Document reading apparatus and method determining document size based on input width and length overlapping background area

A method performed by a document reading apparatus, the method comprising:

• receiving an input of a document size including a width and a length through an input device;
• upon receipt of the input of the document size, scanning, through a scanner, an area specified based on a maximum scan width and the input length and generating a first image corresponding to the scanned area;
• generating a second image by removing a part of the first image so that a width of the second image is equal to or greater than the input width;
• detecting a background area or a non-background area in the second image;
• determine whether or not the input document size is appropriate based on whether or not all sides of an area specified based on the input width and length overlap the background area or none of the sides overlaps the non-background area on the second image;
• and
• when the input document size is appropriate, outputting a third image after removing the background area or extracting the non-background area from the second image.

A document reading apparatus comprising:

• a scanner;
• an input device configured to receive an input of a document size including a width and a length;
• a sensor configured to detect the document size of a document to be scanned;
• and
• a processor configured to
• determine whether or not the detected document size is equal to or less than the input document size,
• when the detected document size is equal to or less than the input document size, control the scanner to scan an area specified based on a maximum scan width and the input length and generate a first image corresponding to the scanned area;
• generate a second image by removing a part of the first image so that a width of the second image is equal to or greater than the input width;
• detect a background area or a non-background area in the second image;
• determine whether or not the input document size is appropriate based on whether or not all sides of an area specified based on the input width and length overlap the background area or none of the sides overlaps the non-background area on the second image;
• and
• when the input document size is appropriate, output a third image in which the background area is removed or the non-background area is extracted from the second image.