Image processing apparatus, image processing method, and storage medium

An image processing method of an image processing apparatus that generates an output image by deforming an input image by coordinate transformation, comprising:

• a divisor calculation step of calculating a minimum value and a maximum value of a divisor, used in division operation of coordinate transformation, based on coordinate information of a pixel constituting the input image;
• a coefficient calculation step of, based on a relation between a divisor and an error in division operation, obtaining a range of the divisor in a way that a result of the division operation becomes equal to or smaller than an allowable error, and calculating a normalization parameter by dividing a minimum value of the range by the minimum value of the divisor calculated in the divisor calculation step;
• a parameter adjustment step of calculating an adjustment parameter, used in the coordinate transformation, by multiplying an input parameter by the normalization parameter, and outputting the adjustment parameter;
• and
• an image deformation processing step of performing transformation processing of the coordinate information using the adjustment parameter, and outputting a result of the transformation processing.