Image forming apparatus and method of controlling image forming apparatus

An image forming apparatus comprising:

• a scanner configured to read an image of a document and generate image data of the image according to a reading mode;
• a storage device configured to store the image data and the reading mode that was set as a parameter of the scanner when reading the image of the document;
• a processor configured to generate 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, and store data of the first combined image in the storage device, wherein
• the processor is configured to determine 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 a reading resolution of the scanner and a second resolution indicating a resolution of the image data stored in the storage device.