1. An image-processing device, comprising: a determining unit that determines image components corresponding to linked elements from an input image; an information-assigning unit that, if an adjacent end point on one side of a bounding rectangle of an adjacent second image component facing the side of the bounding rectangle of a first image component is, together with a target end point, within a predetermined range, assigns connection information to both the target end point and the adjacent end point, the target end point being defined as an end point on one side of a bounding rectangle of a first image component determined by the determining unit; an integration unit that, if the connection information has been assigned to predetermined corresponding end points of both the first image component and the second image component from among the image components determined by the determining unit, integrates the adjacent image components; a calculation unit that calculates the sum of values, the values being assigned corresponding to the connection information assigned by the information-assigning unit to each end point of the image components in an integrated image component that is composed of a plurality of image components integrated by the integration unit; and a tabular region extraction unit that, if the value calculated by the calculation unit is equal to or greater than a threshold value corresponding to the number of image components included in the integrated image component, extracts a region of the integrated image component as a tabular region.