1. An image processing apparatus having a display device displaying a background image and a stroke image superimposed on the background image, the stroke image reproducing a stroke which is drawn by an input operation of a user, comprising: a recording unit configured to record image data of the background image and stroke data, which are related to the stroke input by the input operation, into an electronic document; a read unit configured to read the electronic document; a display unit configured to display the background image on the display device by using the image data of the background data, reproduce the stroke image by using the stroke data, and display the stroke image superimposed on the background image on the display device; and an edit unit configured to edit the stroke data in accordance with the input operation.