = std::make_unique< QgsRasterFileWriter >( outputFile );
  writer->setOutputProviderKey( QStringLiteral( "gdal" ) );
  writer->setOutputFormat( outputFormat );
  std::unique_ptr<QgsRasterDataProvider > provider( writer->createOneBandRaster( mInterface->dataType( mBand ), mNbCellsXProvider, mNbCellsYProvider, mExtent, mCrs ) );
  if ( !provider )
    throw QgsProcessingException( QObject::tr( "Could not create raster output: %1" ).arg( outputFile ) );
  if ( !provider->isValid() )
    throw QgsProcessingException( QObject::tr( "Could not create raster output %1: %2" ).arg( outputFile, provider->error().message( QgsErrorMessage::Text ) ) );
 
  //prepare output provider
  QgsRasterDataProvider *destinationRasterProvider;
  destinationRasterProvider = provider.get();
  destinationRasterProvider->setEditable( true );
 
  const int maxWidth = QgsRasterIterator::DEFAULT_MAXIMUM_TILE_WIDTH;
  const int maxHeight = QgsRasterIterator::DEFAULT_MAXIMUM_TILE_HEIGHT;
  const int nbBlocksWidth = static_cast< int >( std::ceil( 1.0 * mLayerWidth / maxWidth ) );
  const int nbBlocksHeight = static_cast< int >( std::ceil( 1.0 * mLayerHeight / maxHeight ) );
  const int nbBlocks = nbBlocksWidth * nbBlocksHeight;
 
  QgsRasterIterator iter( mInterface.get() );
  iter.startRasterRead( mBand, mLayerWidth, mLayerHeight, mExtent );
  int iterLeft = 0;
  int iterTop = 0;
  int iterCols = 0;
  int iterRows = 0;
  std::unique_ptr< QgsRasterBlock > filledRasterBlock;
  while ( iter.readNextRasterPart( mBand, iterCols, iterRows, filledRasterBlock, iterLeft, iterTop ) )
  {
    if ( feedback )
      feedback->setProgress( 100 * ( ( iterTop / maxHeight * nbBlocksWidth ) + iterLeft / maxWidth ) / nbBlocks );
 
    if ( feedback && feedback->isCanceled() )
      break;
 
    if ( !filledRasterBlock->hasNoDataValue() )
    {
      destinationRasterProvider->writeBlock( filledRasterBlock.get(), mBand, iterLeft, iterTop );
      continue;
    }
 
    for ( int row = 0; row < iterRows; row++ )
    {
      if ( feedback && feedback->isCanceled() )
        break;
      for ( int column = 0; column < iterCols; column++ )
      {
        if ( filledRasterBlock->isNoData( row, column ) )
          filledRasterBlock->setValue( row, column, mFillValue );
      }
    }
    destinationRasterProvider->writeBlock( filledRasterBlock.get(), mBand, iterLeft, iterTop );
  }
  destinationRasterProvider->setEditable( false );
 
  QVariantMap outputs;
  outputs.insert( QStringLiteral( "OUTPUT" ), outputFile );
  return outputs;
}