1. An information communication method of transmitting a signal using a change in luminance, the information communication method comprising: determining a pattern of the change in luminance, by modulating a first signal to be transmitted; transmitting the first signal by a light emitter changing in luminance according to the determined pattern of the change in luminance; determining a sequence of first and second image units that have different luminance values from each other, by modulating a second signal to be transmitted; and displaying an image including the first and second image units arranged according to the determined sequence, wherein in the determining of a sequence: for one of 0 and 1 included in the second signal, the sequence of the first and second image units is determined so that a first image unit group of one or more consecutive first image units and a second image unit group of one or more consecutive second image units are consecutive where the first image unit group and the second image unit group have a same number of image units as each other; and for the other one of 0 and 1 included in the second signal, the sequence of the first and second image units is determined so that the first image unit group and the second image unit group are consecutive where the first image unit group and the second image unit group have different numbers of image units from each other.