In a horse race gaming machine 1, when a regular denomination process of S201 is executed, a regular BET image, wherein the minimum bet amount a player can specify is \u201c1\u201d, is displayed on a sub monitor 113 of a station 101. The adjustable screen arrangement including two screens independently positionable in a number of positions relative to a grinding drum. The first detection unit detects sub-scanning-direction boundary pixels in accordance with the image information. The forward transforms are denoised based on nonlinear mappings derived from quantization values linked to the input image.