Patent ID: 7025677

Claim:
A computer-readable recording medium, comprising a game emulator program recorded thereon for executing a game program that is designed for a first game machine using a display device of a first resolution on a second game machine using a display device of a second resolution lower than the first resolution, the game program including data of a background image of the first resolution for forming a background of a game image and data of an object image to be overlaid on the background image, wherein: in a predetermined frame in which the game image is generated by executing the game program, the game emulator program instructs the second game machine to perform the steps of: determining, for horizontal lines and/or vertical lines of the background image, a first decimation line based on which the background image is decimated by lines; converting the resolution of the background image to the second resolution by successively outputting lines of the background image while skipping a line of the background image corresponding to the first decimation line; generating lines of a first game image by overlaying the object image on the lines of the background image being outputted when the object image concurs with the lines of the background image being output; and successively supplying the lines of the first game image to the display device of the second resolution, thereby displaying the first game image on the display device of the second resolution; in a next frame following the predetermined frame, the game emulator program instructs the second game machine to perform the steps of: determining one of two lines adjacent to the first decimation line to be a second decimation line; converting the resolution of the background image to the second resolution by successively outputting the lines of the background image while skipping a line of the background image corresponding to the second decimation line; generating lines of a second game image by overlaying the object image on the lines of the background image being outputted when the object image concurs with the lines of the background image being output; and successively supplying the lines of the second game image to the display device of the second resolution, thereby displaying the second game image on the display device of the second resolution.