An image processing apparatus executes acquiring, on a first image having a pattern having first areas and second areas that have a different color from the first areas, center position of the pattern where the first areas and the second areas cross, acquiring boundary positions between the first and second area, converting the first image to a second image having its image distortion corrected by using the center position and the boundary positions, acquiring, by scanning on the second image, expectation values which are areas including the point where the first and second areas cross excluding the center position, acquiring a intersection position of the intersection on the second image based on the expectation values, acquiring the center position and the positions on the first image corresponding to the intersection position by inverting the second image to the first image, determining the points corresponding to the acquired positions as features.