Related Experiment Video
Updated: May 17, 2026

Improved Lipofuscin Models and Quantification of Outer Segment Phagocytosis Capacity in Highly Polarized Human Retinal Pigment Epithelial Cultures
Published on: April 14, 2023
Cross-evaluation of facial hyperpigmented lesions based on fluorescence color image and cross-polarized color image
Eunji Kim1, Dongyoun Kim, Eung H Choi
1Department of Biomedical Engineering, Yonsei University, Wonju, Korea.
Background/Purpose:
Hyperpigmentation is a common skin problem that looks darker than normal skin regions. Accurate evaluation of a hyperpigmented lesion (HPL) is of clinical importance because proper choice of treatment can be dependent on it. This study aimed to differentiate between epidermal and dermal HPLs.
Methods:
Cross-polarized color images (CPCIs) and fluorescence color images (FCIs) were acquired from the same facial regions. Contrast-limited adaptive histogram equalization (CLAHE) was employed to enhance the image contrast and a fuzzy c-means algorithm was implemented to extract the HPLs. The HPLs were superimposed to investigate the difference between CPCI and FCI.
Results:
The HPL was successfully extracted by applying both CLAHE and fuzzy c-means algorithms. CPCI and FCI resulted in a slightly different HPL, even from the same facial region, indicating a greater percentage area of HPL in FCI than CPCI.
Conclusion:
CPCI and FCI may be utilized to differentiate HPLs that exist in different skin layers. Thus, this approach may contribute to the effective treatment of HPLs.

