Pore density
How visible the pores are across a region of skin, measured pixel by pixel rather than by eye. The metric that separates real texture change from a bad-lighting day.
Definition
Pore density is a measurement of how many visible pores are present in a given area of skin, combined with how prominent each pore appears. It is a proxy for skin texture in the regions where pores are largest and most visible, typically the nose, central cheeks, and lower forehead. A higher pore density measurement means more visible pores in the region.
How it is measured
Pore visibility is enhanced relative to surrounding skin by image processing operators. Two common ones used in dermatology research and in Trace:
- CLAHE (Contrast Limited Adaptive Histogram Equalization). Increases local contrast in small image patches without amplifying global noise. This makes shallow pores visible enough to count.
- Black-hat differential. A morphological operator that highlights small dark spots (such as pore openings) against a brighter background. Black-hat-processed images make pore-like structures pop out of the texture.
Combining the two and applying region-of-interest sampling across forehead, cheeks, and nose gives a per-scan pore density number that is fair to compare across days, provided the capture is standardized.
Why this is useful
Pore visibility changes with hydration, oil production, sun exposure, and certain actives over weeks. A retinoid that is working should slowly reduce visible pore prominence over a month or more, not in days. A clogging product can do the opposite. A single mirror impression of 'my pores look big' tells you nothing because pore appearance changes day to day with lighting and sebum. A daily standardized measurement of pore density across a thirty day single-product test is what gives you a real trend.
How Trace measures pore density
Trace runs CLAHE plus black-hat on each daily scan, samples specific facial regions (the same regions every day, anchored to the face mesh), and outputs a pore density score that contributes to your pore metric trend. All computation is on-device.
Pore size is partly genetic and partly state-dependent (oil, hydration, age). No skincare product permanently shrinks pores. The realistic outcome you are tracking is a downward trend in visible pore density, not a reset to zero.
Frequently asked
Can skincare shrink pores?
Not permanently. Visible pore prominence can decrease as oil production normalizes, hydration improves, and exfoliation reduces clogging. The number you can actually move is pore density, which is what Trace measures.
Why does pore density change day to day?
Oil production, hydration, and lighting all shift pore visibility. This is why a single mirror check is unreliable. A standardized daily scan across thirty days averages out the noise and shows the real trend.
How does Trace measure pore density?
Combines CLAHE local contrast enhancement with a black-hat morphological filter to make pore openings visible, then samples specific face regions consistently across scans. All on device.