Patent ID: 8115953

Claim:
An image forming apparatus comprising: an input unit through which a condition for reading first image data of a document is input; a reading unit to read the first image data under the reading condition input through the input unit; a first storage unit to store second image data based on the first image data read by the reading unit; a second storage unit to store information indicative of a relationship between the reading condition and at least one first estimated volume of the second image data to be stored in the first storage unit; a data volume estimating unit that estimates a volume of the second image data based on the reading condition and the information stored in the second storage unit to generate a second estimated data volume; and a determining unit to determine whether to read the first image data based on the second estimated data volume and a volume of third image data stored in the first storage unit; wherein a timing for reading the first image data is controlled according to a determination result by the determining unit.