1. A document type recognition apparatus comprising: a memory having computer-readable instructions stored thereon; and at least one processor communicatively coupled to the memory and configured to execute the computer-readable instructions to separate an input image into a character region and a pattern region, the separation including generating a signal indicative of an edge region based on an amount of edge; perform smoothing processing to remove halftone dots of a particular number of lines or greater in the pattern region; generate an enhanced image by performing edge enhancement processing based on the amount of edge on an edge portion of the character region after the smoothing processing has been performed; create a density histogram of the enhanced image while excluding a pixel corresponding to the signal from the enhanced image when the signal indicates that the edge region is active; and recognize a document type of the input image and a presence of a hollow character, the document type being recognized by utilizing the density histogram, and the presence of the hollow character being recognized based on the exclusion of the pixel.