1. An image processing apparatus, comprising: a feature value calculation unit configured to calculate, as feature values, a polarity related to gradation of a skin image and a scale indicating image areas each having a pixel value that is similar to each other and that are different from surroundings of the image areas; and a feature section extraction unit configured to extract a feature section of the skin image on a basis of the feature values calculated by the feature value calculation unit such that the feature section is extracted when the polarity calculated by the feature value calculation unit has a predetermined polarity and the scale calculated by the feature value calculation unit has a predetermined scale value.