An exemplary OCT apparatus includes a scanner, controller, phase information generator, phase information processor. The scanner applies an OCT scan to an object using an optical scanner. The controller controls the scanner to perform a first scan that scans a cross section of the object in a first scan direction and a second scan that scans a cross section of the object in a second scan direction opposite to the first scan direction. The phase information generator generates first phase information based on first acquisition data acquired by the first scan and second phase information based on second acquisition data acquired by the second scan. The phase information processor generates composite phase information based on the first phase information and the second phase information.