diff --git a/libosmscout-client-qt/include/osmscoutclientqt/MapRenderer.h b/libosmscout-client-qt/include/osmscoutclientqt/MapRenderer.h
index b8e87d4fa..139c09505 100644
--- a/libosmscout-client-qt/include/osmscoutclientqt/MapRenderer.h
+++ b/libosmscout-client-qt/include/osmscoutclientqt/MapRenderer.h
@@ -33,6 +33,7 @@
 #include <QSettings>
 #include <QMutex>
 #include <QPainter>
+#include <QScreen>
 
 namespace osmscout {
 
@@ -97,6 +98,7 @@ class OSMSCOUT_CLIENT_QT_API MapRenderer : public QObject {
 #endif
 
   double      mapDpi;
+  double      screenPixelRatio{1.0};
   bool        renderSea;
 
   QString     fontName;
@@ -176,6 +178,8 @@ public slots:
   virtual void onShowAltLanguageChanged(bool);
   virtual void onUnitsChanged(const QString&);
 
+  virtual void SetScreen(const QScreen*);
+
 protected:
   MapRenderer(QThread *thread,
               SettingsRef settings,
diff --git a/libosmscout-client-qt/include/osmscoutclientqt/MapWidget.h b/libosmscout-client-qt/include/osmscoutclientqt/MapWidget.h
index c45fe7f1f..5c9691164 100644
--- a/libosmscout-client-qt/include/osmscoutclientqt/MapWidget.h
+++ b/libosmscout-client-qt/include/osmscoutclientqt/MapWidget.h
@@ -188,6 +188,7 @@ class OSMSCOUT_CLIENT_QT_API MapWidget : public QQuickPaintedItem
   void styleErrorsChanged();
   void databaseLoaded(osmscout::GeoBox);
   void renderingTypeChanged(QString type);
+  void screenChanged(QScreen*);
 
 public slots:
   void changeView(const MapView &view);
@@ -309,6 +310,8 @@ private slots:
 
   void onResize();
 
+  void onWindowChanged(QQuickWindow *window);
+
 private:
   void setupInputHandler(InputHandler *newGesture);
 
@@ -320,6 +323,8 @@ private slots:
    */
   osmscout::Magnification magnificationByDimension(const Distance &dimension);
 
+  void setupRenderer();
+
 public:
   MapWidget(QQuickItem* parent = nullptr);
   ~MapWidget() override;
diff --git a/libosmscout-client-qt/include/osmscoutclientqt/TileCache.h b/libosmscout-client-qt/include/osmscoutclientqt/TileCache.h
index d33e6d1c2..5589fb793 100644
--- a/libosmscout-client-qt/include/osmscoutclientqt/TileCache.h
+++ b/libosmscout-client-qt/include/osmscoutclientqt/TileCache.h
@@ -70,7 +70,7 @@ QDebug& operator<<(QDebug &out, const TileCacheKey &key);
 struct TileCacheVal
 {
   QElapsedTimer lastAccess;
-  QPixmap image;
+  QImage image;
   size_t epoch;
 };
 
@@ -141,7 +141,7 @@ class OSMSCOUT_CLIENT_QT_API TileCache : public QObject
    * @return true if there was such request
    */
   bool removeRequest(uint32_t zoomLevel, uint32_t x, uint32_t y);
-  void put(uint32_t zoomLevel, uint32_t x, uint32_t y, QImage image, size_t epoch = 0);
+  void put(uint32_t zoomLevel, uint32_t x, uint32_t y, const QImage &image, size_t epoch = 0);
 
   void cleanupCache();
 
diff --git a/libosmscout-client-qt/src/osmscoutclientqt/MapRenderer.cpp b/libosmscout-client-qt/src/osmscoutclientqt/MapRenderer.cpp
index 7c8c12136..feec5b3af 100644
--- a/libosmscout-client-qt/src/osmscoutclientqt/MapRenderer.cpp
+++ b/libosmscout-client-qt/src/osmscoutclientqt/MapRenderer.cpp
@@ -157,6 +157,23 @@ void MapRenderer::onUnitsChanged(const QString& units)
   emit Redraw();
 }
 
