Something

class Picture(Observable):
    
    EFFECT_NONE        = 0
    EFFECT_BLACK_WHITE = 1
    EFFECT_SEPIA       = 2
    
    TRANS_NONE = 0
    TRANS_FADE = 1
    TRANS_ROLL = 2
    
    def __init__(self, filename):
        Observable.__init__(self)
        self._filename   = filename
        self._startRect  = (0, 0, 1280, 720)
        self._targetRect = (0, 0, 1280, 720)
        self._isDummy    = False