1. An image processing device, comprising: a filtering unit which filters an input image with variable frequency characteristics; an edge detection unit which detects magnitudes of edges appearing in the input image; and a degree-of-white-background-likeliness detection unit which detects degrees of white-background likeliness in respect of local areas of the input image, wherein said filtering unit changes the variable frequency characteristics in response to the magnitudes of edges and to the degrees of white-background likeliness.