RF: Use consistent logic for ECAT, Minc1 and PARREC proxies

Author: effigies

nibabel/ecat.py

@@ -706,9 +706,10 @@ def __array__(self):
 
     def get_scaled(self, dtype=None):
         data = self.__array__()
-        if dtype is not None and np.dtype(dtype) > data.dtype:
-            data = data.astype(dtype)
-        return data
+        if dtype is None:
+            return data
+        final_type = np.promote_types(data.dtype, dtype)
+        return data.astype(final_type, copy=False)
 
     def __getitem__(self, sliceobj):
         """ Return slice `sliceobj` from ECAT data, optimizing if possible

nibabel/minc1.py

@@ -263,9 +263,10 @@ def is_proxy(self):
 
     def _get_scaled(self, dtype, slicer):
         data = self.minc_file.get_scaled_data(slicer)
-        if dtype is not None and np.dtype(dtype) > data.dtype:
-            data = data.astype(dtype)
-        return data
+        if dtype is None:
+            return data
+        final_type = np.promote_types(data.dtype, dtype)
+        return data.astype(final_type, copy=False)
 
     def get_scaled(self, dtype=None):
         return self._get_scaled(dtype=dtype, slicer=())

nibabel/parrec.py

@@ -633,12 +633,6 @@ def dtype(self):
     def is_proxy(self):
         return True
 
-    def get_unscaled(self):
-        with ImageOpener(self.file_like) as fileobj:
-            return _data_from_rec(fileobj, self._rec_shape, self._dtype,
-                                  self._slice_indices, self._shape,
-                                  mmap=self._mmap)
-
     def _get_unscaled(self, slicer):
         indices = self._slice_indices
         if slicer == ():
@@ -675,6 +669,9 @@ def _get_scaled(self, dtype, slicer):
         return raw_data * slopes[slicer].astype(final_type) + inters[slicer].astype(final_type)
 
 
+    def get_unscaled(self):
+        return self._get_unscaled(slicer=())
+
     def get_scaled(self, dtype=None):
         return self._get_scaled(dtype=dtype, slicer=())