diff --git a/src/map/IMG/gmapdata.cpp b/src/map/IMG/gmapdata.cpp
index 58b141f0..1e15c1e2 100644
--- a/src/map/IMG/gmapdata.cpp
+++ b/src/map/IMG/gmapdata.cpp
@@ -92,7 +92,7 @@ bool GMAPData::loadTile(const QDir &dir)
 		}
 	}
 
-	if (!tile->init()) {
+	if (!tile->init(0)) {
 		qWarning("%s: Invalid map tile", qPrintable(dir.path()));
 		delete tile;
 		return false;
diff --git a/src/map/IMG/imgdata.cpp b/src/map/IMG/imgdata.cpp
index a180b570..41ea1a4e 100644
--- a/src/map/IMG/imgdata.cpp
+++ b/src/map/IMG/imgdata.cpp
@@ -29,11 +29,11 @@ static SubFile::Type tileType(const char str[3])
 		return SubFile::Unknown;
 }
 
-bool IMGData::readSubFileBlocks(QFile &file, quint64 offset, SubFile *subFile)
+bool IMGData::readSubFileBlocks(QFile *file, quint64 offset, SubFile *subFile)
 {
 	quint16 block;
 
-	if (!file.seek(offset + 0x20))
+	if (!file->seek(offset + 0x20))
 		return false;
 	for (int i = 0; i < 240; i++) {
 		if (!readValue(file, block))
@@ -46,11 +46,11 @@ bool IMGData::readSubFileBlocks(QFile &file, quint64 offset, SubFile *subFile)
 	return true;
 }
 
-bool IMGData::readIMGHeader(QFile &file)
+bool IMGData::readIMGHeader(QFile *file)
 {
 	char signature[7], identifier[7];
-	if (!(file.read((char*)&_key, 1) && file.seek(0x10)
-	  && read(file, signature, sizeof(signature)) && file.seek(0x41)
+	if (!(file->read((char*)&_key, 1) && file->seek(0x10)
+	  && read(file, signature, sizeof(signature)) && file->seek(0x41)
 	  && read(file, identifier, sizeof(identifier)))
 	  || memcmp(signature, "DSKIMG", sizeof(signature))
 	  || memcmp(identifier, "GARMIN", sizeof(identifier))) {
@@ -60,8 +60,8 @@ bool IMGData::readIMGHeader(QFile &file)
 
 	char d1[20], d2[31];
 	quint8 e1, e2;
-	if (!(file.seek(0x49) && read(file, d1, sizeof(d1)) && file.seek(0x61)
-	  && readValue(file, e1) && readValue(file, e2) && file.seek(0x65)
+	if (!(file->seek(0x49) && read(file, d1, sizeof(d1)) && file->seek(0x61)
+	  && readValue(file, e1) && readValue(file, e2) && file->seek(0x65)
 	  && read(file, d2, sizeof(d2)))) {
 		_errorString = "Error reading IMG header";
 		return false;
@@ -74,7 +74,7 @@ bool IMGData::readIMGHeader(QFile &file)
 	return true;
 }
 
-bool IMGData::readFAT(QFile &file, TileMap &tileMap)
+bool IMGData::readFAT(QFile *file, TileMap &tileMap)
 {
 	QByteArray typFile;
 	quint8 flag;
@@ -82,7 +82,7 @@ bool IMGData::readFAT(QFile &file, TileMap &tileMap)
 
 	// Skip unused FAT blocks if any
 	while (true) {
-		if (!(file.seek(offset) && readValue(file, flag)))
+		if (!(file->seek(offset) && readValue(file, flag)))
 			return false;
 		if (flag)
 			break;
@@ -93,14 +93,14 @@ bool IMGData::readFAT(QFile &file, TileMap &tileMap)
 	char name[8], type[3];
 	quint32 size;
 	quint16 part;
-	if (!(file.seek(offset + 12) && readValue(file, size)))
+	if (!(file->seek(offset + 12) && readValue(file, size)))
 		return false;
 	offset += 512;
 	int cnt = (size - offset) / 512;
 
 	// Read FAT blocks describing the IMG sub-files
 	for (int i = 0; i < cnt; i++) {
-		if (!(file.seek(offset) && readValue(file, flag)
+		if (!(file->seek(offset) && readValue(file, flag)
 		  && read(file, name, sizeof(name))
 		  && read(file, type, sizeof(type)) && readValue(file, size)
 		  && readValue(file, part)))
@@ -140,13 +140,13 @@ bool IMGData::readFAT(QFile &file, TileMap &tileMap)
 	return true;
 }
 
-bool IMGData::createTileTree(const TileMap &tileMap)
+bool IMGData::createTileTree(QFile *file, const TileMap &tileMap)
 {
 	for (TileMap::const_iterator it = tileMap.constBegin();
 	  it != tileMap.constEnd(); ++it) {
 		VectorTile *tile = it.value();
 
-		if (!tile->init()) {
+		if (!tile->init(file)) {
 			qWarning("%s: %s: Invalid map tile", qPrintable(_fileName),
 			  qPrintable(it.key()));
 			delete tile;
@@ -177,14 +177,14 @@ IMGData::IMGData(const QString &fileName) : MapData(fileName)
 		return;
 	}
 
