Understanding Facial Hyperpigmentation
Melanin is the primary pigment responsible for human skin coloration, synthesized by melanocytes in the basal layer of the epidermis. Under ultraviolet (UV) radiation or hormonal stimuli, localized clusters of hyperactive melanocytes produce excess melanin, manifesting as solar lentigines (sun spots), post-inflammatory hyperpigmentation (PIH), or melasma.
CIE L*a*b* Chrominance Separation
Dr Maher Vision AI v4.0 analyzes skin color in the perceptually uniform CIE L*a*b* color space. The L* channel measures perceptual lightness, while a* and b* measure red-green and yellow-blue chroma. A spot counts as pigment only when it is darker than the surrounding skin and its colour changes too, which separates pigment from ordinary shading; elongated marks such as folds are discarded. Patches larger than about 1.5 cm cannot be told apart from lighting and are not captured.
Frequently Asked Questions
Can the scan determine whether pigmentation is epidermal or dermal?
No. Differentiating epidermal from deeper dermal pigmentation requires clinical Wood’s lamp examination or dermatoscopy.