Add export quality slider for jpeg/jpg

python/PyQt6/core/auto_additions/qgslayoutexporter.py

@@ -13,7 +13,7 @@
 except NameError:
     pass
 try:
-    QgsLayoutExporter.ImageExportSettings.__attribute_docs__ = {'dpi': 'Resolution to export layout at. If dpi <= 0 the default layout dpi will be used.', 'imageSize': "Manual size in pixels for output image. If imageSize is not\nset then it will be automatically calculated based on the\noutput dpi and layout size.\n\nIf cropToContents is ``True`` then imageSize has no effect.\n\nBe careful when specifying manual sizes if pages in the layout\nhave differing sizes! It's likely not going to give a reasonable\noutput in this case, and the automatic dpi-based image size should be\nused instead.", 'cropToContents': 'Set to ``True`` if image should be cropped so only parts of the layout\ncontaining items are exported.', 'cropMargins': 'Crop to content margins, in pixels. These margins will be added\nto the bounds of the exported layout if cropToContents is ``True``.', 'pages': 'List of specific pages to export, or an empty list to\nexport all pages.\n\nPage numbers are 0 index based, so the first page in the\nlayout corresponds to page 0.', 'generateWorldFile': 'Set to ``True`` to generate an external world file alongside\nexported images.', 'exportMetadata': "Indicates whether image export should include metadata generated\nfrom the layout's project's metadata.\n\n.. versionadded:: 3.2", 'flags': 'Layout context flags, which control how the export will be created.', 'predefinedMapScales': 'A list of predefined scales to use with the layout. This is used\nfor maps which are set to the predefined atlas scaling mode.\n\n.. versionadded:: 3.10'}
+    QgsLayoutExporter.ImageExportSettings.__attribute_docs__ = {'dpi': 'Resolution to export layout at. If dpi <= 0 the default layout dpi will be used.', 'imageSize': "Manual size in pixels for output image. If imageSize is not\nset then it will be automatically calculated based on the\noutput dpi and layout size.\n\nIf cropToContents is ``True`` then imageSize has no effect.\n\nBe careful when specifying manual sizes if pages in the layout\nhave differing sizes! It's likely not going to give a reasonable\noutput in this case, and the automatic dpi-based image size should be\nused instead.", 'cropToContents': 'Set to ``True`` if image should be cropped so only parts of the layout\ncontaining items are exported.', 'cropMargins': 'Crop to content margins, in pixels. These margins will be added\nto the bounds of the exported layout if cropToContents is ``True``.', 'pages': 'List of specific pages to export, or an empty list to\nexport all pages.\n\nPage numbers are 0 index based, so the first page in the\nlayout corresponds to page 0.', 'generateWorldFile': 'Set to ``True`` to generate an external world file alongside\nexported images.', 'exportMetadata': "Indicates whether image export should include metadata generated\nfrom the layout's project's metadata.\n\n.. versionadded:: 3.2", 'flags': 'Layout context flags, which control how the export will be created.', 'predefinedMapScales': 'A list of predefined scales to use with the layout. This is used\nfor maps which are set to the predefined atlas scaling mode.\n\n.. versionadded:: 3.10', 'quality': 'Image quality, typically used for JPEG compression (whose quality ranges from 1 to 100)\nif quality is set to -1, the default quality will be used.\n\n.. versionadded:: 3.42'}
     QgsLayoutExporter.ImageExportSettings.__doc__ = """Contains settings relating to exporting layouts to raster images"""
     QgsLayoutExporter.ImageExportSettings.__group__ = ['layout']
 except NameError:

python/PyQt6/core/auto_generated/layout/qgslayoutexporter.sip.in

@@ -24,6 +24,7 @@ Handles rendering and exports of layouts to various formats.
 
 
 
+
     struct PageExportDetails
     {
       QString directory;
@@ -142,6 +143,9 @@ Returns the rendered image, or a null QImage if the image does not fit into avai
 
       QVector<qreal> predefinedMapScales;
 
+
+      int quality;
+
     };
 