-	if (!readIMGHeader(file))
+	if (!readIMGHeader(&file))
 		return;
-	if (!readFAT(file, tileMap)) {
+	if (!readFAT(&file, tileMap)) {
 		_errorString = "Error reading FAT data";
 		qDeleteAll(tileMap);
 		return;
 	}
-	if (!createTileTree(tileMap)) {
+	if (!createTileTree(&file, tileMap)) {
 		_errorString = "No usable map tile found";
 		return;
 	}
@@ -194,16 +194,16 @@ IMGData::IMGData(const QString &fileName) : MapData(fileName)
 	_valid = true;
 }
 
-qint64 IMGData::read(QFile &file, char *data, qint64 maxSize) const
+qint64 IMGData::read(QFile *file, char *data, qint64 maxSize) const
 {
-	qint64 ret = file.read(data, maxSize);
+	qint64 ret = file->read(data, maxSize);
 	if (_key)
 		for (int i = 0; i < ret; i++)
 			data[i] ^= _key;
 	return ret;
 }
 
-template<class T> bool IMGData::readValue(QFile &file, T &val) const
+template<class T> bool IMGData::readValue(QFile *file, T &val) const
 {
 	T data;
 
@@ -215,9 +215,9 @@ template<class T> bool IMGData::readValue(QFile &file, T &val) const
 	return true;
 }
 
-bool IMGData::readBlock(QFile &file, int blockNum, char *data) const
+bool IMGData::readBlock(QFile *file, int blockNum, char *data) const
 {
-	if (!file.seek((quint64)blockNum << _blockBits))
+	if (!file->seek((quint64)blockNum << _blockBits))
 		return false;
 	if (read(file, data, 1ULL<<_blockBits) < (qint64)(1ULL<<_blockBits))
 		return false;
diff --git a/src/map/IMG/imgdata.h b/src/map/IMG/imgdata.h
index 5c651b6c..28826d4d 100644
--- a/src/map/IMG/imgdata.h
+++ b/src/map/IMG/imgdata.h
@@ -13,17 +13,17 @@ public:
 	IMGData(const QString &fileName);
 
 	unsigned blockBits() const {return _blockBits;}
-	bool readBlock(QFile &file, int blockNum, char *data) const;
+	bool readBlock(QFile *file, int blockNum, char *data) const;
 
 private:
 	typedef QMap<QByteArray, VectorTile*> TileMap;
 
-	qint64 read(QFile &file, char *data, qint64 maxSize) const;
-	template<class T> bool readValue(QFile &file, T &val) const;
-	bool readSubFileBlocks(QFile &file, quint64 offset, SubFile *subFile);
-	bool readFAT(QFile &file, TileMap &tileMap);
-	bool readIMGHeader(QFile &file);
-	bool createTileTree(const TileMap &tileMap);
+	qint64 read(QFile *file, char *data, qint64 maxSize) const;
+	template<class T> bool readValue(QFile *file, T &val) const;
+	bool readSubFileBlocks(QFile *file, quint64 offset, SubFile *subFile);
+	bool readFAT(QFile *file, TileMap &tileMap);
+	bool readIMGHeader(QFile *file);
+	bool createTileTree(QFile *file, const TileMap &tileMap);
 
 	quint8 _key;
 	unsigned _blockBits;
diff --git a/src/map/IMG/mapdata.cpp b/src/map/IMG/mapdata.cpp
index 53ae01a0..68c031a5 100644
--- a/src/map/IMG/mapdata.cpp
+++ b/src/map/IMG/mapdata.cpp
@@ -13,7 +13,7 @@ using namespace IMG;
 bool MapData::polyCb(VectorTile *tile, void *context)
 {
 	PolyCTX *ctx = (PolyCTX*)context;
-	tile->polys(ctx->rect, ctx->zoom, ctx->polygons, ctx->lines,
+	tile->polys(ctx->file, ctx->rect, ctx->zoom, ctx->polygons, ctx->lines,
 	  ctx->cache, ctx->lock);
 	return true;
 }
@@ -21,14 +21,16 @@ bool MapData::polyCb(VectorTile *tile, void *context)
 bool MapData::pointCb(VectorTile *tile, void *context)
 {
 	PointCTX *ctx = (PointCTX*)context;
-	tile->points(ctx->rect, ctx->zoom, ctx->points, ctx->cache, ctx->lock);
+	tile->points(ctx->file, ctx->rect, ctx->zoom, ctx->points, ctx->cache,
+	  ctx->lock);
 	return true;
 }
 
 bool MapData::elevationCb(VectorTile *tile, void *context)
 {
 	ElevationCTX *ctx = (ElevationCTX*)context;
-	tile->elevations(ctx->rect, ctx->zoom, ctx->elevations, ctx->cache, ctx->lock);
+	tile->elevations(ctx->file, ctx->rect, ctx->zoom, ctx->elevations,
+	  ctx->cache, ctx->lock);
 	return true;
 }
 
