Image reading apparatus, control method of image reading apparatus, and storage medium

A method comprising:

• reading an image of a document by light being emitted to the document by a light emitting unit;
• causing the reading unit to perform first reading processing for obtaining first information obtained by causing the light emitting unit to emit light with a first light amount, and second reading processing for obtaining second information obtained by causing the light emitting unit to emit light with a second light amount that is smaller than the first light amount while no document is placed at a reading position of the reading unit;
• detecting a first position and a second position as positions of a foreign matter existing at the reading position according to a difference between the first and second information;
• and
• determining, in a case where an interval between the first position and the second position is greater than a predetermined value, that a black foreign matter exists at each of the first position and the second position, and in a case where the interval between the first position and the second position is less than the predetermined value, that a white foreign matter exists between the first position and the second position.

A non-transitory computer readable storage medium for storing a computer program for controlling an apparatus, the computer program comprising:

• a code to read an image of a document, by light being emitted to the document by a light emitting unit, by a reading unit;
• a code to cause the reading unit to perform first reading processing for obtaining first information after the light emitting unit emitting light with a first light amount and to perform second reading processing for obtaining second information after the light emitting unit emitting light with a second light amount that is less than the first light amount while no document is placed at a reading position according to the reading unit;
• a code to detect a first position and a second position as positions of a foreign matter existing at the reading position according to a difference between the first and second information;
• and
• a code to determine, in a case where an interval between the first position and the second position is greater than a predetermined value, that a black foreign matter exists at each of the first position and the second position, and in a case where the interval between the first position and the second position is less than the predetermined value, that a white foreign matter exists between the first position and the second position.