Visualization of Cosmetic Foundation Application Status Based on Facial Color Fluctuations Induced by Heartbeat

Applying cosmetic foundation is a fundamental aspect of makeup; however, achieving uniform coverage can be challenging. If an uneven application could be visually and intuitively recognized, beginners could apply the foundation more effectively. This study proposes a noninvasive method to visualize foundation coverage by leveraging the phenomenon in which the foundation attenuates subtle skin color fluctuations caused by heartbeats. Unlike conventional methods that rely solely on visible-color contrast, our approach captures heartbeat-induced variations. This method was validated through two experiments. Experiment 1 confirmed that the proposed technique could consistently detect foundation-applied areas across a diverse group of participants. Experiment 2 demonstrated that the degree of signal suppression, and thus, the visualization contrast, increased with the amount of foundation applied, even when the foundation color closely matched the natural skin tone. In addition, the use of reference signals from the palm yielded comparable results, underscoring the practical versatility of this method.