Photographing Alopecia: How Many Pixels Are Needed for Clinical Evaluation?
TLDR Higher resolution images are needed to identify scarring and fine hair in alopecia.
The study investigated the minimal image resolution necessary for accurate clinical assessment of alopecia using automated image analysis. It focused on detecting abnormal hair density, scarring, and vellus hair. Expert clinicians evaluated images at various resolutions, finding that low resolutions sufficed for detecting alopecia, but higher resolutions were needed for identifying scarring and vellus hair. The accuracy of alopecia detection by human observers mirrored that of a neural network, suggesting that the resolution required by experts could set an upper bound for future image processing algorithms.