@@ -50,10 +52,10 @@ MapData::~MapData()
 	delete _style;
 }
 
-void MapData::polys(const RectC &rect, int bits, QList<Poly> *polygons,
-  QList<Poly> *lines)
+void MapData::polys(QFile *file, const RectC &rect, int bits,
+  QList<Poly> *polygons, QList<Poly> *lines)
 {
-	PolyCTX ctx(rect, zoom(bits), polygons, lines, &_polyCache, &_lock);
+	PolyCTX ctx(file, rect, zoom(bits), polygons, lines, &_polyCache, &_lock);
 	double min[2], max[2];
 
 	min[0] = rect.left();
@@ -64,9 +66,10 @@ void MapData::polys(const RectC &rect, int bits, QList<Poly> *polygons,
 	_tileTree.Search(min, max, polyCb, &ctx);
 }
 
-void MapData::points(const RectC &rect, int bits, QList<Point> *points)
+void MapData::points(QFile *file, const RectC &rect, int bits,
+  QList<Point> *points)
 {
-	PointCTX ctx(rect, zoom(bits), points, &_pointCache, &_lock);
+	PointCTX ctx(file, rect, zoom(bits), points, &_pointCache, &_lock);
 	double min[2], max[2];
 
 	min[0] = rect.left();
@@ -77,9 +80,10 @@ void MapData::points(const RectC &rect, int bits, QList<Point> *points)
 	_tileTree.Search(min, max, pointCb, &ctx);
 }
 
-void MapData::elevations(const RectC &rect, int bits, QList<Elevation> *elevations)
+void MapData::elevations(QFile *file, const RectC &rect, int bits,
+  QList<Elevation> *elevations)
 {
-	ElevationCTX ctx(rect, zoom(bits), elevations, &_demCache, &_demLock);
+	ElevationCTX ctx(file, rect, zoom(bits), elevations, &_demCache, &_demLock);
 	double min[2], max[2];
 
 	min[0] = rect.left();
@@ -95,14 +99,14 @@ void MapData::load(qreal ratio)
 	Q_ASSERT(!_style);
 
 	if (_typ)
-		_style = new Style(ratio, _typ);
+		_style = new Style(0, ratio, _typ);
 	else {
 		QString typFile(ProgramPaths::typFile());
 		if (QFileInfo::exists(typFile)) {
 			SubFile typ(&typFile);
-			_style = new Style(ratio, &typ);
+			_style = new Style(0, ratio, &typ);
 		} else
-			_style = new Style(ratio);
+			_style = new Style(0, ratio);
 	}
 }
 
diff --git a/src/map/IMG/mapdata.h b/src/map/IMG/mapdata.h
index 4de46e76..a1cd688f 100644
--- a/src/map/IMG/mapdata.h
+++ b/src/map/IMG/mapdata.h
@@ -5,6 +5,7 @@
 #include <QPointF>
 #include <QCache>
 #include <QMutex>
+#include <QFile>
 #include <QDebug>
 #include "common/rectc.h"
 #include "common/rtree.h"
@@ -77,10 +78,11 @@ public:
 	const RectC &bounds() const {return _bounds;}
 	const Range &zooms() const {return _zoomLevels;}
 	const Style *style() const {return _style;}
-	void polys(const RectC &rect, int bits, QList<Poly> *polygons,
+	void polys(QFile *file, const RectC &rect, int bits, QList<Poly> *polygons,
 	  QList<Poly> *lines);
-	void points(const RectC &rect, int bits, QList<Point> *points);
-	void elevations(const RectC &rect, int bits, QList<Elevation> *elevations);
+	void points(QFile *file, const RectC &rect, int bits, QList<Point> *points);
+	void elevations(QFile *file, const RectC &rect, int bits,
+	  QList<Elevation> *elevations);
 
 	void load(qreal ratio);
 	void clear();
@@ -122,12 +124,13 @@ private:
 
 	struct PolyCTX
 	{
-		PolyCTX(const RectC &rect, const Zoom &zoom,
+		PolyCTX(QFile *file, const RectC &rect, const Zoom &zoom,
 		  QList<MapData::Poly> *polygons, QList<MapData::Poly> *lines,
 		  PolyCache *cache, QMutex *lock)
-		  : rect(rect), zoom(zoom), polygons(polygons), lines(lines),
-		  cache(cache), lock(lock) {}
+		  : file(file), rect(rect), zoom(zoom), polygons(polygons),
+		  lines(lines), cache(cache), lock(lock) {}
 
+		QFile *file;
 		const RectC &rect;
 		const Zoom &zoom;
 		QList<MapData::Poly> *polygons;
@@ -138,10 +141,12 @@ private:
 
 	struct PointCTX
 	{
-		PointCTX(const RectC &rect, const Zoom &zoom,
+		PointCTX(QFile *file, const RectC &rect, const Zoom &zoom,
 		  QList<MapData::Point> *points, PointCache *cache, QMutex *lock)
-		  : rect(rect), zoom(zoom), points(points), cache(cache), lock(lock) {}
+		  : file(file), rect(rect), zoom(zoom), points(points), cache(cache),
+		  lock(lock) {}
 
