... initialization of the `previous dc values'.evalSOS :: SOS -> State -> PictureevalSOS (cs,xs) (((y,x),sof),(h0,h1),_,_)= st'apply thePicture (xs,0,0,0])where thePicture = picture ... PictureThe Picture that is the result of jpegDecode is a matrix of pixels, where each pixel consists of a list of integer components with values in the range ;128to127. Theinterpretation of thecomponents ... Notethat, as it is part of the state, the list of `last dc seen' is passed silently from one MCU to thenext.picture :: Dim -> MCUSpec -> StFun (Bits,Int]) Picturepicture dim = map matconcat...