In a converting method for converting luminance of an input video in order to display the video on a display device, the luminance of the video is a first luminance value in a first luminance range where a maximum luminance value is defined as a first maximum luminance value that exceeds 100 nit. The method includes acquiring a first luminance signal indicating a first luminance value of the video, selecting a luminance converting process to be executed from among a plurality of luminance converting processes based on a reference luminance value corresponding to reference reflectance included in first meta data of the acquired first luminance signal, converting the first luminance value indicated by the acquired first luminance signal into a second luminance value in a second luminance range where a maximum luminance value is defined as a second maximum luminance value that is smaller than the first maximum luminance value and larger than 100 nit based on the selected luminance converting process.