+		QFile *file;
 		const RectC &rect;
 		const Zoom &zoom;
 		QList<MapData::Point> *points;
@@ -151,11 +156,12 @@ private:
 
 	struct ElevationCTX
 	{
-		ElevationCTX(const RectC &rect, const Zoom &zoom,
+		ElevationCTX(QFile *file, const RectC &rect, const Zoom &zoom,
 		  QList<Elevation> *elevations, ElevationCache *cache, QMutex *lock)
-		  : rect(rect), zoom(zoom), elevations(elevations), cache(cache),
-		  lock(lock) {}
+		  : file(file), rect(rect), zoom(zoom), elevations(elevations),
+		  cache(cache), lock(lock) {}
 
+		QFile *file;
 		const RectC &rect;
 		const Zoom &zoom;
 		QList<Elevation> *elevations;
diff --git a/src/map/IMG/rastertile.cpp b/src/map/IMG/rastertile.cpp
index 7425cada..dd4c5b20 100644
--- a/src/map/IMG/rastertile.cpp
+++ b/src/map/IMG/rastertile.cpp
@@ -152,7 +152,7 @@ void RasterTile::drawPolygons(QPainter *painter,
 				bool insert = false;
 				SubFile::Handle *hdl = hc.object(poly.raster.lbl());
 				if (!hdl) {
-					hdl = new SubFile::Handle(poly.raster.lbl());
+					hdl = new SubFile::Handle(_file, poly.raster.lbl());
 					insert = true;
 				}
 				QPixmap pm(poly.raster.lbl()->image(*hdl, poly.raster.id()));
@@ -443,11 +443,16 @@ void RasterTile::fetchData(QList<MapData::Poly> &polygons,
 {
 	QPoint ttl(_rect.topLeft());
 
+	if (dynamic_cast<IMGData*>(_data)) {
+		_file = new QFile(_data->fileName());
+		_file->open(QIODevice::ReadOnly | QIODevice::Unbuffered);
+	}
+
 	QRectF polyRect(ttl, QPointF(ttl.x() + _rect.width(), ttl.y()
 	  + _rect.height()));
 	RectD polyRectD(_transform.img2proj(polyRect.topLeft()),
 	  _transform.img2proj(polyRect.bottomRight()));
-	_data->polys(polyRectD.toRectC(_proj, 20), _zoom,
+	_data->polys(_file, polyRectD.toRectC(_proj, 20), _zoom,
 	  &polygons, _vectors ? &lines : 0);
 
 	if (_vectors) {
@@ -456,7 +461,7 @@ void RasterTile::fetchData(QList<MapData::Poly> &polygons,
 		  + TEXT_EXTENT));
 		RectD pointRectD(_transform.img2proj(pointRect.topLeft()),
 		  _transform.img2proj(pointRect.bottomRight()));
-		_data->points(pointRectD.toRectC(_proj, 20), _zoom, &points);
+		_data->points(_file, pointRectD.toRectC(_proj, 20), _zoom, &points);
 	}
 }
 
@@ -481,7 +486,7 @@ MatrixD RasterTile::elevation(int extend) const
 		// Extra margin for always including the next DEM tile on the map tile
 		// edges (the DEM tile resolution is usally 0.5-15% of the map tile)
 		double factor = 6 - (_zoom - 24) * 1.7;
-		_data->elevations(rect.adjusted(0, 0, rect.width() / factor,
+		_data->elevations(_file, rect.adjusted(0, 0, rect.width() / factor,
 		  -rect.height() / factor), _zoom, &tiles);
 
 		DEMTree tree(tiles);
diff --git a/src/map/IMG/rastertile.h b/src/map/IMG/rastertile.h
index 96871739..c394a841 100644
--- a/src/map/IMG/rastertile.h
+++ b/src/map/IMG/rastertile.h
@@ -22,7 +22,8 @@ public:
 	  bool hillShading, bool rasters, bool vectors)
 		: _proj(proj), _transform(transform), _data(data), _zoom(zoom),
 		_rect(rect), _ratio(ratio), _key(key), _hillShading(hillShading),
-		_rasters(rasters), _vectors(vectors) {}
+		_rasters(rasters), _vectors(vectors), _file(0) {}
+	~RasterTile() {delete _file;}
 
 	const QString &key() const {return _key;}
 	QPoint xy() const {return _rect.topLeft();}
@@ -88,6 +89,7 @@ private:
 	QPixmap _pixmap;
 	bool _hillShading;
 	bool _rasters, _vectors;
+	QFile *_file;
 };
 
 }
diff --git a/src/map/IMG/style.cpp b/src/map/IMG/style.cpp
index 372acb8a..6e56e81a 100644
--- a/src/map/IMG/style.cpp
+++ b/src/map/IMG/style.cpp
@@ -1268,50 +1268,50 @@ bool Style::parseDrawOrder(SubFile *file, SubFile::Handle &hdl,
 	return true;
 }
 
-bool Style::parseTYPFile(SubFile *file)
+bool Style::parseTYPFile(QFile *file, SubFile *typ)
 {
-	SubFile::Handle hdl(file);
+	SubFile::Handle hdl(file, typ);
 	Section points, lines, polygons, order;
 	quint16 tmp16, codepage;
 
