A disclosed image processing apparatus enables input of various documents, addition of various types of embedded information, and implementation of various behaviors associated with embedded information detection results. Information embedded in input document data is detected, and an image processing associated with a detection result is carried out. The image processing apparatus includes a document input mechanism, an embedded information analysis mechanism, a behavior determination mechanism, a document output mechanism, and an image management mechanism. In one embodiment, an interface via which the document input mechanism and the embedded information analysis mechanism are connected, and another interface via which the document input mechanism and the image management mechanism are connected are fixed, so that the document input mechanism can be replaced with a new document input mechanism that inherits from those fixed interfaces, without affecting the other mechanisms.