Two-dimensional code generation device, two-dimensional code generation method, and program

A two-dimensional code generation method, comprising:

• a white point determination step of determining a white point in an environment to output a two-dimensional code;
• a threshold acquisition step of acquiring a threshold of lightness used by a reading device for reading multiple cells in binary, the threshold being represented in a device-independent color space that is based on the white point determined by the white point determination step, and the threshold varying depending on lightness that corresponds to a white color determined by the white point;
• and
• a two-dimensional code generation step of generating the two-dimensional code expressing information by a distribution pattern of multiple cell dots formed by coloring the multiple cells in a color of lightness equal to or higher than the threshold acquired by the threshold acquisition step and in a color of lightness lower than the threshold.

A non-transitory computer-readable recording medium storing a program making a computer execute:

• a white point determination procedure to determine a white point in an environment to output a two-dimensional code;
• a threshold acquisition procedure to acquire a threshold of lightness used by a reading device for reading multiple cells in binary, the threshold being represented in a device-independent color space that is based on the white point determined by the white point determination procedure, and the threshold varying depending on lightness that corresponds to a white color determined by the white point;
• and
• a two-dimensional code generation procedure to generate the two-dimensional code expressing information by a distribution pattern of multiple cell dots formed by coloring the multiple cells in a color of lightness equal to or higher than the threshold acquired by the threshold acquisition procedure and in a color of lightness lower than the threshold.