1. An image processing apparatus, comprising: an inputting device inputting a multilevel image; a stroke extracting device extracting a plurality of stroke regions from the multilevel image, and generating a binary image of the plurality of stroke regions; a feature extracting device extracting a feature amount based on an attribute of a different pixel included in a neighboring region of a target pixel by using each pixel in each of the plurality of stroke regions as the target pixel; and a separating device separating pixels belonging to a target stroke region from the binary image of the plurality of stroke regions by using the extracted feature amount of each pixel, and generating a binary image of the target stroke region.