Image processing system, image scanning system, non-transitory computer readable medium storing program, and image processing method

A non-transitory computer readable medium storing a program for causing a computer to execute a process comprising:

• respectively obtaining provisional positions of edges on both sides of a document in a main scanning direction from a preset reference position, from image information obtained by scanning a first surface of the document;
• respectively obtaining provisional positions of edges on both sides of the document in the main scanning direction from the reference position, from image information obtained by scanning a second surface of the document;
• and
• respectively comparing the provisional positions of the corresponding edges of the document in the main scanning direction and determining that there is an erroneous detection in the provisional positions of the edges in a case where the provisional positions of the corresponding edges are different from each other.

An image processing method comprising:

• respectively obtaining provisional positions of edges on both sides of a document in a main scanning direction from a preset reference position, from image information obtained by scanning a first surface of the document;
• respectively obtaining provisional positions of edges on both sides of the document in the main scanning direction from the reference position, from image information obtained by scanning a second surface of the document;
• and
• respectively comparing the provisional positions of the corresponding edges of the document in the main scanning direction and determining that there is an erroneous detection in the provisional positions of the edges in a case where the provisional positions of the corresponding edges are different from each other.