+void MapRenderer::SetScreen(const QScreen *screen)
+{
+  bool changed=false;
+  {
+    QMutexLocker locker(&lock);
+    if (this->screenPixelRatio != screen->devicePixelRatio()) {
+      this->screenPixelRatio = screen->devicePixelRatio();
+      log.Debug() << "Screen pixel ratio: " << this->screenPixelRatio;
+      changed = true;
+    }
+  }
+  if (changed) {
+    InvalidateVisualCache();
+    emit Redraw();
+  }
+}
+
 void MapRenderer::addOverlayObject(int id, const OverlayObjectRef& obj)
 {
   {
diff --git a/libosmscout-client-qt/src/osmscoutclientqt/MapWidget.cpp b/libosmscout-client-qt/src/osmscoutclientqt/MapWidget.cpp
index 7139ad7f3..2c9b1fadf 100644
--- a/libosmscout-client-qt/src/osmscoutclientqt/MapWidget.cpp
+++ b/libosmscout-client-qt/src/osmscoutclientqt/MapWidget.cpp
@@ -27,6 +27,7 @@
 #include <QtSvg/QSvgRenderer>
 #include <QtGlobal>
 #include <QQuickWindow>
+#include <QGuiApplication>
 
 namespace osmscout {
 
@@ -45,7 +46,8 @@ MapWidget::MapWidget(QQuickItem* parent)
     setAcceptTouchEvents(true);
 #endif
 
-    renderer = OSMScoutQt::GetInstance().MakeMapRenderer(renderingType);
+    setupRenderer();
+
     auto settings=OSMScoutQt::GetInstance().GetSettings();
 
     DBThreadRef dbThread = OSMScoutQt::GetInstance().GetDBThread();
@@ -57,9 +59,6 @@ MapWidget::MapWidget(QQuickItem* parent)
 
     tapRecognizer.setPhysicalDpi(dbThread->GetPhysicalDpi());
 
-    connect(renderer, &MapRenderer::Redraw,
-            this, &MapWidget::redraw);
-
     connect(&tapRecognizer, &TapRecognizer::tap,        this, &MapWidget::onTap);
     connect(&tapRecognizer, &TapRecognizer::doubleTap,  this, &MapWidget::onDoubleTap);
     connect(&tapRecognizer, &TapRecognizer::longTap,    this, &MapWidget::onLongTap);
@@ -68,6 +67,7 @@ MapWidget::MapWidget(QQuickItem* parent)
 
     connect(this, &QQuickItem::widthChanged, this, &MapWidget::onResize);
     connect(this, &QQuickItem::heightChanged, this, &MapWidget::onResize);
+    connect(this, &QQuickItem::windowChanged, this, &MapWidget::onWindowChanged);
 
     connect(&iconAnimation, &IconAnimation::update, this, &MapWidget::redraw);
 
@@ -100,6 +100,38 @@ MapWidget::~MapWidget()
     }
 }
 
+void MapWidget::setupRenderer()
+{
+    if (renderer) {
+      renderer->deleteLater();
+    }
+
+    renderer = OSMScoutQt::GetInstance().MakeMapRenderer(renderingType);
+
+    connect(renderer, &MapRenderer::Redraw,
+            this, &MapWidget::redraw);
+
+    connect(this, &MapWidget::screenChanged,
+            renderer, &MapRenderer::SetScreen,
+            Qt::QueuedConnection);
+
+    QQuickWindow *window = this->window();
+    if (window) {
+      emit screenChanged(window->screen());
+    } else {
+      emit screenChanged(QGuiApplication::primaryScreen());
+    }
+}
+
+void MapWidget::onWindowChanged(QQuickWindow *window)
+{
+    if (window) {
+      emit screenChanged(window->screen());
+      connect(window, &QWindow::screenChanged,
+              this, &MapWidget::screenChanged);
+    }
+}
+
 void MapWidget::translateToTouch(QMouseEvent* event, Qt::TouchPointStates states)
 {
     assert(event);
@@ -1024,14 +1056,13 @@ void MapWidget::SetRenderingType(QString strType)
     renderingType=type;
 
     std::map<int,OverlayObjectRef> overlayWays = renderer->getOverlayObjects();
-    renderer->deleteLater();
 
-    renderer = OSMScoutQt::GetInstance().MakeMapRenderer(renderingType);
+    setupRenderer();
+
     for (auto &p:overlayWays){
       renderer->addOverlayObject(p.first, p.second);
     }
-    connect(renderer, &MapRenderer::Redraw,
-            this, &MapWidget::redraw);
+
     emit renderingTypeChanged(GetRenderingType());
   }
 }
diff --git a/libosmscout-client-qt/src/osmscoutclientqt/OSMScoutQt.cpp b/libosmscout-client-qt/src/osmscoutclientqt/OSMScoutQt.cpp
index e0d710945..70dccf4c3 100644
--- a/libosmscout-client-qt/src/osmscoutclientqt/OSMScoutQt.cpp
+++ b/libosmscout-client-qt/src/osmscoutclientqt/OSMScoutQt.cpp
@@ -97,8 +97,8 @@ bool OSMScoutQtBuilder::Init()
    *   130 - PC (24" FullHD)
    *   100 - Qt default (reported by SailfishOS < 2.0.1)
    */
-  QScreen *srn=QGuiApplication::screens().at(0);
-  double physicalDpi = (double)srn->physicalDotsPerInch();
+  QScreen *srn=QGuiApplication::primaryScreen();
+  double physicalDpi = srn ? (double)srn->physicalDotsPerInch() : 100;
 
