An image forming apparatus includes an image forming unit configured to form a predetermined pattern image on a sheet, a notifying unit configured to provide a notification of an orientation for placing the sheet on which the predetermined pattern image is formed by the image forming unit, on a placement portion, a reading unit configured to read the sheet on a line to line basis, to generate image data, and a detection unit configured to detect a streak-shaped image extending in a direction along a predetermined edge of the sheet, by analyzing the image data generated by reading the sheet by the reading unit, wherein the notifying unit provides a notification of a placement orientation for allowing the sheet, on which the predetermined pattern image is formed, to be read on a line to line basis, the line extending in a direction along the predetermined edge.