-	if (!(file->seek(hdl, 0x15) && file->readUInt16(hdl, codepage)
-	  && file->readUInt32(hdl, points.offset)
-	  && file->readUInt32(hdl, points.size)
-	  && file->readUInt32(hdl, lines.offset)
-	  && file->readUInt32(hdl, lines.size)
-	  && file->readUInt32(hdl, polygons.offset)
-	  && file->readUInt32(hdl, polygons.size)))
+	if (!(typ->seek(hdl, 0x15) && typ->readUInt16(hdl, codepage)
+	  && typ->readUInt32(hdl, points.offset)
+	  && typ->readUInt32(hdl, points.size)
+	  && typ->readUInt32(hdl, lines.offset)
+	  && typ->readUInt32(hdl, lines.size)
+	  && typ->readUInt32(hdl, polygons.offset)
+	  && typ->readUInt32(hdl, polygons.size)))
 		return false;
 
-	if (!(file->readUInt16(hdl, tmp16) && file->readUInt16(hdl, tmp16)))
+	if (!(typ->readUInt16(hdl, tmp16) && typ->readUInt16(hdl, tmp16)))
 		return false;
 
-	if (!(file->readUInt32(hdl, points.arrayOffset)
-	  && file->readUInt16(hdl, points.arrayItemSize)
-	  && file->readUInt32(hdl, points.arraySize)
-	  && file->readUInt32(hdl, lines.arrayOffset)
-	  && file->readUInt16(hdl, lines.arrayItemSize)
-	  && file->readUInt32(hdl, lines.arraySize)
-	  && file->readUInt32(hdl, polygons.arrayOffset)
-	  && file->readUInt16(hdl, polygons.arrayItemSize)
-	  && file->readUInt32(hdl, polygons.arraySize)
-	  && file->readUInt32(hdl, order.arrayOffset)
-	  && file->readUInt16(hdl, order.arrayItemSize)
-	  && file->readUInt32(hdl, order.arraySize)))
+	if (!(typ->readUInt32(hdl, points.arrayOffset)
+	  && typ->readUInt16(hdl, points.arrayItemSize)
+	  && typ->readUInt32(hdl, points.arraySize)
+	  && typ->readUInt32(hdl, lines.arrayOffset)
+	  && typ->readUInt16(hdl, lines.arrayItemSize)
+	  && typ->readUInt32(hdl, lines.arraySize)
+	  && typ->readUInt32(hdl, polygons.arrayOffset)
+	  && typ->readUInt16(hdl, polygons.arrayItemSize)
+	  && typ->readUInt32(hdl, polygons.arraySize)
+	  && typ->readUInt32(hdl, order.arrayOffset)
+	  && typ->readUInt16(hdl, order.arrayItemSize)
+	  && typ->readUInt32(hdl, order.arraySize)))
 		return false;
 
-	if (!(parsePoints(file, hdl, points) && parseLines(file, hdl, lines)
-	  && parsePolygons(file, hdl, polygons)
-	  && parseDrawOrder(file, hdl, order))) {
+	if (!(parsePoints(typ, hdl, points) && parseLines(typ, hdl, lines)
+	  && parsePolygons(typ, hdl, polygons)
+	  && parseDrawOrder(typ, hdl, order))) {
 		qWarning("%s: Invalid TYP file, using default style",
-		  qPrintable(file->fileName()));
+		  qPrintable(typ->fileName()));
 		return false;
 	}
 
 	return true;
 }
 
-Style::Style(qreal ratio, SubFile *typ)
+Style::Style(QFile *file, qreal ratio, SubFile *typ)
 {
 	_large = pixelSizeFont(16);
 	_normal = pixelSizeFont(14);
@@ -1326,7 +1326,7 @@ Style::Style(qreal ratio, SubFile *typ)
 	defaultPointStyle(ratio);
 
 	if (typ)
-		parseTYPFile(typ);
+		parseTYPFile(file, typ);
 }
 
 const Style::Line &Style::line(quint32 type) const
diff --git a/src/map/IMG/style.h b/src/map/IMG/style.h
index 9bfc47b1..1374083c 100644
--- a/src/map/IMG/style.h
+++ b/src/map/IMG/style.h
@@ -104,7 +104,7 @@ public:
 	};
 
 
-	Style(qreal ratio, SubFile *typ = 0);
+	Style(QFile *file, qreal ratio, SubFile *typ = 0);
 
 	const Line &line(quint32 type) const;
 	const Polygon &polygon(quint32 type) const;
@@ -171,7 +171,7 @@ private:
 		bool extended;
 	};
 
-	bool parseTYPFile(SubFile *file);
+	bool parseTYPFile(QFile *file, SubFile *typ);
 	bool parsePoints(SubFile *file, SubFile::Handle &hdl,
 	  const Section &section);
 	bool parsePoint(SubFile *file, SubFile::Handle &hdl,
diff --git a/src/map/IMG/subfile.cpp b/src/map/IMG/subfile.cpp
index efdee7ab..90576774 100644
--- a/src/map/IMG/subfile.cpp
+++ b/src/map/IMG/subfile.cpp
@@ -27,9 +27,9 @@ bool SubFile::seek(Handle &handle, quint32 pos) const
 		int blockNum = pos >> BLOCK_BITS;
 
