[docs]def flip(img, y_flip=False, x_flip=False, copy=False):
"""Flip an image in vertical or horizontal direction as specified.
Args:
img (~numpy.ndarray): An array that gets flipped. This is in CHW
format.
y_flip (bool): Flip in vertical direction.
x_flip (bool): Flip in horizontal direction.
copy (bool): If False, a view of :obj:`img` will be returned.
Returns:
Transformed :obj:`img` in CHW format.
"""
assert img.ndim == 3, 'The dimension of image must be 3'
if y_flip:
img = img[:, ::-1, :]
if x_flip:
img = img[:, :, ::-1]
if copy:
img = img.copy()
return img