Add an SVG export option to store pictures smaller

An SVG keeps every picture at full resolution, whatever size it is
drawn at: a folio with 22 phone photos shown at a tenth of their size
gave a 270 MB SVG and took 65 s to write, most of it compressing the
photos again.

The export dialog gets "SVG: smaller pictures" (off by default, kept
with the other export settings), and --export-svg gets
--svg-small-pictures. With it, a picture is stored at four times the
size it is drawn at when that is smaller than the picture; smaller
pictures stay whole. Four times is about 375 dpi on a printed folio.

The exporter sets Diagram::smallPictures() for its own drawing only,
so screen, print, PDF and PNG are unchanged. It is not part of
applyProperties(), which every format uses.

On that project: --export-svg 84.9 s -> 34.5 s (opening is 20 s of
both), 270 MB -> 57 MB, peak memory 2.45 -> 1.86 GB. Rendered at twice
the folio size, the two SVGs differ by more than 32/255 on 0.23 % of
pixels, along photo detail.

tst_svgsmallpictures: an 800x600 picture drawn at 0.1 is stored at
320x240 with the option, through --export-svg and through the
dialog's QPicture route, and at 800x600 without it; a 40x30 picture
stays whole. It fails when the factor is changed.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

sources/cli_export.cpp

@@ -283,7 +283,8 @@ int exportPdf(QETProject &project, const QString &output,
 }
 
 int exportImages(QETProject &project, const QString &format,
-				 const QString &out_dir, bool showTerminals = false)
+				 const QString &out_dir, bool showTerminals = false,
+				 bool svgSmallPictures = false)
 {
 	const QList<Diagram *> diagrams = project.diagrams();
 	if (diagrams.isEmpty()) {
@@ -306,8 +307,10 @@ int exportImages(QETProject &project, const QString &format,
 			gen.setViewBox(QRect(0, 0, r.width(), r.height()));
 			gen.setTitle(diagram->title());
 			QPainter painter(&gen);
+			diagram->setSmallPictures(svgSmallPictures);
 			renderDiagram(diagram, painter, QRectF(QPointF(0, 0), r.size()),
 						 showTerminals);
+			diagram->setSmallPictures(false);
 			painter.end();
 		} else { // png
 			QImage image(r.size(), QImage::Format_ARGB32);
@@ -1014,6 +1017,7 @@ int run(const QStringList &args)
 	const bool showTerminals = filtered.removeAll("--show-terminals") > 0;
 	const bool dxfBlocks = filtered.removeAll("--dxf-blocks") > 0;
 	const bool dxfAttributes = filtered.removeAll("--dxf-attributes") > 0;
+	const bool svgSmallPictures = filtered.removeAll("--svg-small-pictures") > 0;
 	// --no-slaves and --no-junctions leave rows out of --export-bom.
 	const bool includeSlaves = filtered.removeAll("--no-slaves") == 0;
 	const bool includeJunctions = filtered.removeAll("--no-junctions") == 0;
@@ -1085,7 +1089,8 @@ int run(const QStringList &args)
 		return resaveProject(project, output);
 	if (format == "settb")
 		return setTitleBlock(project, output, rest.mid(2));
-	return exportImages(project, format, output, showTerminals);
+	return exportImages(project, format, output, showTerminals,
+						svgSmallPictures);
 }
 
 } // namespace CLIExport

sources/cli_export.h

@@ -44,7 +44,7 @@ namespace CLIExport {
 		Usage:
 		  qelectrotech --export-pdf     <project.qet> <output.pdf> [--show-terminals]
 		  qelectrotech --export-png     <project.qet> <output_dir> [--show-terminals]
-		  qelectrotech --export-svg     <project.qet> <output_dir> [--show-terminals]
+		  qelectrotech --export-svg     <project.qet> <output_dir> [--show-terminals] [--svg-small-pictures]
 		  qelectrotech --export-dxf     <project.qet> <output_dir> [--show-terminals] [--dxf-blocks] [--dxf-attributes]
 		  qelectrotech --export-cables  <project.qet> <output.csv>
 		  qelectrotech --export-wires   <project.qet> <output.csv>
@@ -71,6 +71,9 @@ namespace CLIExport {
 		--dxf-attributes: as --dxf-blocks, and a symbol's texts (its label,
 		      function...) are attributes of its INSERT. LibreCAD does not
 		      show attributes.
+		--svg-small-pictures: in an SVG, each picture at most four times the
+		      size it is drawn at instead of its full resolution: a much
+		      smaller file, still sharp when printed.
 		cables: wiring list (one row per conductor) as CSV.
 		wires: list of distinct wire numbers as CSV.
 		bom: bill of materials (one row per element) as CSV.

