Abstract: When executing super-resolution processing, both reduction in necessary memory capacity and generation of high-resolution image data having a desired image quality are achieved. This invention provides an image forming method in an image forming apparatus capable of executing super-resolution processing using a plurality of low-resolution image data to generate high-resolution image data. The method includes steps of acquiring a plurality of low-resolution image data, selecting image data to be deleted from the plurality of acquired image data on the basis of spatial frequency information or color information of each image data, deleting the selected image data, and storing, as image data used in the super-resolution processing, remaining image data which are not deleted among the plurality of image data.

Abstract: In order to determine the image quality of an encoded image in consideration of the printing characteristic of an output apparatus (e.g., a copying machine and a printer), the image forming apparatus has an intermediate formation unit for forming dots that are based on dot data making up an encoded image on an intermediate transfer body, and a decision unit for deciding whether the encoded image should be formed on a sheet or not based on the density of the dots formed on the intermediate transfer body by the intermediate formation unit.

Abstract: The measured density value of a printer at the time is compared with the density measured value at the time of adjusting a copy-forgery-inhibited pattern density, and the fluctuation amount of the output density of the printer from the copy-forgery-inhibited pattern density adjustment time until the time is calculated. It is judged whether the calculated density fluctuation amount exceeds a density region (the threshold of density fluctuation amount) which becomes effective as the copy-forgery-inhibited pattern image. When the density fluctuation amount exceeds the threshold of the density fluctuation amount, the user is notified that the density of the copy-forgery-inhibited pattern image may have inappropriate density as the copy-forgery-inhibited pattern image by the density fluctuation. Thereby, the user can check whether the present copy-forgery-inhibited pattern image is appropriate.