 		if (handle._blockNum != blockNum) {
-			if (!handle._file.seek((quint64)blockNum << BLOCK_BITS))
+			if (!handle._file->seek((quint64)blockNum << BLOCK_BITS))
 				return false;
-			if (handle._file.read(handle._data.data(), (1<<BLOCK_BITS)) < 0)
+			if (handle._file->read(handle._data.data(), (1<<BLOCK_BITS)) < 0)
 				return false;
 			handle._blockNum = blockNum;
 		}
diff --git a/src/map/IMG/subfile.h b/src/map/IMG/subfile.h
index d0eeaee8..8d76396a 100644
--- a/src/map/IMG/subfile.h
+++ b/src/map/IMG/subfile.h
@@ -18,25 +18,34 @@ public:
 	class Handle
 	{
 	public:
-		Handle(const SubFile *subFile)
-		  : _blockNum(-1), _blockPos(-1), _pos(-1)
+		Handle(QFile *file, const SubFile *subFile)
+		  : _file(file), _blockNum(-1), _blockPos(-1), _pos(-1), _delete(false)
 		{
 			if (!subFile)
 				return;
 
+			if (!_file) {
+				_file = new QFile(subFile->fileName());
+				_file->open(QIODevice::ReadOnly | QIODevice::Unbuffered);
+				_delete = true;
+			}
 			_data.resize(subFile->blockSize());
-			_file.setFileName(subFile->fileName());
-			_file.open(QIODevice::ReadOnly | QIODevice::Unbuffered);
+		}
+		~Handle()
+		{
+			if (_delete)
+				delete _file;
 		}
 
 	private:
 		friend class SubFile;
 
-		QFile _file;
+		QFile *_file;
 		QByteArray _data;
 		int _blockNum;
 		int _blockPos;
 		int _pos;
+		bool _delete;
 	};
 
 	SubFile(const IMGData *img)
diff --git a/src/map/IMG/trefile.cpp b/src/map/IMG/trefile.cpp
index 7385382b..959a6545 100644
--- a/src/map/IMG/trefile.cpp
+++ b/src/map/IMG/trefile.cpp
@@ -49,9 +49,9 @@ TREFile::~TREFile()
 	clear();
 }
 
-bool TREFile::init()
+bool TREFile::init(QFile *file)
 {
-	Handle hdl(this);
+	Handle hdl(file, this);
 	quint8 locked, levels[64];
 	quint16 hdrLen;
 	qint32 north, east, south, west;
@@ -154,9 +154,9 @@ int TREFile::readExtEntry(Handle &hdl, quint32 &polygons, quint32 &lines,
 	return rb;
 }
 
-bool TREFile::load(int idx)
+bool TREFile::load(QFile *file, int idx)
 {
-	Handle hdl(this);
+	Handle hdl(file, this);
 	QList<SubDiv*> sl;
 	SubDiv *s = 0;
 	SubDivTree *tree = new SubDivTree();
@@ -282,7 +282,7 @@ void TREFile::clear()
 	_subdivs.clear();
 }
 
-const TREFile::SubDivTree *TREFile::subdivs(const Zoom &zoom)
+const TREFile::SubDivTree *TREFile::subdivs(QFile *file, const Zoom &zoom)
 {
 	int idx = -1;
 
@@ -296,7 +296,7 @@ const TREFile::SubDivTree *TREFile::subdivs(const Zoom &zoom)
 	if (idx < 0)
 		return 0;
 
-	if (!_subdivs.contains(_levels.at(idx).level) && !load(idx))
+	if (!_subdivs.contains(_levels.at(idx).level) && !load(file, idx))
 		return 0;
 
 	return _subdivs.value(_levels.at(idx).level);
@@ -309,10 +309,10 @@ static bool cb(SubDiv *subdiv, void *context)
 	return true;
 }
 
-QList<SubDiv*> TREFile::subdivs(const RectC &rect, const Zoom &zoom)
+QList<SubDiv*> TREFile::subdivs(QFile *file, const RectC &rect, const Zoom &zoom)
 {
 	QList<SubDiv*> list;
-	const SubDivTree *tree = subdivs(zoom);
+	const SubDivTree *tree = subdivs(file, zoom);
 	double min[2], max[2];
 
 	min[0] = rect.left();
diff --git a/src/map/IMG/trefile.h b/src/map/IMG/trefile.h
index 0bc1cc6c..c309f365 100644
--- a/src/map/IMG/trefile.h
+++ b/src/map/IMG/trefile.h
@@ -24,11 +24,11 @@ public:
 	  : SubFile(gmp, offset), _flags(0), _extItemSize(0) {}
 	~TREFile();
 
-	bool init();
+	bool init(QFile *file);
 	void clear();
 
 	const RectC &bounds() const {return _bounds;}
-	QList<SubDiv*> subdivs(const RectC &rect, const Zoom &zoom);
+	QList<SubDiv*> subdivs(QFile *file, const RectC &rect, const Zoom &zoom);
 	quint32 shift(quint8 bits) const
 	  {return (bits == _levels.last().bits) ? (_flags >> 0xb) & 7 : 0;}
 	QVector<Zoom> zooms() const;
@@ -41,8 +41,8 @@ private:
 	};
 	typedef RTree<SubDiv*, double, 2> SubDivTree;
 
