抄録
In this paper, we propose a method to reduce the effect of light intensity on the extraction of skin information from real facial images. We have previously studied methods for estimating autonomic nervous activity, which is an indicator of stress, using real facial images. The results showed the possibility of assessing stress by capturing peripheral blood flow changes from the R–B values in the nasal area. However, it is possible that reflections and shadows caused by changes in the amount of light hitting the skin due to body movements, such as facial movements, could become noise. Therefore, this study proposes a weighting method to reduce the effect of light intensity caused by body movements quantitatively. We believe that this method can establish a stress evaluation method independent of the shooting environment. The results of the validation experiments using the proposed method suggest that it is possible to quantitatively reduce the effect of light intensity and evaluate peripheral blood flow conditions from actual facial images with high accuracy. This indicates the usefulness of the proposed method for stress evaluation.