Method for obtaining ear drum standard image and the related design of otoscope and software

A non-transitory computer readable recording medium comprising a plurality of instructions, when a processor is connected to an otoscope, execute the instructions and obtain an ear drum standard image, wherein the instructions comprising:

• (a) capturing an ear drum image in a focal length range of an otoscope;
• (b) choosing an ear drum region from the ear drum image, and calculating an area overlapping between the circle sight and the ear drum region;
• (c) if the area does not suffice a standard value, moving the otoscope to another target position, and repeating the steps (a) to (b);
• (d) if the repeat area suffices the standard value, choosing the ear drum image to be an ear drum standard image.