The image particulars of a document image or a part thereof are analyzed and the image particulars of the image are determined according to the outcome of the analysis. Then, the analyzed image particulars of the image are converted to the determined image particulars. Additionally, the analyzed image is divided into component images contained in the image. The image particulars of the image are converted as a result of these processes so that information of the component images for making them as objects of easy viewing with an appropriate data size are output.