A sidewalk information generation device includes a thinning unit configured to perform thinning processing for extracting, from image data indicating an area of a sidewalk, a centerline in a width direction of the area of the sidewalk, a segmentation unit configured to perform segmentation processing for dividing the centerline extracted by the thinning unit in a longitudinal direction to generate a plurality of lines, and a vectorization unit configured to convert each of the plurality of lines generated by the segmentation unit to vector data indicating a coordinate sequence of a plurality of line segments.