The image reader reads photoelectrically an original image including a visible image and an invisible image. The image reader includes an image reading device for reading said original image with visible light and invisible light and a detecting unit which generates correlational pixel distribution information based on visible light signals and invisible light signals read by the image reading device and detects noise components in the original image by use of said pixel distribution information. The image reading method shortens time to perform processing for washing off silver components remaining in a film upon developing an original image on the film and eliminates an influence of residual silver components remaining in an original image on a developed film by image signal processing subsequent to reading of the original image on the developed film.