-	bool load(int idx);
-	const SubDivTree *subdivs(const Zoom &zoom);
+	bool load(QFile *file, int idx);
+	const SubDivTree *subdivs(QFile *file, const Zoom &zoom);
 	int readExtEntry(Handle &hdl, quint32 &polygons, quint32 &lines,
 	  quint32 &points);
 
diff --git a/src/map/IMG/vectortile.cpp b/src/map/IMG/vectortile.cpp
index 19a83dd1..850a3f60 100644
--- a/src/map/IMG/vectortile.cpp
+++ b/src/map/IMG/vectortile.cpp
@@ -40,20 +40,20 @@ SubFile *VectorTile::file(SubFile::Type type)
 	}
 }
 
-bool VectorTile::init()
+bool VectorTile::init(QFile *file)
 {
-	if (_gmp && !initGMP())
+	if (_gmp && !initGMP(file))
 		return false;
 
-	if (!(_tre && _tre->init() && _rgn))
+	if (!(_tre && _tre->init(file) && _rgn))
 		return false;
 
 	return true;
 }
 
-bool VectorTile::initGMP()
+bool VectorTile::initGMP(QFile *file)
 {
-	SubFile::Handle hdl(_gmp);
+	SubFile::Handle hdl(file, _gmp);
 	quint32 tre, rgn, lbl, net, nod, dem;
 
 	if (!(_gmp->seek(hdl, 0x19) && _gmp->readUInt32(hdl, tre)
@@ -118,7 +118,7 @@ void VectorTile::clear()
 	_demLoaded = 0;
 }
 
-void VectorTile::polys(const RectC &rect, const Zoom &zoom,
+void VectorTile::polys(QFile *file, const RectC &rect, const Zoom &zoom,
   QList<MapData::Poly> *polygons, QList<MapData::Poly> *lines,
   MapData::PolyCache *cache, QMutex *lock)
 {
@@ -133,10 +133,10 @@ void VectorTile::polys(const RectC &rect, const Zoom &zoom,
 	}
 
 	if (!_loaded) {
-		rgnHdl = new SubFile::Handle(_rgn);
-		lblHdl = new SubFile::Handle(_lbl);
-		netHdl = new SubFile::Handle(_net);
-		nodHdl = new SubFile::Handle(_nod);
+		rgnHdl = new SubFile::Handle(file, _rgn);
+		lblHdl = new SubFile::Handle(file, _lbl);
+		netHdl = new SubFile::Handle(file, _net);
+		nodHdl = new SubFile::Handle(file, _nod);
 
 		if (!load(*rgnHdl, *lblHdl, *netHdl, *nodHdl)) {
 			lock->unlock();
@@ -145,7 +145,7 @@ void VectorTile::polys(const RectC &rect, const Zoom &zoom,
 		}
 	}
 
-	QList<SubDiv*> subdivs = _tre->subdivs(rect, zoom);
+	QList<SubDiv*> subdivs = _tre->subdivs(file, rect, zoom);
 	for (int i = 0; i < subdivs.size(); i++) {
 		SubDiv *subdiv = subdivs.at(i);
 
@@ -154,9 +154,9 @@ void VectorTile::polys(const RectC &rect, const Zoom &zoom,
 			quint32 shift = _tre->shift(subdiv->bits());
 
 			if (!rgnHdl) {
-				rgnHdl = new SubFile::Handle(_rgn);
-				lblHdl = new SubFile::Handle(_lbl);
-				netHdl = new SubFile::Handle(_net);
+				rgnHdl = new SubFile::Handle(file, _rgn);
+				lblHdl = new SubFile::Handle(file, _lbl);
+				netHdl = new SubFile::Handle(file, _net);
 			}
 
 			if (!subdiv->initialized() && !_rgn->subdivInit(*rgnHdl, subdiv))
@@ -175,9 +175,9 @@ void VectorTile::polys(const RectC &rect, const Zoom &zoom,
 
 			if (_net && _net->hasLinks()) {
 				if (!nodHdl)
-					nodHdl = new SubFile::Handle(_nod);
+					nodHdl = new SubFile::Handle(file, _nod);
 				if (!nodHdl2)
-					nodHdl2 = new SubFile::Handle(_nod);
+					nodHdl2 = new SubFile::Handle(file, _nod);
 				_rgn->links(*rgnHdl, subdiv, shift, _net, *netHdl, _nod, *nodHdl,
 				  *nodHdl2, _lbl, *lblHdl, &polys->lines);
 			}
@@ -199,7 +199,7 @@ void VectorTile::polys(const RectC &rect, const Zoom &zoom,
 	delete rgnHdl; delete lblHdl; delete netHdl; delete nodHdl; delete nodHdl2;
 }
 