     ExportResult exportToImage( const QString &filePath, const QgsLayoutExporter::ImageExportSettings &settings );

python/core/auto_additions/qgslayoutexporter.py

@@ -6,7 +6,7 @@
 except NameError:
     pass
 try:
-    QgsLayoutExporter.ImageExportSettings.__attribute_docs__ = {'dpi': 'Resolution to export layout at. If dpi <= 0 the default layout dpi will be used.', 'imageSize': "Manual size in pixels for output image. If imageSize is not\nset then it will be automatically calculated based on the\noutput dpi and layout size.\n\nIf cropToContents is ``True`` then imageSize has no effect.\n\nBe careful when specifying manual sizes if pages in the layout\nhave differing sizes! It's likely not going to give a reasonable\noutput in this case, and the automatic dpi-based image size should be\nused instead.", 'cropToContents': 'Set to ``True`` if image should be cropped so only parts of the layout\ncontaining items are exported.', 'cropMargins': 'Crop to content margins, in pixels. These margins will be added\nto the bounds of the exported layout if cropToContents is ``True``.', 'pages': 'List of specific pages to export, or an empty list to\nexport all pages.\n\nPage numbers are 0 index based, so the first page in the\nlayout corresponds to page 0.', 'generateWorldFile': 'Set to ``True`` to generate an external world file alongside\nexported images.', 'exportMetadata': "Indicates whether image export should include metadata generated\nfrom the layout's project's metadata.\n\n.. versionadded:: 3.2", 'flags': 'Layout context flags, which control how the export will be created.', 'predefinedMapScales': 'A list of predefined scales to use with the layout. This is used\nfor maps which are set to the predefined atlas scaling mode.\n\n.. versionadded:: 3.10'}
+    QgsLayoutExporter.ImageExportSettings.__attribute_docs__ = {'dpi': 'Resolution to export layout at. If dpi <= 0 the default layout dpi will be used.', 'imageSize': "Manual size in pixels for output image. If imageSize is not\nset then it will be automatically calculated based on the\noutput dpi and layout size.\n\nIf cropToContents is ``True`` then imageSize has no effect.\n\nBe careful when specifying manual sizes if pages in the layout\nhave differing sizes! It's likely not going to give a reasonable\noutput in this case, and the automatic dpi-based image size should be\nused instead.", 'cropToContents': 'Set to ``True`` if image should be cropped so only parts of the layout\ncontaining items are exported.', 'cropMargins': 'Crop to content margins, in pixels. These margins will be added\nto the bounds of the exported layout if cropToContents is ``True``.', 'pages': 'List of specific pages to export, or an empty list to\nexport all pages.\n\nPage numbers are 0 index based, so the first page in the\nlayout corresponds to page 0.', 'generateWorldFile': 'Set to ``True`` to generate an external world file alongside\nexported images.', 'exportMetadata': "Indicates whether image export should include metadata generated\nfrom the layout's project's metadata.\n\n.. versionadded:: 3.2", 'flags': 'Layout context flags, which control how the export will be created.', 'predefinedMapScales': 'A list of predefined scales to use with the layout. This is used\nfor maps which are set to the predefined atlas scaling mode.\n\n.. versionadded:: 3.10', 'quality': 'Image quality, typically used for JPEG compression (whose quality ranges from 1 to 100)\nif quality is set to -1, the default quality will be used.\n\n.. versionadded:: 3.42'}
     QgsLayoutExporter.ImageExportSettings.__doc__ = """Contains settings relating to exporting layouts to raster images"""
     QgsLayoutExporter.ImageExportSettings.__group__ = ['layout']
 except NameError:

python/core/auto_generated/layout/qgslayoutexporter.sip.in

@@ -24,6 +24,7 @@ Handles rendering and exports of layouts to various formats.
 
 
 
+
     struct PageExportDetails
     {
       QString directory;
@@ -142,6 +143,9 @@ Returns the rendered image, or a null QImage if the image does not fit into avai
 
       QVector<qreal> predefinedMapScales;
 
+
+      int quality;
+
     };
 
     ExportResult exportToImage( const QString &filePath, const QgsLayoutExporter::ImageExportSettings &settings );

src/app/layout/qgslayoutdesignerdialog.cpp

@@ -2296,7 +2296,7 @@ void QgsLayoutDesignerDialog::exportToRaster()
 
   QgsLayoutExporter::ImageExportSettings settings;
   QSize imageSize;
-  if ( !getRasterExportSettings( settings, imageSize ) )
+  if ( !getRasterExportSettings( settings, imageSize, fileNExt.second ) )
     return;
 
   mView->setPaintingEnabled( false );
@@ -2999,7 +2999,7 @@ void QgsLayoutDesignerDialog::exportAtlasToRaster()
 
