'Returns the contents of this image as a sequence object
containing pixel values.  The sequence object is flattened, so
that values for line one follow directly after the values of
line zero, and so on.
Note that the sequence object returned by this method is an
internal PIL data type, which only supports certain sequence
operations.  To convert it to an ordinary sequence (e.g. for
printing), use **list(im.getdata())**.
:param band: What band to return.  The default is to return
all bands.  To return a single band, pass in the index
value (e.g. 0 to get the "R" band from an "RGB" image).
:returns: A sequence-like object.'

def getdata(self, band=None):

    self.load()
    if (band is not None):
        return self.im.getband(band)
    return self.im