   QLocale locale;
   QString defaultUnits;
diff --git a/libosmscout-client-qt/src/osmscoutclientqt/PlaneMapRenderer.cpp b/libosmscout-client-qt/src/osmscoutclientqt/PlaneMapRenderer.cpp
index 705d28426..8a82f8cad 100644
--- a/libosmscout-client-qt/src/osmscoutclientqt/PlaneMapRenderer.cpp
+++ b/libosmscout-client-qt/src/osmscoutclientqt/PlaneMapRenderer.cpp
@@ -326,7 +326,7 @@ void PlaneMapRenderer::DrawMap()
 
       currentImage=new QImage(QSize(currentWidth,
                                     currentHeight),
-                              QImage::Format_RGB32);
+                              QImage::Format_RGBA8888_Premultiplied);
     }
 
     osmscout::MapParameter       drawParameter;
diff --git a/libosmscout-client-qt/src/osmscoutclientqt/TileCache.cpp b/libosmscout-client-qt/src/osmscoutclientqt/TileCache.cpp
index f3bce8ecf..1fcb69d3b 100644
--- a/libosmscout-client-qt/src/osmscoutclientqt/TileCache.cpp
+++ b/libosmscout-client-qt/src/osmscoutclientqt/TileCache.cpp
@@ -174,7 +174,7 @@ TileCacheVal TileCache::get(uint32_t zoomLevel, uint32_t x, uint32_t y)
     TileCacheKey key = {zoomLevel, x, y};
     if (!tiles.contains(key)){
         qWarning() << this << "No tile in cache for key " << key;
-        return {QElapsedTimer(), QPixmap(), epoch}; // throw std::underflow_error ?
+        return {QElapsedTimer(), QImage(), epoch}; // throw std::underflow_error ?
     }
     TileCacheVal val = tiles.value(key);
     val.lastAccess.start();
@@ -193,14 +193,13 @@ bool TileCache::removeRequest(uint32_t zoomLevel, uint32_t x, uint32_t y)
     return requests.remove(key) > 0;
 }
 
-void TileCache::put(uint32_t zoomLevel, uint32_t x, uint32_t y, QImage image, size_t epoch)
+void TileCache::put(uint32_t zoomLevel, uint32_t x, uint32_t y, const QImage &image, size_t epoch)
 {
-    QPixmap pixmap = QPixmap::fromImage(image);
     removeRequest(zoomLevel, x, y);
     TileCacheKey key = {zoomLevel, x, y};
     QElapsedTimer now;
     now.start();
-    TileCacheVal val = {now, pixmap, epoch};
+    TileCacheVal val = {now, image, epoch};
 
 #ifdef DEBUG_TILE_CACHE
     qDebug() << this << "inserting tile" << key;
diff --git a/libosmscout-client-qt/src/osmscoutclientqt/TiledMapRenderer.cpp b/libosmscout-client-qt/src/osmscoutclientqt/TiledMapRenderer.cpp
index 4b66d6b08..66da5ee61 100644
--- a/libosmscout-client-qt/src/osmscoutclientqt/TiledMapRenderer.cpp
+++ b/libosmscout-client-qt/src/osmscoutclientqt/TiledMapRenderer.cpp
@@ -28,6 +28,7 @@
 
 #include <QGuiApplication>
 #include <QScreen>
+#include <QtCore>
 
 namespace osmscout {
 TiledMapRenderer::TiledMapRenderer(QThread *thread,
@@ -418,11 +419,20 @@ void TiledMapRenderer::onLoadJobFinished(QMap<QString,QMap<osmscout::TileKey,osm
             (double)loadXFrom + (double)width/2.0,
             (double)loadYFrom + (double)height/2.0);
 
-    double osmTileDimension = (double)OSMTile::osmTileOriginalWidth() * (mapDpi / OSMTile::tileDPI() ); // pixels
+    // For HiDPI screens (screenPixelRatio > 1) tiles as up-scaled before displaying. When there is ratio 2.0, 100px on Qt canvas
+    // is displayed as 200px on the screen. To provide best results on HiDPI screen, we upscale tiles by this pixel ratio.
+    double finalDpi = mapDpi * this->screenPixelRatio;
 
