An image processing apparatus extracts an object area (e.g., character, picture, line drawing, and table) from an input image and acquires a metadata to be associated with the object. The image processing apparatus generates a transparent graphics description for an object area having an attribute that requires generation of the transparent graphics description, and generates an electronic document while associating the transparent graphics description with the metadata. As transparent graphics description, an arbitrary shape of graphics can be used. Accordingly, the image processing apparatus can generate electronic document data suitable for a highlight expression, which is easy for users to recognize in a search operation using a keyword to search an object included in an electronic document.