sources/diagram.h

@@ -133,6 +133,7 @@ class Diagram : public QGraphicsScene
 		bool draw_terminals_;
 		bool draw_terminal_names_;
 		bool draw_colored_conductors_;
+		bool m_small_pictures = false;
 
 		QString m_conductors_autonum_name;
 		DiagramEventInterface *m_event_interface;
@@ -284,6 +285,11 @@ class Diagram : public QGraphicsScene
 		void setDrawTerminalNames(bool);
 		bool drawColoredConductors() const;
 		void setDrawColoredConductors(bool);
+			/// While true, pictures draw a copy of a few times the size
+			/// they are drawn at, not their full resolution (SVG export,
+			/// ExportProperties::svg_small_pictures)
+		bool smallPictures() const {return m_small_pictures;}
+		void setSmallPictures(bool small) {m_small_pictures = small;}
 	
 		QString title() const;
 		bool toPaintDevice(QPaintDevice &, int = -1, int = -1,

sources/exportdialog.cpp

@@ -417,12 +417,14 @@ void ExportDialog::generateSvg(
 	
 	// genere une QPicture a partir du schema
 	QPicture picture;
+	diagram -> setSmallPictures(epw -> exportProperties().svg_small_pictures);
 	diagram -> toPaintDevice(
 		picture,
 		width,
 		height,
 		keep_aspect_ratio ? Qt::KeepAspectRatio : Qt::IgnoreAspectRatio
 	);
+	diagram -> setSmallPictures(false);
 	
 	// "joue" la QPicture sur un QSvgGenerator
 	QSvgGenerator svg_engine;

sources/exportproperties.cpp

@@ -39,6 +39,7 @@ ExportProperties::ExportProperties() :
 	draw_colored_conductors(true),
 	dxf_blocks(false),
 	dxf_attributes(false),
+	svg_small_pictures(false),
 	exported_area(QET::BorderArea)
 {
 }
@@ -83,6 +84,8 @@ void ExportProperties::toSettings(QSettings &settings,
 			  dxf_blocks);
 	settings.setValue(prefix % "dxfattributes",
 			  dxf_attributes);
+	settings.setValue(prefix % "svgsmallpictures",
+			  svg_small_pictures);
 	settings.setValue(prefix % "area",
 			  QET::diagramAreaToString(exported_area));
 }
@@ -125,6 +128,8 @@ void ExportProperties::fromSettings(QSettings &settings,
 				    false).toBool();
 	dxf_attributes = settings.value(prefix % "dxfattributes",
 					false).toBool();
+	svg_small_pictures = settings.value(prefix % "svgsmallpictures",
+					    false).toBool();
 
 	exported_area  = QET::diagramAreaFromString(
 				settings.value(

sources/exportproperties.h

@@ -52,6 +52,7 @@ class ExportProperties {
 	bool draw_colored_conductors;   ///< Whether to render conductors colors
 	bool dxf_blocks;                ///< DXF: each symbol as a block, placed with an INSERT
 	bool dxf_attributes;            ///< DXF, with dxf_blocks: a symbol's texts as attributes of its INSERT
+	bool svg_small_pictures;        ///< SVG: pictures at most 4x the size they are drawn, not full resolution
 	QET::DiagramArea exported_area; ///< Area of diagrams to be rendered
 };
 #endif

sources/exportpropertieswidget.cpp

@@ -68,6 +68,7 @@ ExportProperties ExportPropertiesWidget::exportProperties() const
 	export_properties.draw_colored_conductors = draw_colored_conductors -> isChecked();
 	export_properties.dxf_blocks              = dxf_blocks -> isChecked();
 	export_properties.dxf_attributes          = dxf_attributes -> isChecked();
+	export_properties.svg_small_pictures      = svg_small_pictures -> isChecked();
 	export_properties.exported_area           = export_border -> isChecked() ? QET::BorderArea : QET::ElementsArea;
 	