   QgsLayoutExporter::ImageExportSettings settings;
   QSize imageSize;
-  if ( !getRasterExportSettings( settings, imageSize ) )
+  if ( !getRasterExportSettings( settings, imageSize, format ) )
     return;
 
   mView->setPaintingEnabled( false );
@@ -3532,7 +3532,7 @@ void QgsLayoutDesignerDialog::exportReportToRaster()
 
   QgsLayoutExporter::ImageExportSettings settings;
   QSize imageSize;
-  if ( !getRasterExportSettings( settings, imageSize ) )
+  if ( !getRasterExportSettings( settings, imageSize, fileNExt.second ) )
     return;
 
   mView->setPaintingEnabled( false );
@@ -4336,7 +4336,7 @@ bool QgsLayoutDesignerDialog::showFileSizeWarning()
   return true;
 }
 
-bool QgsLayoutDesignerDialog::getRasterExportSettings( QgsLayoutExporter::ImageExportSettings &settings, QSize &imageSize )
+bool QgsLayoutDesignerDialog::getRasterExportSettings( QgsLayoutExporter::ImageExportSettings &settings, QSize &imageSize, const QString &fileExtension )
 {
   QSizeF maxPageSize;
   bool hasUniformPageSizes = false;
@@ -4366,7 +4366,7 @@ bool QgsLayoutDesignerDialog::getRasterExportSettings( QgsLayoutExporter::ImageE
     antialias = mLayout->customProperty( QStringLiteral( "imageAntialias" ), true ).toBool();
   }
 
-  QgsLayoutImageExportOptionsDialog imageDlg( this );
+  QgsLayoutImageExportOptionsDialog imageDlg( this, fileExtension );
   imageDlg.setImageSize( maxPageSize );
   imageDlg.setResolution( dpi );
   imageDlg.setCropToContents( cropToContents );
@@ -4375,6 +4375,7 @@ bool QgsLayoutDesignerDialog::getRasterExportSettings( QgsLayoutExporter::ImageE
     imageDlg.setGenerateWorldFile( mLayout->customProperty( QStringLiteral( "exportWorldFile" ), false ).toBool() );
   imageDlg.setAntialiasing( antialias );
   imageDlg.setOpenAfterExporting( QgsLayoutExporter::settingOpenAfterExportingImage->value() );
+  imageDlg.setQuality( QgsLayoutExporter::settingImageQuality->value() );
 
   if ( !imageDlg.exec() )
     return false;
@@ -4409,6 +4410,12 @@ bool QgsLayoutDesignerDialog::getRasterExportSettings( QgsLayoutExporter::ImageE
   else
     settings.flags &= ~QgsLayoutRenderContext::FlagAntialiasing;
 
+  settings.quality = imageDlg.quality();
+  if ( settings.quality != -1 )
+  {
+    QgsLayoutExporter::settingImageQuality->setValue( imageDlg.quality() );
+  }
+
   return true;
 }
 

src/app/layout/qgslayoutdesignerdialog.h

@@ -564,7 +564,7 @@ class QgsLayoutDesignerDialog: public QMainWindow, public Ui::QgsLayoutDesignerB
     void showForceVectorWarning();
 
     bool showFileSizeWarning();
-    bool getRasterExportSettings( QgsLayoutExporter::ImageExportSettings &settings, QSize &imageSize );
+    bool getRasterExportSettings( QgsLayoutExporter::ImageExportSettings &settings, QSize &imageSize, const QString &fileExtension );
     bool getSvgExportSettings( QgsLayoutExporter::SvgExportSettings &settings );
     bool getPdfExportSettings( QgsLayoutExporter::PdfExportSettings &settings, bool allowGeospatialPdfExport = true, const QString &geospatialPdfReason = QString() );
 

src/core/layout/qgslayoutexporter.cpp

@@ -155,6 +155,7 @@ class LayoutItemHider
 const QgsSettingsEntryBool *QgsLayoutExporter::settingOpenAfterExportingImage = new QgsSettingsEntryBool( QStringLiteral( "open-after-exporting-image" ), QgsSettingsTree::sTreeLayout, false, QObject::tr( "Whether to open the exported image file with the default viewer after exporting a print layout" ) );
 const QgsSettingsEntryBool *QgsLayoutExporter::settingOpenAfterExportingPdf = new QgsSettingsEntryBool( QStringLiteral( "open-after-exporting-pdf" ), QgsSettingsTree::sTreeLayout, false, QObject::tr( "Whether to open the exported PDF file with the default viewer after exporting a print layout" ) );
 const QgsSettingsEntryBool *QgsLayoutExporter::settingOpenAfterExportingSvg = new QgsSettingsEntryBool( QStringLiteral( "open-after-exporting-svg" ), QgsSettingsTree::sTreeLayout, false, QObject::tr( "Whether to open the exported SVG file with the default viewer after exporting a print layout" ) );
+const QgsSettingsEntryInteger *QgsLayoutExporter::settingImageQuality = new QgsSettingsEntryInteger( QStringLiteral( "image-quality" ), QgsSettingsTree::sTreeLayout, 90, QObject::tr( "Image quality for lossy formats (e.g. JPEG)" ) );
 
