Fix circular import loop

skimage/measure/_regionprops.py

@@ -5,7 +5,6 @@ from scipy import ndimage as ndi
 
 from ._label import label
 from . import _moments
-from ..morphology.convex_hull import convex_hull_image
 
 
 __all__ = ['regionprops', 'perimeter']
@@ -135,6 +134,7 @@ class _RegionProperties(object):
 
     @_cached_property
     def convex_image(self):
+        from ..morphology.convex_hull import convex_hull_image
         return convex_hull_image(self.image)
 
     @property