 	return(export_properties);
@@ -94,6 +95,7 @@ void ExportPropertiesWidget::setExportProperties(const ExportProperties &export_
 	dxf_blocks              -> setChecked(export_properties.dxf_blocks);
 	dxf_attributes          -> setChecked(export_properties.dxf_attributes);
 	dxf_attributes          -> setEnabled(export_properties.dxf_blocks);
+	svg_small_pictures      -> setChecked(export_properties.svg_small_pictures);
 	
 	if (export_properties.exported_area == QET::BorderArea) {
 		export_border -> setChecked(true);
@@ -125,6 +127,7 @@ void ExportPropertiesWidget::setPrintingMode(bool mode) {
 	export_border       -> setVisible(!mode);
 	export_elements     -> setVisible(!mode);
 	draw_bg_transparent -> setVisible(!mode);
+	svg_small_pictures  -> setVisible(!mode);
 }
 
 /**
@@ -235,6 +238,11 @@ void ExportPropertiesWidget::build()
 	dxf_attributes -> setToolTip(tr("A symbol's texts (label, function...) become attributes of its block. LibreCAD does not show attributes."));
 	optionshlayout -> addWidget(dxf_attributes, 5, 1);
 	connect(dxf_blocks, &QCheckBox::toggled, dxf_attributes, &QCheckBox::setEnabled);
+
+	// pictures not at full resolution in an SVG: a much smaller file
+	svg_small_pictures = new QCheckBox(tr("SVG: smaller pictures"), groupbox_options);
+	svg_small_pictures -> setToolTip(tr("Pictures are stored at four times the size they have on the folio instead of their full resolution: a much smaller file, still sharp when printed"));
+	optionshlayout -> addWidget(svg_small_pictures, 5, 0);
 	
 	vboxLayout -> addWidget(groupbox_options);
 	
@@ -252,6 +260,7 @@ void ExportPropertiesWidget::build()
 	setTabOrder(draw_colored_conductors, draw_bg_transparent);
 	setTabOrder(draw_bg_transparent, dxf_blocks);
 	setTabOrder(dxf_blocks, dxf_attributes);
+	setTabOrder(draw_bg_transparent, svg_small_pictures);
 	
 	// connexion du bouton permettant le choix du repertoire
 	connect(button_browse, &QPushButton::released, this, &ExportPropertiesWidget::slot_chooseADirectory);	
@@ -269,6 +278,7 @@ void ExportPropertiesWidget::build()
 	connect(draw_colored_conductors, &QCheckBox::stateChanged, this, &ExportPropertiesWidget::optionChanged);
 	connect(dxf_blocks, &QCheckBox::stateChanged, this, &ExportPropertiesWidget::optionChanged);
 	connect(dxf_attributes, &QCheckBox::stateChanged, this, &ExportPropertiesWidget::optionChanged);
+	connect(svg_small_pictures, &QCheckBox::stateChanged, this, &ExportPropertiesWidget::optionChanged);
 #else
 	connect(draw_grid, &QCheckBox::checkStateChanged, this, &ExportPropertiesWidget::optionChanged);
 	connect(draw_border, &QCheckBox::checkStateChanged, this, &ExportPropertiesWidget::optionChanged);
@@ -279,5 +289,6 @@ void ExportPropertiesWidget::build()
 	connect(draw_colored_conductors, &QCheckBox::checkStateChanged, this, &ExportPropertiesWidget::optionChanged);
 	connect(dxf_blocks, &QCheckBox::checkStateChanged, this, &ExportPropertiesWidget::optionChanged);
 	connect(dxf_attributes, &QCheckBox::checkStateChanged, this, &ExportPropertiesWidget::optionChanged);
+	connect(svg_small_pictures, &QCheckBox::checkStateChanged, this, &ExportPropertiesWidget::optionChanged);
 #endif
 }

sources/exportpropertieswidget.h

@@ -67,6 +67,7 @@ class ExportPropertiesWidget : public QWidget {
 	QCheckBox *draw_colored_conductors;
 	QCheckBox *dxf_blocks;
 	QCheckBox *dxf_attributes;
+	QCheckBox *svg_small_pictures;
 	QRadioButton *export_border;
 	QRadioButton *export_elements;
 	QButtonGroup *exported_content_choices;

sources/qetgraphicsitem/diagramimageitem.cpp

@@ -167,7 +167,28 @@ void DiagramImageItem::paint(QPainter *painter, const QStyleOptionGraphicsItem *
 		return;
 	}
 
