Display medium including information code, information code generating device, and storage medium

An information code generating device comprising:

• at least one processor with a memory storing computer program to generate an information code that is readable by a reader performing a binarization process on luminance, wherein
• the at least one processor is configured to
• generate the information code by superimposing and recording a public code and a hidden code in a common two-dimensional area by arranging a plurality of cells in which either a first symbol or a second symbol to be distinguished by the binarization process is embedded, the public code representing public information, the hidden code representing hidden information, and
• the at least one processor, in the generating of the information code, is configured to
• set a cell in which the first symbol is embedded in the public code and in which the first symbol is embedded in the hidden code to be displayed in black,
• set a cell in which the second symbol is embedded in the public code and in which the second symbol is embedded in the hidden code to be displayed in white,
• set a cell in which the first symbol is embedded in the public code and the second symbol is embedded in the hidden code to be displayed in a first auxiliary color, and
• set a cell in which the second symbol is embedded in the public code and the first symbol is embedded in the hidden code to be displayed in a second auxiliary color so as to be recognized by the reader under white light with a higher luminance than a display in the first auxiliary color and recognized by the reader under light of the first auxiliary color with a lower luminance than a display in the first auxiliary color.

A non-transitory storage medium including an information code generating program, to generate an information code to be read by a reader performing a binarization process on luminance, the information code generating program causes at least one processor to

• generate the information code by superimposing and recording a public code representing public information and a hidden code representing hidden information in a common two-dimensional area, by arranging a plurality of cells in which either a first symbol or a second symbol that can be distinguished by the binarization process is embedded, wherein
• in the generating of the information code, the information code generating program causes the at least one processor to
• set a cell in which the first symbol is embedded in the public code and the first symbol is embedded in the hidden code to be displayed in black,
• set a cell in which the second symbol is embedded in the public code and the second symbol is embedded in the hidden code to be displayed in white,
• set a cell in which the first symbol is embedded by the public code and the second symbol is embedded by the hidden code to be displayed in a first auxiliary color, and
• set a cell in which the second symbol is embedded in the public code and the first symbol is embedded in the hidden code to be displayed in a second auxiliary color so as to be recognized by the reader under white light with a higher luminance than a display in the first auxiliary color and recognized by the reader under light of the first auxiliary color with a lower luminance than a display in the first auxiliary color.