System and method for providing optically coding of information combining color and luminosity

An optical communication transmitter comprising:

• at least one data light emitting element comprising:
• a first group of at least one sub-emitter configured to emit light at respective first color and at least two levels of luminosity;
• and
• a second group of at least one sub-emitter configured to emit light at respective second color mutually complementary to said first color and at least two levels of luminosity;
• and
• a controller coupled to said data light emitting element and operative to modulate light emissions of said data light emitting element by performing the actions of:
• determining length of a repetitive time period not longer than time resolution of a human eye;
• emitting a first sequence of light pulses within said time period, said light pulses comprising pulses of complementary colors and pulses of different levels of luminosity;
• and
• determining order of said colors and levels of luminosity of said first sequence of light pulses emitted within said time period to represent a symbol, and to achieve perceived chromaticity that is substantially constant to a human eye.

An optical receiver comprising:

• an optical sensor;
• and
• a controller controllably coupled to said optical sensor, the controller being operative to demodulate an optical signal detected by said optical sensor by performing actions comprising:
• identifying a clock signal comprising a repeated sequence of light pulses comprising two colors and two levels of luminosity;
• identifying a data signal comprising light pulses comprising two colors and two levels of luminosity;
• determining a symbol using correlation between said light pulses of said clock signal and said light pulses of said data signal;
• wherein said clock signal comprises a repetitive time period not longer than time resolution of a human eye;
• and
• wherein said data signal comprises light pulses of perceived chromaticity and luminosity within said time period that is substantially constant to a human eye.