-	DarkImageRendering::paintPixmap(painter, pixmap_, m_adapt_to_dark_theme);
+		// SVG export with smaller pictures: a copy four times the size the
+		// picture is drawn at, when that is smaller than the picture. An
+		// SVG stores what it is given, so a photo shown at a tenth of its
+		// size would otherwise be written whole.
+	const QTransform world = painter -> worldTransform();
+	const qreal drawn_scale = std::sqrt(std::abs(world.determinant()));
+	const QSize small_size = (QSizeF(pixmap_.size()) * drawn_scale * 4).toSize();
+	if (diagram() && diagram() -> smallPictures() && !pixmap_.isNull()
+			&& small_size.width() < pixmap_.width()
+			&& small_size.height() < pixmap_.height()
+			&& !small_size.isEmpty())
+	{
+		const QPixmap small = pixmap_.scaled(small_size, Qt::IgnoreAspectRatio,
+											 Qt::SmoothTransformation);
+		painter -> save();
+		painter -> scale(qreal(pixmap_.width()) / small.width(),
+						 qreal(pixmap_.height()) / small.height());
+		DarkImageRendering::paintPixmap(painter, small, m_adapt_to_dark_theme);
+		painter -> restore();
+	}
+	else
+		DarkImageRendering::paintPixmap(painter, pixmap_, m_adapt_to_dark_theme);
 
 	Q_UNUSED(option); Q_UNUSED(widget);
 

tests/qttest/CMakeLists.txt

@@ -271,6 +271,15 @@ qet_add_app_test(tst_rotateselectionimage tst_rotateselectionimage.cpp)
 # it selected and records no undo step (#1414); the key goes to the view.
 qet_add_app_test(tst_imagehandleescape tst_imagehandleescape.cpp)
 
+# SVG export with smaller pictures (--svg-small-pictures, the export dialog's
+# option): a picture drawn at a tenth of its size is stored at four times
+# that, a small one whole; without the option every picture is whole.
+qet_add_app_test(tst_svgsmallpictures tst_svgsmallpictures.cpp)
+add_dependencies(tst_svgsmallpictures qelectrotech)
+target_link_libraries(tst_svgsmallpictures PRIVATE Qt::Svg)
+target_compile_definitions(tst_svgsmallpictures PRIVATE
+  "QET_TEST_BINARY_PATH=\"$<TARGET_FILE:qelectrotech>\"")
+
 # TextResizeHandles: the corner handles that change the width of a text box,
 # on a plain QGraphicsTextItem with the "textWidth" property QET texts have.
 add_executable(

