diff --git a/pyqtgraph/exporters/HDF5Exporter.py b/pyqtgraph/exporters/HDF5Exporter.py
index cc8b5733..584a9f71 100644
--- a/pyqtgraph/exporters/HDF5Exporter.py
+++ b/pyqtgraph/exporters/HDF5Exporter.py
@@ -42,14 +42,20 @@ class HDF5Exporter(Exporter):
         dsname = self.params['Name']
         fd = h5py.File(fileName, 'a') # forces append to file... 'w' doesn't seem to "delete/overwrite"
         data = []
-        
+
         appendAllX = self.params['columnMode'] == '(x,y) per plot'
-        for i,c in enumerate(self.item.curves):
+        #print dir(self.item.curves[0])
+        tlen = 0
+        for i, c in enumerate(self.item.curves):
             d = c.getData()
+            if i > 0 and len(d[0]) != tlen:
+                raise ValueError ("HDF5 Export requires all curves in plot to have same length")
             if appendAllX or i == 0:
                 data.append(d[0])
+                tlen = len(d[0])
             data.append(d[1])
-                
+
+
         fdata = numpy.array(data).astype('double')
         dset = fd.create_dataset(dsname, data=fdata)
         fd.close()
diff --git a/pyqtgraph/exporters/ImageExporter.py b/pyqtgraph/exporters/ImageExporter.py
index 4dc07d84..ffa59091 100644
--- a/pyqtgraph/exporters/ImageExporter.py
+++ b/pyqtgraph/exporters/ImageExporter.py
@@ -27,6 +27,7 @@ class ImageExporter(Exporter):
             {'name': 'height', 'type': 'int', 'value': int(tr.height()), 'limits': (0, None)},
             {'name': 'antialias', 'type': 'bool', 'value': True},
             {'name': 'background', 'type': 'color', 'value': bg},
+            {'name': 'invertValue', 'type': 'bool', 'value': False}
         ])
         self.params.param('width').sigValueChanged.connect(self.widthChanged)
         self.params.param('height').sigValueChanged.connect(self.heightChanged)
@@ -67,13 +68,15 @@ class ImageExporter(Exporter):
         w, h = self.params['width'], self.params['height']
         if w == 0 or h == 0:
             raise Exception("Cannot export image with size=0 (requested export size is %dx%d)" % (w,h))
-        bg = np.empty((self.params['width'], self.params['height'], 4), dtype=np.ubyte)
+        bg = np.empty((self.params['height'], self.params['width'], 4), dtype=np.ubyte)
         color = self.params['background']
         bg[:,:,0] = color.blue()
         bg[:,:,1] = color.green()
         bg[:,:,2] = color.red()
         bg[:,:,3] = color.alpha()
-        self.png = fn.makeQImage(bg, alpha=True)
+
+        self.png = fn.makeQImage(bg, alpha=True, copy=False, transpose=False)
+        self.bg = bg
         
         ## set resolution of image:
         origTargetRect = self.getTargetRect()
@@ -91,6 +94,12 @@ class ImageExporter(Exporter):
             self.setExportMode(False)
         painter.end()
         
+        if self.params['invertValue']:
+            mn = bg[...,:3].min(axis=2)
+            mx = bg[...,:3].max(axis=2)
+            d = (255 - mx) - mn
+            bg[...,:3] += d[...,np.newaxis]
+        
         if copy:
             QtGui.QApplication.clipboard().setImage(self.png)
         elif toBytes: