diff --git a/src/calibre/gui2/tweak_book/editor/insert_resource.py b/src/calibre/gui2/tweak_book/editor/insert_resource.py
index f6905685ba..50e67eeee2 100644
--- a/src/calibre/gui2/tweak_book/editor/insert_resource.py
+++ b/src/calibre/gui2/tweak_book/editor/insert_resource.py
@@ -108,11 +108,13 @@ class ImageDelegate(QStyledItemDelegate):
             except:
                 pass
             else:
+                dpr = painter.device().devicePixelRatio()
                 cover.loadFromData(raw)
+                cover.setDevicePixelRatio(dpr)
                 if not cover.isNull():
                     scaled, width, height = fit_image(cover.width(), cover.height(), self.cover_size.width(), self.cover_size.height())
                     if scaled:
-                        cover = self.cover_cache[name] = cover.scaled(width, height, transformMode=Qt.SmoothTransformation)
+                        cover = self.cover_cache[name] = cover.scaled(int(dpr*width), int(dpr*height), transformMode=Qt.SmoothTransformation)
 
         painter.save()
         try:
@@ -121,8 +123,8 @@ class ImageDelegate(QStyledItemDelegate):
             trect = QRect(rect)
             rect.setBottom(rect.bottom() - self.title_height)
             if not cover.isNull():
-                dx = max(0, int((rect.width() - cover.width())/2.0))
-                dy = max(0, rect.height() - cover.height())
+                dx = max(0, int((rect.width() - int(cover.width()/cover.devicePixelRatio()))/2.0))
+                dy = max(0, rect.height() - int(cover.height()/cover.devicePixelRatio()))
                 rect.adjust(dx, dy, -dx, 0)
                 painter.drawPixmap(rect, cover)
             rect = trect
@@ -455,7 +457,5 @@ if __name__ == '__main__':
     from calibre.gui2.tweak_book.boss import get_container
     set_current_container(get_container(sys.argv[-1]))
 
-    d = ChooseFolder()
-    if d.exec_() == d.Accepted:
-        print (repr(d.chosen_folder))
-
+    d = InsertImage(for_browsing=True)
+    d.exec_()
diff --git a/src/calibre/gui2/tweak_book/reports.py b/src/calibre/gui2/tweak_book/reports.py
index eb2ee41eb7..5f54928ea0 100644
--- a/src/calibre/gui2/tweak_book/reports.py
+++ b/src/calibre/gui2/tweak_book/reports.py
@@ -373,25 +373,28 @@ class ImagesDelegate(QStyledItemDelegate):
         k = (th, entry.name)
         pmap = self.cache.get(k)
         if pmap is None:
-            pmap = self.cache[k] = self.pixmap(th, entry)
+            pmap = self.cache[k] = self.pixmap(th, entry, painter.device().devicePixelRatio())
         if pmap.isNull():
             bottom = option.rect.top()
         else:
             m = 2 * self.MARGIN
-            x = option.rect.left() + (option.rect.width() - m - pmap.width()) // 2
+            x = option.rect.left() + (option.rect.width() - m - int(pmap.width()/pmap.devicePixelRatio())) // 2
             painter.drawPixmap(x, option.rect.top() + self.MARGIN, pmap)
-            bottom = m + pmap.height() + option.rect.top()
+            bottom = m + int(pmap.height() / pmap.devicePixelRatio()) + option.rect.top()
         rect = QRect(option.rect.left(), bottom, option.rect.width(), option.rect.bottom() - bottom)
         if option.state & QStyle.State_Selected:
             painter.setPen(self.parent().palette().color(QPalette.HighlightedText))
         painter.drawText(rect, Qt.AlignHCenter | Qt.AlignVCenter, entry.basename)
         painter.restore()
 
-    def pixmap(self, thumbnail_height, entry):
+    def pixmap(self, thumbnail_height, entry, dpr):
         pmap = QPixmap(current_container().name_to_abspath(entry.name)) if entry.width > 0 and entry.height > 0 else QPixmap()
-        scaled, width, height = fit_image(entry.width, entry.height, thumbnail_height, thumbnail_height)
-        if scaled and not pmap.isNull():
-            pmap = pmap.scaled(width, height, transformMode=Qt.SmoothTransformation)
+        if not pmap.isNull():
+            pmap.setDevicePixelRatio(dpr)
+            scaled, width, height = fit_image(entry.width, entry.height, thumbnail_height, thumbnail_height)
+            if scaled:
+                pmap = pmap.scaled(int(dpr * width), int(dpr * height), transformMode=Qt.SmoothTransformation)
+                pmap.setDevicePixelRatio(dpr)
         return pmap