def reload(self, n=None):
"""Reload one or more images from file.
Parameters
----------
n : None or int
The number of the image to reload. If None (default), all images in
memory are reloaded. If `n` specifies an image not yet in memory,
it is loaded.
Returns
-------
None
Notes
-----
`reload` is used to reload all images in memory when `as_grey` is
changed.
"""
if n is not None:
n = self._check_numimg(n)
idx = n % len(self.data)
self.data[idx] = imread(self.files[n], self.as_grey,
dtype=self._dtype)
else:
for idx, img in enumerate(self.data):
if img is not None:
self.data[idx] = imread(self.files[idx], self.as_grey,
dtype=self._dtype)
def __getitem__(self, n):
"""Return image n in the collection.
Loading is done on demand.
Parameters
----------
n : int
The image number to be returned.
Returns
-------
img : ndarray
The `n`-th image in the collection.
"""
n = self._check_imgnum(n)
idx = n % len(self.data)
if (self.conserve_memory and n != self._cached) or (self.data[idx] is None):
self.data[idx] = imread(self.files[n], self.as_grey,
dtype=self._dtype)
self._cached = n
return self.data[idx]