 QgsLayoutExporter::QgsLayoutExporter( QgsLayout *layout )
   : mLayout( layout )
@@ -456,7 +457,7 @@ QgsLayoutExporter::ExportResult QgsLayoutExporter::exportToImage( const QString
       return MemoryError;
     }
 
-    if ( !saveImage( image, outputFilePath, pageDetails.extension, settings.exportMetadata ? mLayout->project() : nullptr ) )
+    if ( !saveImage( image, outputFilePath, pageDetails.extension, settings.exportMetadata ? mLayout->project() : nullptr, settings.quality ) )
     {
       mErrorFileName = outputFilePath;
       return FileError;
@@ -2216,13 +2217,17 @@ void QgsLayoutExporter::captureLabelingResults()
   }
 }
 
-bool QgsLayoutExporter::saveImage( const QImage &image, const QString &imageFilename, const QString &imageFormat, QgsProject *projectForMetadata )
+bool QgsLayoutExporter::saveImage( const QImage &image, const QString &imageFilename, const QString &imageFormat, QgsProject *projectForMetadata, int quality )
 {
   QImageWriter w( imageFilename, imageFormat.toLocal8Bit().constData() );
   if ( imageFormat.compare( QLatin1String( "tiff" ), Qt::CaseInsensitive ) == 0 || imageFormat.compare( QLatin1String( "tif" ), Qt::CaseInsensitive ) == 0 )
   {
     w.setCompression( 1 ); //use LZW compression
   }
+
+  // Set the quality for i.e. JPEG images. -1 means default quality.
+  w.setQuality( quality );
+
   if ( projectForMetadata )
   {
     w.setText( QStringLiteral( "Author" ), projectForMetadata->metadata().author() );

src/core/layout/qgslayoutexporter.h

@@ -41,6 +41,7 @@ class QgsAbstractLayoutIterator;
 class QgsFeedback;
 class QgsLabelingResults;
 class QgsSettingsEntryBool;
+class QgsSettingsEntryInteger;
 
 /**
  * \ingroup core
@@ -61,6 +62,9 @@ class CORE_EXPORT QgsLayoutExporter
     //! Settings entry - Whether to automatically open svgs after exporting them \since QGIS 3.34
     static const QgsSettingsEntryBool *settingOpenAfterExportingSvg SIP_SKIP;
 
+    //! Settings entry - Image quality for lossy formats \since QGIS 3.42
+    static const QgsSettingsEntryInteger *settingImageQuality SIP_SKIP;
+
     //! Contains details of a page being exported by the class
     struct PageExportDetails
     {
@@ -231,6 +235,14 @@ class CORE_EXPORT QgsLayoutExporter
        */
       QVector<qreal> predefinedMapScales;
 
+
+      /**
+       * Image quality, typically used for JPEG compression (whose quality ranges from 1 to 100)
+       * if quality is set to -1, the default quality will be used.
+       * \since QGIS 3.42
+       */
+      int quality = -1;
+
     };
 
     /**
@@ -719,7 +731,7 @@ class CORE_EXPORT QgsLayoutExporter
     /**
      * Saves an image to a file, possibly using format specific options (e.g. LZW compression for tiff)
     */
-    static bool saveImage( const QImage &image, const QString &imageFilename, const QString &imageFormat, QgsProject *projectForMetadata );
+    static bool saveImage( const QImage &image, const QString &imageFilename, const QString &imageFormat, QgsProject *projectForMetadata, int quality = -1 );
 
     /**
      * Computes a GDAL style geotransform for georeferencing a layout.

src/gui/layout/qgslayoutimageexportoptionsdialog.cpp

@@ -23,9 +23,12 @@
 
 #include <QCheckBox>
 #include <QPushButton>
+#include <QSpinBox>
+#include <QSlider>
 
