A method of controlling an image forming apparatus including a scanner configured to read an image of a document and generate image data of the image according to a reading mode and storage device storing the image data and the reading mode that was set as a parameter of the scanner when reading the image of the document, the method comprising:
- generating a first combined image that includes the image of the document and a reading direction image that indicates a reading direction of the scanner and has a shape indicating the reading mode;
- determining a position where the reading direction image is to be disposed relative to the image of document in the first combined image and a size of the reading direction image in the first combined image, based on a first resolution indicating reading resolution of the scanner and a second resolution indicating a resolution of the image data stored in the storage device;
- and
- storing data of the first combined image in the storage device.