1. An image forming apparatus comprising: a display section to execute display based on image data including a plurality of images; a first image processing section to generate first images respectively corresponding to the images included in the image data, to which an image process based on information of a job regarding editing and post-processing is not executed; a second image processing section to generate a second image obtained by executing the image process based on the information of the job regarding the editing and the post-processing to the image data of the first image currently displayed in the display section; and a control section to cause the display section to display the first image corresponding to the image data to which the job is set before completing the generation of the corresponding second image by the second image processing section and to change the currently displayed first image to the corresponding second image after completing the generation of the corresponding second image by the second image processing section.