Decoloring apparatus and method

A decoloring apparatus, comprising:

• a sheet conveying unit;
• a scanner configured to scan an image on a sheet conveyed by the sheet conveying unit;
• a decoloring unit configured to decolor the image on the sheet conveyed through the sheet conveying unit, wherein the decoloring unit is positioned downstream of the scanner in a sheet conveying direction, and a distance along the sheet conveying direction between the scanner and the decoloring unit is shorter than a length of a first predetermined sheet size and longer than a length of a second predetermined sheet size;
• a user interface that includes a sheet size setting section configured to receive an input for setting a size of the sheet to be conveyed by the conveying unit;
• and
• a controller configured to:
• determine whether the sheet conveyed by the sheet conveying unit is the first predetermined sheet size or the second predetermined sheet size based on the input received in the sheet size setting section, and
• perform a mode limiting process if the sheet size is determined to be the first predetermined sheet size, wherein the mode limiting process is a processing which prevents:
• scanning the image at a resolution higher than a predetermined resolution, or
• if a resolution higher than the predetermined resolution is already set for scanning the image, decoloring the image.