Image processing apparatus, image processing method, and non-transitory computer readable medium

An image processing apparatus includes a feature point extraction unit that extracts feature points which are pixels located at the corner of a region within an image and directions indicating a positional relationship of the feature points in the region, a selection unit that selects the feature point and a set of feature points corresponding to the feature point, based on a color of the feature point, a position of the feature point, and a direction in the feature point, a representative point determination unit that determines a representative point representing a region, based on the set of feature points, a vector calculation unit that calculates a vector composed of two representative points, on the basis of the representative points, and a screen line number and angle extraction unit that extracts the number of screen lines and an angle used in the image, based on a distribution of the vectors.