System for composing identification code of subject

A system for composing an identification code of a subject, comprising a feature extraction device, wherein said feature extraction device includes:

• a lighting module configured to be activated to emit light onto a body portion of the subject;
• a photovoltaic module including a plurality of photovoltaic units that are arranged in an array and that are configured to cooperatively receive light reflected off the body portion of the subject which is illuminated by the light from said lighting module, each of said photovoltaic units being configured to convert light energy of the light received thereby into electricity;
• and
• a processing module communicably connected with said lighting module and said photovoltaic module, and including
• a lighting control unit that stores a plurality of feature extraction modes each of which specifies at least one illumination code set, each of the at least one illumination code set including a plurality of illumination codes which are sequentially arranged and each of which corresponds to a specific intensity of illumination, said lighting control unit being configured to, when one of the feature extraction modes is selected, activate said lighting module based on the at least one illumination code set specified by the one of the feature extraction modes thus selected to emit light to sequentially have the specific intensities of illumination that respectively correspond to the illumination codes included in the at least one illumination code set,
• an electrical measurement unit that is configured to measure, for each of said photovoltaic units of said photovoltaic module, an electrical quantity of the electricity which is generated by said photovoltaic unit, and
• an encoding unit that is electrically connected to said electrical measurement unit, that stores a plurality of code parameters which correspond respectively to specific ranges of numerical values, and that is configured to convert the electrical quantity measured for each of said photovoltaic units into one of the code parameters which corresponds to one of the specific ranges of numerical values within which the electrical quantity falls, and to compose an identification code using corresponding ones of the code parameters which are obtained through conversion of the electrical quantities of the electricity which is generated by said photovoltaic units, respectively.