1. An image processing apparatus for processing original image data, having a given density range, with a predetermined manner to provide processed image data, comprising: means for correcting the density range of the image data to provide density-range-corrected image data corresponding to a distribution of the density of the image data; means for filtering the image data to generate filtered image data; means for synthesizing the density-range-corrected image data provided by said correcting means and the filtered image data provided by said filtering means so as to provide synthesized image data; and means for selecting either one of the density-range-corrected image data provided by said correcting means and the synthesized image data provided by said synthesizing means, in accordance with the density range of the density-range-corrected image data, so as to provide selected image data as said processed image data.