-void VectorTile::points(const RectC &rect, const Zoom &zoom,
+void VectorTile::points(QFile *file, const RectC &rect, const Zoom &zoom,
   QList<MapData::Point> *points, MapData::PointCache *cache, QMutex *lock)
 {
 	SubFile::Handle *rgnHdl = 0, *lblHdl = 0;
@@ -212,10 +212,10 @@ void VectorTile::points(const RectC &rect, const Zoom &zoom,
 	}
 
 	if (!_loaded) {
-		rgnHdl = new SubFile::Handle(_rgn);
-		lblHdl = new SubFile::Handle(_lbl);
-		SubFile::Handle nodHdl(_nod);
-		SubFile::Handle netHdl(_net);
+		rgnHdl = new SubFile::Handle(file, _rgn);
+		lblHdl = new SubFile::Handle(file, _lbl);
+		SubFile::Handle nodHdl(file, _nod);
+		SubFile::Handle netHdl(file, _net);
 
 		if (!load(*rgnHdl, *lblHdl, netHdl, nodHdl)) {
 			lock->unlock();
@@ -224,15 +224,15 @@ void VectorTile::points(const RectC &rect, const Zoom &zoom,
 		}
 	}
 
-	QList<SubDiv*> subdivs = _tre->subdivs(rect, zoom);
+	QList<SubDiv*> subdivs = _tre->subdivs(file, rect, zoom);
 	for (int i = 0; i < subdivs.size(); i++) {
 		SubDiv *subdiv = subdivs.at(i);
 
 		QList<MapData::Point> *pl = cache->object(subdiv);
 		if (!pl) {
 			if (!rgnHdl) {
-				rgnHdl = new SubFile::Handle(_rgn);
-				lblHdl = new SubFile::Handle(_lbl);
+				rgnHdl = new SubFile::Handle(file, _rgn);
+				lblHdl = new SubFile::Handle(file, _lbl);
 			}
 
 			if (!subdiv->initialized() && !_rgn->subdivInit(*rgnHdl, subdiv))
@@ -258,7 +258,7 @@ void VectorTile::points(const RectC &rect, const Zoom &zoom,
 	delete rgnHdl; delete lblHdl;
 }
 
-void VectorTile::elevations(const RectC &rect, const Zoom &zoom,
+void VectorTile::elevations(QFile *file, const RectC &rect, const Zoom &zoom,
   QList<MapData::Elevation> *elevations, MapData::ElevationCache *cache,
   QMutex *lock)
 {
@@ -272,7 +272,7 @@ void VectorTile::elevations(const RectC &rect, const Zoom &zoom,
 	}
 
 	if (!_demLoaded) {
-		hdl = new SubFile::Handle(_dem);
+		hdl = new SubFile::Handle(file, _dem);
 
 		if (!loadDem(*hdl)) {
 			lock->unlock();
@@ -293,7 +293,7 @@ void VectorTile::elevations(const RectC &rect, const Zoom &zoom,
 
 		if (!el) {
 			if (!hdl)
-				hdl = new SubFile::Handle(_dem);
+				hdl = new SubFile::Handle(file, _dem);
 
 			el = _dem->elevations(*hdl, level, tile);
 			if (!el->m.isNull())
diff --git a/src/map/IMG/vectortile.h b/src/map/IMG/vectortile.h
index ca663460..6b9c2610 100644
--- a/src/map/IMG/vectortile.h
+++ b/src/map/IMG/vectortile.h
@@ -21,7 +21,7 @@ public:
 		delete _dem; delete _gmp;
 	}
 
-	bool init();
+	bool init(QFile *file);
 	void clear();
 
 	const RectC &bounds() const {return _tre->bounds();}
@@ -30,12 +30,12 @@ public:
 
 	SubFile *file(SubFile::Type type);
 
-	void polys(const RectC &rect, const Zoom &zoom,
+	void polys(QFile *file, const RectC &rect, const Zoom &zoom,
 	  QList<MapData::Poly> *polygons, QList<MapData::Poly> *lines,
 	  MapData::PolyCache *cache, QMutex *lock);
-	void points(const RectC &rect, const Zoom &zoom,
+	void points(QFile *file, const RectC &rect, const Zoom &zoom,
 	  QList<MapData::Point> *points, MapData::PointCache *cache, QMutex *lock);
-	void elevations(const RectC &rect, const Zoom &zoom,
+	void elevations(QFile *file, const RectC &rect, const Zoom &zoom,
 	  QList<MapData::Elevation> *elevations, MapData::ElevationCache *cache,
 	  QMutex *lock);
 
@@ -78,7 +78,7 @@ public:
 	}
 
 private:
-	bool initGMP();
+	bool initGMP(QFile *file);
 	bool load(SubFile::Handle &rgnHdl, SubFile::Handle &lblHdl,
 	  SubFile::Handle &netHdl, SubFile::Handle &nodHdl);
 	bool loadDem(SubFile::Handle &demHdl);
diff --git a/src/map/imgmap.cpp b/src/map/imgmap.cpp
index d120ccf5..9410d555 100644
--- a/src/map/imgmap.cpp
+++ b/src/map/imgmap.cpp
@@ -276,7 +276,7 @@ double IMGMap::elevation(const Coordinates &c)
 	if (d->hasDEM()) {
 		QList<MapData::Elevation> tiles;
 
-		d->elevations(RectC(c, Coordinates(c.lon() + DELTA, c.lat() - DELTA)),
+		d->elevations(0, RectC(c, Coordinates(c.lon() + DELTA, c.lat() - DELTA)),
 		  d->zooms().max(), &tiles);
 		DEMTree tree(tiles);