1. A storage medium readable by a computer, the storage medium storing a program of instructions executable by the computer to perform a function comprising: from a reading unit that reads a printed material including an image according to a reference image data, a margin, and a handwritten annotation, acquiring input image data indicating a result of reading; comparing the input image data with the reference image data; extracting handwritten annotation data representing the handwritten annotation contained in the input image data based on a result of comparing; discriminating a location of the handwritten annotation within the input image data with respect to predetermined areas within the input image data; classifying the extracted handwritten annotation data according to the location of the handwritten annotation within the input image data with respect to predetermined areas within the input image data, wherein the classifying includes determining whether or not the handwritten annotation according to the extracted handwritten annotation data includes a geometry which points to a specific place in the input image data, and when the geometry is included, the handwritten annotation data is classified as a floating type, and specific place data, which represents position information of the specific place, is generated; classifying the extracted handwritten annotation based on whether the handwritten annotation according to the extracted handwritten annotation data includes a pre-determined geometry that indicates permission or non-permission of disclosure of the handwritten annotation; and displaying the handwritten annotation, when the extracted handwritten annotation data includes the pre-determined geometry that indicates permission of disclosure of the handwritten annotation, according to the handwritten annotation data classified as the floating type on an image according to the reference image data, wherein if the location of the handwritten annotation in the input image data is within the margin, the location of the handwritten annotation according to the extracted handwritten annotation data determined as the floating type is relocated to a position within a display range of the image according to the reference image data, and the handwritten annotation is linked with the specific place according to the specific place data.