1. An image capturing apparatus that has a three-dimensional grid data table, comprising: a holding unit configured to hold a matrix coefficient which is a basis of the three-dimensional grid data table, and editing data for editing grid point data of the three-dimensional grid data table; a calculating unit configured to calculate the grid point data of the three-dimensional grid data table by performing a matrix operation using the matrix coefficient; an editing unit configured to edit the grid point data of the three-dimensional grid data table calculated by the calculating unit, based on the editing data; and a processing unit configured to process image data acquired by image capture, using the three-dimensional grid data table edited by the editing unit.