Lighting control data generation method and lighting control data generation device

A lighting control data generation method for generating lighting control data for controlling a plurality of light sources in a head-up display device, the lighting control data generation method comprising:

• a measurement point specification step in which a measurement point specification unit specifies a plurality of measurement points in accordance with a luminance of light emitted by the light sources at each of a plurality of output levels set to mutually different values by a light source control unit that controls the light sources with reference to the lighting control data;
• and
• an output characteristic acquisition step in which an output characteristic acquisition unit acquires output characteristics by interpolating between the specified plurality of measurement points,
• wherein in the measurement point specification step, when a required luminance exceeds a threshold value, a first specified number of measurement points are specified, and when the required luminance is less than or equal to the threshold value, a second specified number of measurement points that are larger than the first specified number of measurement points are specified.