tests/qttest/fixtures/svg_small_pictures.qet

@@ -0,0 +1,41 @@
+<project title="A large picture shown small" uuid="{3f6a2c91-8d47-4b5e-a0c3-91e2d7b4f600}" version="0.200.1">
+    <properties>
+        <property name="saveddate" show="1">10/2/26</property>
+        <property name="saveddate-eu" show="1">02-10-2026</property>
+        <property name="saveddate-us" show="1">2026-10-02</property>
+        <property name="savedfilename" show="1">svg_small_pictures</property>
+        <property name="savedtime" show="1">18:39</property>
+    </properties>
+    <usage enabled="true" time_spent="0"/>
+    <newdiagrams>
+        <border cols="17" colsize="60" displaycols="true" displayrows="true" rows="8" rowsize="80"/>
+        <inset author="" auto_page_num="" date="null" displayAt="bottom" filename="" folio="" indexrev="" locmach="" plant="" title="" version=""/>
+        <conductors bicolor="false" bus="" cable="" color2="#000000" condsize="1" conductor_color="" conductor_section="" dash-size="1" displaytext="1" formula="" function="" horizontal-alignment="AlignBottom" horizrotatetext="0" num="_" numsize="7" onetextperfolio="0" tension_protocol="" text_color="#000000" type="multi" vertical-alignment="AlignRight" vertirotatetext="270"/>
+        <report label="%f-%l%c"/>
+        <xrefs>
+            <xref delayprefix="" displayhas="cross" master_label="%f-%l%c" offset="0" powerprefix="" showallconfiguredslaves="false" showpowerctc="true" showterminalname="true" slave_label="(%f-%l%c)" slave_offset="0" snapto="label" switchprefix="" type="coil" xrefpos="AlignBottom"/>
+            <xref delayprefix="" displayhas="cross" master_label="%f-%l%c" offset="0" powerprefix="" showallconfiguredslaves="false" showpowerctc="true" showterminalname="true" slave_label="(%f-%l%c)" slave_offset="0" snapto="label" switchprefix="" type="commutator" xrefpos="AlignBottom"/>
+            <xref delayprefix="" displayhas="cross" master_label="%f-%l%c" offset="0" powerprefix="" showallconfiguredslaves="false" showpowerctc="true" showterminalname="true" slave_label="(%f-%l%c)" slave_offset="0" snapto="label" switchprefix="" type="plc" xrefpos="AlignBottom"/>
+            <xref delayprefix="" displayhas="cross" master_label="%f-%l%c" offset="0" powerprefix="" showallconfiguredslaves="false" showpowerctc="true" showterminalname="true" slave_label="(%f-%l%c)" slave_offset="0" snapto="label" switchprefix="" type="protection" xrefpos="AlignBottom"/>
+        </xrefs>
+        <conductors_autonums auto_break_conductors="false" current_autonum="" freeze_new_conductors="false"/>
+        <folio_autonums/>
+        <element_autonums current_autonum="" freeze_new_elements="false"/>
+        <guides/>
+    </newdiagrams>
+    <diagram author="" auto_page_num="" cols="17" colsize="60" date="null" displayAt="bottom" displaycols="true" displayrows="true" filename="" folio="" freezeNewConductor="false" freezeNewElement="false" height="660" indexrev="" locmach="" order="1" plant="" rows="8" rowsize="80" title="" uuid="{3f6a2c91-8d47-4b5e-a0c3-91e2d7b4f610}" version="0.200.1-dev">
+        <defaultconductor bicolor="false" bus="" cable="" color2="#000000" condsize="1" conductor_color="" conductor_section="" dash-size="1" displaytext="1" formula="" function="" horizontal-alignment="AlignBottom" horizrotatetext="0" num="_" numsize="7" onetextperfolio="0" tension_protocol="" text_color="#000000" type="multi" vertical-alignment="AlignRight" vertirotatetext="270"/>
+        <inputs/>
+        <images>
+            <image z="0" rotation="0" y="100" x="100" size="0.1" is_movable="1">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</image>
+            <image z="0" rotation="0" y="300" x="100" size="1" is_movable="1">iVBORw0KGgoAAAANSUhEUgAAACgAAAAeCAIAAADRv8uKAAAAP0lEQVR42u3PMQoAIAwEwRVC1F/7dFuxFoKwqS7XHNNgJSR0OMP1Pu+DQckFs2pYsWLFihUrVqxYsWLFir8Rb7mhAuQBqxaIAAAAAElFTkSuQmCC</image>
+        </images>
+    </diagram>
+    <collection>
+        <category name="import">
+            <names>
+                <name lang="en">Imported elements</name>
+            </names>
+        </category>
+    </collection>
+</project>