-QgsLayoutImageExportOptionsDialog::QgsLayoutImageExportOptionsDialog( QWidget *parent, Qt::WindowFlags flags )
+QgsLayoutImageExportOptionsDialog::QgsLayoutImageExportOptionsDialog( QWidget *parent, const QString &fileExtension, Qt::WindowFlags flags )
   : QDialog( parent, flags )
+  , mFileExtension( fileExtension )
 {
   setupUi( this );
   connect( mWidthSpinBox, static_cast < void ( QSpinBox::* )( int ) > ( &QSpinBox::valueChanged ), this, &QgsLayoutImageExportOptionsDialog::mWidthSpinBox_valueChanged );
@@ -34,6 +37,16 @@ QgsLayoutImageExportOptionsDialog::QgsLayoutImageExportOptionsDialog( QWidget *p
 
   connect( mClipToContentGroupBox, &QGroupBox::toggled, this, &QgsLayoutImageExportOptionsDialog::clipToContentsToggled );
   connect( mHelpButtonBox, &QDialogButtonBox::helpRequested, this, &QgsLayoutImageExportOptionsDialog::showHelp );
+
+  const bool showQuality = shouldShowQuality();
+  mQualitySpinBox->setVisible( showQuality );
+  mQualitySlider->setVisible( showQuality );
+  mQualityLabel->setVisible( showQuality );
+  mQualityLabel->setText( tr( "%1 quality", "Image format" ).arg( mFileExtension.toUpper() ) );
+
+  connect( mQualitySpinBox, qOverload< int >( &QSpinBox::valueChanged ), mQualitySlider, &QSlider::setValue );
+  connect( mQualitySlider, &QSlider::valueChanged, mQualitySpinBox, &QSpinBox::setValue );
+
   QgsGui::enableAutoGeometryRestore( this );
 }
 
@@ -142,6 +155,20 @@ void QgsLayoutImageExportOptionsDialog::setOpenAfterExporting( bool enabled )
   mOpenAfterExportingCheckBox->setChecked( enabled );
 }
 
+int QgsLayoutImageExportOptionsDialog::quality() const
+{
+  if ( !shouldShowQuality() )
+  {
+    return -1;
+  }
+  return mQualitySpinBox->value();
+}
+
+void QgsLayoutImageExportOptionsDialog::setQuality( int quality )
+{
+  mQualitySpinBox->setValue( quality );
+}
+
 void QgsLayoutImageExportOptionsDialog::mWidthSpinBox_valueChanged( int value )
 {
   mHeightSpinBox->blockSignals( true );
@@ -201,3 +228,16 @@ void QgsLayoutImageExportOptionsDialog::showHelp()
 {
   QgsHelp::openHelp( QStringLiteral( "print_composer/create_output.html" ) );
 }
+
+bool QgsLayoutImageExportOptionsDialog::shouldShowQuality() const
+{
+  const QStringList validExtensions = { "jpeg", "jpg" };
+  for ( const QString &ext : validExtensions )
+  {
+    if ( mFileExtension.toLower() == ext )
+    {
+      return true;
+    }
+  }
+  return false;
+}

src/gui/layout/qgslayoutimageexportoptionsdialog.h

@@ -41,9 +41,10 @@ class GUI_EXPORT QgsLayoutImageExportOptionsDialog: public QDialog, private Ui::
     /**
      * Constructor for QgsLayoutImageExportOptionsDialog
      * \param parent parent widget
+     * \param fileExtension output image file extension
      * \param flags window flags
      */
-    QgsLayoutImageExportOptionsDialog( QWidget *parent = nullptr, Qt::WindowFlags flags = Qt::WindowFlags() );
+    QgsLayoutImageExportOptionsDialog( QWidget *parent = nullptr, const QString &fileExtension = QString(), Qt::WindowFlags flags = Qt::WindowFlags() );
 
     /**
      * Sets the initial resolution displayed in the dialog.
@@ -138,6 +139,12 @@ class GUI_EXPORT QgsLayoutImageExportOptionsDialog: public QDialog, private Ui::
     //! Returns whether the pdf should be opened after exporting it
     bool openAfterExporting() const;
 
+
+    //! Sets the image quality (for JPEG)
+    void setQuality( int quality );
+    //! Returns the image quality
+    int quality() const;
+
   private slots:
 
     void mWidthSpinBox_valueChanged( int value );
@@ -148,7 +155,9 @@ class GUI_EXPORT QgsLayoutImageExportOptionsDialog: public QDialog, private Ui::
 
   private:
 
+    bool shouldShowQuality() const;
     QSizeF mImageSize;
+    QString mFileExtension;
 
 
 };