Context generating circuit for small picture and method the refor

PURPOSE: A circuit for generating a context for a small screen is provided to effectively process an image having a small horizontal size regardless of a buffer memory kind, and to process the image at a high speed. CONSTITUTION: The first generators(121.122) generate contexts of pixel signals having images larger than a horizontal size by one window among the first windows selected according to locations of inputted pixels. The second generator(140) generates a context of a pixel signal having an image smaller than a horizontal size by one window of the second windows selected according to locations of inputted pixels. If an inputted image is an image smaller than the horizontal size, a selector(150) selects the context generated from the second generator(140). If not, the selector selects the contexts generated from the first generators(121,122).