Edge interpolation in map coordinates

[jruebsam]

The problem is described here: scipy/scipy#4075

possible solution:

def map_coordinates_new(image, coords, mode=None, cval=None):
    image = np.pad(image, 1, mode='constant', constant_values=cval)
    return map_coordinates(image, coords + 1, mode=mode, cval=cval)

Could be of interest i.e. for interpolation when rescaling the velocity fields.