When a document image printed by freely editing and processing image data is to be copied, the user may want to copy the edited/processed image or copy an original image before editing and processing. To meet this demand, a document image is input, and pointer information for specifying the storage location of an original image, and image process information representing whether the input image is attained by editing and processing the original image are extracted from the input image. Priority data information representing which of the input image and original image is used is obtained. When no pointer information is extracted, when the image process information represents that the original image has not been edited or processed, or when the priority data information represents the use of the input image, the input image data is converted into vector data. When the pointer information is extracted, the image process information represents that the original image has been edited and processed, and the priority data information represents the use of the original image, the original image is input on the basis of the pointer information, and an image is formed on the basis of the vector data or original image.