fixed indicies - I think they might vary depending on file so this could cause problems

nd2reader/model/__init__.py

@@ -62,13 +62,19 @@ class Image(object):
 
     @property
     def timestamp(self):
-        # TODO: Convert to datetime object
+        """
+        The number of seconds after the beginning of the acquisition that the image was taken. Note that for a given field
+        of view and z-level offset, if you have images of multiple channels, they will all be given the same timestamp.
+        No, this doesn't make much sense. But that's how ND2s are structured, so if your experiment depends on millisecond
+        accuracy, you need to find an alternative imaging system.
+
+        """
         return self._timestamp / 1000.0
 
     @property
     def data(self):
         if self._data is None:
-            self._data = np.reshape(self._raw_data, (self._height, self._width))
+            self._data = np.reshape(self._raw_data, (self._height, self._width)).astype(np.float64)
         return self._data
 
     @property

nd2reader/service/__init__.py

@@ -29,7 +29,7 @@ class BaseNd2(object):
     def channels(self):
         metadata = self._metadata['ImageMetadataSeq']['SLxPictureMetadata']['sPicturePlanes']
         try:
-            validity = self._metadata['ImageMetadata']['SLxExperiment']['ppNextLevelEx']['']['ppNextLevelEx']['']['pItemValid']
+            validity = self._metadata['ImageMetadata']['SLxExperiment']['ppNextLevelEx'][''][0]['ppNextLevelEx'][''][0]['pItemValid']
         except KeyError:
             # If none of the channels have been deleted, there is no validity list, so we just make one
             validity = [True for i in metadata]
@@ -69,7 +69,7 @@ class BaseNd2(object):
         NIS Elements can figure it out, but we haven't found it yet.
 
         """
-        return sum(self._metadata['ImageMetadata']['SLxExperiment']['ppNextLevelEx']['']['pItemValid'])
+        return sum(self._metadata['ImageMetadata']['SLxExperiment']['ppNextLevelEx'][''][0]['pItemValid'])
 
     @property
     def channel_count(self):