Almost all imaging algorithms will prefer the surface that reflects more light. You have plainly more contrast on lighter skin as long as you don't overexpose the sensor.<p>I worked on imaging for diagnostic support of skin lesions and some other skin indications. It did a considerably worse job on black skin. To my defense, black people aren't nearly as likely to develop skin lesions and the diagnostic support isn't a necessity.<p>It should be mentioned that some black people already got into trouble to get the correct diagnosis because physicians thought it to be unlikely.<p>In times of encroaching video surveillance to provide a subjective feeling of security (it is nothing else, snowflake), it might be an advantage.