-    QImage canvas((double)width * osmTileDimension,
-                  (double)height * osmTileDimension,
-                  QImage::Format_ARGB32_Premultiplied); // TODO: verify best format with profiler (callgrind)
+    uint32_t tileDimension = double(OSMTile::osmTileOriginalWidth()) * (finalDpi / OSMTile::tileDPI()); // pixels
+
+    // older/mobile OpenGL (without GL_ARB_texture_non_power_of_two) requires textures with size of power of two
+    // we should provide tiles with required size to avoid scaling in QOpenGLTextureCache::bindTexture
+    tileDimension = qNextPowerOfTwo(tileDimension - 1);
+    finalDpi = (double(tileDimension) / double(OSMTile::osmTileOriginalWidth())) * OSMTile::tileDPI();
+
+    QImage canvas(width * tileDimension,
+                  height * tileDimension,
+                  QImage::Format_RGBA8888_Premultiplied);
 
     QColor transparent = QColor::fromRgbF(1, 1, 1, 0.0);
     canvas.fill(transparent);
@@ -468,7 +478,7 @@ void TiledMapRenderer::onLoadJobFinished(QMap<QString,QMap<osmscout::TileKey,osm
     osmscout::MercatorProjection projection;
     osmscout::Magnification magnification(loadZ);
 
-    projection.Set(tileVisualCenter, /* angle */ 0, magnification, mapDpi,
+    projection.Set(tileVisualCenter, /* angle */ 0, magnification, finalDpi,
                    canvas.width(), canvas.height());
     projection.SetLinearInterpolationUsage(loadZ.Get() >= 10);
 
@@ -519,9 +529,9 @@ void TiledMapRenderer::onLoadJobFinished(QMap<QString,QMap<osmscout::TileKey,osm
                 for (uint32_t x = loadXFrom; x <= loadXTo; ++x){
 
                     QImage tile = canvas.copy(
-                            (double)(x - loadXFrom) * osmTileDimension,
-                            (double)(y - loadYFrom) * osmTileDimension,
-                            osmTileDimension, osmTileDimension
+                            (x - loadXFrom) * tileDimension,
+                            (y - loadYFrom) * tileDimension,
+                            tileDimension, tileDimension
                             );
 
                     offlineTileCache.put(loadZ.Get(), x, y, tile, loadEpoch);
diff --git a/libosmscout-client-qt/src/osmscoutclientqt/TiledRenderingHelper.cpp b/libosmscout-client-qt/src/osmscoutclientqt/TiledRenderingHelper.cpp
index f8dd8776d..b53ecfb57 100644
--- a/libosmscout-client-qt/src/osmscoutclientqt/TiledRenderingHelper.cpp
+++ b/libosmscout-client-qt/src/osmscoutclientqt/TiledRenderingHelper.cpp
@@ -65,16 +65,10 @@ bool TiledRenderingHelper::RenderTiles(QPainter &painter,
     }
   }
 
-  // enable subpixel rendering so that magnification up to 2x remains
-  // as smooth as possible
-  static constexpr double pitchFactor = 1.5;
-  // the magnification level is adjusted taking into account the pixel
-  // ratio of the request and the fixed dpi of the OSM tile
   projection.Set(request.coord,
                  0,
-                 Magnification(request.magnification.GetMagnification()
-                               * pitchFactor * request.dpi / OSMTile::tileDPI()),
-                 OSMTile::tileDPI() / pitchFactor,
+                 request.magnification,
+                 request.dpi,
                  width,
                  height);
 
@@ -224,8 +218,7 @@ bool TiledRenderingHelper::lookupAndDrawTile(TileCache& tileCache, QPainter& pai
         QRectF imageViewport(imageWidth * lookupTileViewport.x(), imageHeight * lookupTileViewport.y(),
                              imageWidth * lookupTileViewport.width(), imageHeight * lookupTileViewport.height() );
 
-        // TODO: support map rotation
-        painter.drawPixmap(QRectF(x, y, renderTileWidth+overlap, renderTileHeight+overlap), val.image, imageViewport);
+        painter.drawImage(QRectF(x, y, renderTileWidth+overlap, renderTileHeight+overlap), val.image, imageViewport);
       }
       lookupTileFound = true;
       if (lookupTileZoom == zoomLevel && val.epoch == tileCache.getEpoch()) {
@@ -300,7 +293,7 @@ void TiledRenderingHelper::lookupAndDrawBottomTileRecursive(TileCache& tileCache
         if (!val.image.isNull()){
           double imageWidth = val.image.width();
           double imageHeight = val.image.height();
-          painter.drawPixmap(
+          painter.drawImage(
               QRectF(x + tx * (renderTileWidth/tileCnt), y + ty * (renderTileHeight/tileCnt), renderTileWidth/tileCnt + overlap, renderTileHeight/tileCnt + overlap),
               val.image,
               QRectF(0.0, 0.0, imageWidth, imageHeight));