Here is disclosed a disposable diaper, which includes a liquid-absorbent zone in a crotch region having first through fourth sections. A single-sided conductor patterned film which has a conductor pattern formed only one side of a resin film and an opening formed in the resin film so as to expose an electrode is laminated on the single-sided conductor patterned films. For the controlled feeding of energy into the pumping medium, the screw is axially displaceable in the screw casing. Four corners on a proximal periphery of the head are protruded out of an outer peripheral face of the post so as to form an engaging portion which bites into a wall face of an attaching hole in a boss portion of the button. The invention includes novel approaches of introducing pseudo random shuffles into the processes of dictionary coding, Huffman coding, and arithmetic coding. The image is divided into a plurality of blocks, the number of pixels which are determined to be an edge pixel in each block is counted, and whether each of pixels in each block is a halftone pixel is determined on the basis of the number of the pixels which are determined to be an edge pixel in the block.