tests/qttest/tst_svgsmallpictures.cpp

@@ -0,0 +1,143 @@
+/*
+	Copyright 2006-2026 The QElectroTech Team
+	This file is part of QElectroTech.
+
+	QElectroTech 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.
+
+	QElectroTech is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+	GNU General Public License for more details.
+
+	You should have received a copy of the GNU General Public License
+	along with QElectroTech.  If not, see <http://www.gnu.org/licenses/>.
+*/
+#include "qetapptest.h"
+#include "qetgraphicsitem/diagramimageitem.h"
+
+#include <QBuffer>
+#include <QDomDocument>
+#include <QPicture>
+#include <QProcess>
+#include <QRegularExpression>
+#include <QSvgGenerator>
+#include <QTemporaryDir>
+
+/**
+	SVG export with "smaller pictures" (ExportProperties::svg_small_pictures,
+	--svg-small-pictures) stores each picture at four times the size it is
+	drawn at when that is smaller than the picture, and at full resolution
+	otherwise. fixtures/svg_small_pictures.qet has an 800x600 picture drawn
+	at a tenth of its size and a 40x30 one at full size.
+*/
+class tst_svgsmallpictures : public QObject
+{
+	Q_OBJECT
+
+	QString m_fixture;
+
+		/// Pixel size of each picture embedded in @p svg, smallest first
+	static QList<QSize> embeddedSizes(const QByteArray &svg)
+	{
+		static const QRegularExpression data(
+					QStringLiteral("data:image/png;base64,([A-Za-z0-9+/=\\s]+)"));
+		QList<QSize> sizes;
+		auto it = data.globalMatch(QString::fromLatin1(svg));
+		while (it.hasNext())
+			sizes << QImage::fromData(QByteArray::fromBase64(
+										  it.next().captured(1).toLatin1())).size();
+		std::sort(sizes.begin(), sizes.end(), [](const QSize &a, const QSize &b) {
+			return a.width() < b.width();
+		});
+		return sizes;
+	}
+
+	QByteArray exportWithCli(const QStringList &extra)
+	{
+		QTemporaryDir dir;
+		QProcessEnvironment env = QProcessEnvironment::systemEnvironment();
+		env.insert(QStringLiteral("QT_QPA_PLATFORM"), QStringLiteral("offscreen"));
+		QProcess proc;
+		proc.setProcessEnvironment(env);
+		proc.start(QStringLiteral(QET_TEST_BINARY_PATH),
+				   QStringList{QStringLiteral("--export-svg"), m_fixture, dir.path()} + extra);
+		if (!proc.waitForFinished(60000) || proc.exitCode() != 0)
+			return {};
+		const QStringList files = QDir(dir.path()).entryList({QStringLiteral("*.svg")});
+		QFile svg(QDir(dir.path()).filePath(files.value(0)));
+		return svg.open(QIODevice::ReadOnly) ? svg.readAll() : QByteArray();
+	}
+
+		/// As ExportDialog::generateSvg(): the folio drawn into a QPicture,
+		/// played into the SVG generator
+	static QByteArray exportLikeTheDialog(Diagram *diagram, bool small)
+	{
+		const QSize size = diagram->imageSize();
+		QPicture picture;
+		diagram->setSmallPictures(small);
+		diagram->toPaintDevice(picture, size.width(), size.height());
+		diagram->setSmallPictures(false);
+
+		QByteArray svg;
+		QBuffer buffer(&svg);
+		buffer.open(QIODevice::WriteOnly);
+		QSvgGenerator generator;
+		generator.setSize(size);
+		generator.setOutputDevice(&buffer);
+		QPainter painter(&generator);
+		picture.play(&painter);
+		painter.end();
+		return svg;
+	}
+
+private slots:
+	void initTestCase()
+	{
+		m_fixture = QFINDTESTDATA("fixtures/svg_small_pictures.qet");
+		QVERIFY2(!m_fixture.isEmpty(), "fixture project not found");
+		QVERIFY(QetAppTest::editor());
+	}
+
+	void cliFullResolutionByDefault()
+	{
+		const QByteArray svg = exportWithCli({});
+		QVERIFY2(!svg.isEmpty(), "--export-svg failed");
+		QCOMPARE(embeddedSizes(svg), (QList<QSize>{QSize(40, 30), QSize(800, 600)}));
+	}
+
+	void cliSmallPictures()
+	{
+		const QByteArray svg = exportWithCli({QStringLiteral("--svg-small-pictures")});
+		QVERIFY2(!svg.isEmpty(), "--export-svg --svg-small-pictures failed");
+			// 800 x 600 drawn at 0.1, times 4; the 40 x 30 one is kept whole
+		QCOMPARE(embeddedSizes(svg), (QList<QSize>{QSize(40, 30), QSize(320, 240)}));
+	}
+
+	void dialogSmallPicturesThenFullAgain()
+	{
+		QFile file(m_fixture);
+		QVERIFY(file.open(QIODevice::ReadOnly));
+		QDomDocument document;
+		QVERIFY(document.setContent(&file));
+		const QDomElement image_xml = document.elementsByTagName(
+					QStringLiteral("image")).at(0).toElement();
+		Diagram *diagram = QetAppTest::diagram();
+		auto *picture = new DiagramImageItem();
+		QVERIFY(picture->fromXml(image_xml));
+		diagram->addItem(picture);
+
+		QCOMPARE(embeddedSizes(exportLikeTheDialog(diagram, true)),
+				 QList<QSize>{QSize(320, 240)});
+			// The option lasts for one export only
+		QVERIFY(!diagram->smallPictures());
+		QCOMPARE(embeddedSizes(exportLikeTheDialog(diagram, false)),
+				 QList<QSize>{QSize(800, 600)});
+		delete picture;
+	}
+};
+
+QET_APP_TEST_MAIN(tst_svgsmallpictures)
+#include "tst_svgsmallpictures.moc"