An image erasing apparatus for erasing an image printed on a sheet is known. The image erasing apparatus includes an erasing unit that performs an erasing process, for example, heat process on a sheet on which an image is printed with an erasable color material to erase a color of an image on the sheet or to make a color of the color material forming the image transparent.
A user visually determines a level regarding whether to erase the image printed on the sheet before erasing the image using the erasing unit. The level regarding whether to erase the image refers to a level regarding whether erase of the image may be erased without restrictions.
The image erasing apparatus includes an image reading unit which reads the image of the sheet before erasing the image using the erasing unit, and a monitor which displays the read image before erasing the image using the erasing unit. The user views the image displayed on the monitor to determine the level regarding whether to erase the image.
If the user determines that a image to be erased is highly confidential in its contents and requires permission from a person who has predetermined authority in order to erase the image, the user may judge that the image to be erased is an image having a high level regarding whether to erase the image. If the user determines that an image to be erased is a brief note and is not required to check the contents of the image in order to erase the image, the user may judge that the image to be erased is an image at a low level regarding whether to erase the image. The user judges such a level regarding whether to erase an image for every sheet.
However, the level regarding whether to erase the image is visually judged by the user so that an erroneous judgment may be made. Since the user judges the level regarding whether to erase an image for every sheet, it is difficult to continuously erase images printed on a plurality of sheets so that it takes a long time to erase the images. Further, as the image reading unit is also required, the cost is increased for the image reading unit. It is burdensome to visually judge even an image of a low level regarding whether to erase an image.