To suppress misclassification of structures contained in an image. [Solution] The present invention is provided with: a filtering unit (32) that calculates a Hessian matrix by performing filtering on an image using a second order partial derivative of a solid spherical function； and an evaluation unit (30) that evaluates structures contained in the image using the eigenvector and eigenvalue of the Hessian matrix. The filtering unit (32) is provided with a correction unit (33) that calculates a first order partial derivative vector by performing filtering using the first order partial derivative of a solid spherical function having the same radius as the radius of a solid sphere in the image and using the value resulting from projecting the first order partial derivative vector in the direction of the eigenvector performs correction negating one response wave among response waves represented in two positions symmetrically separated from the center of the solid sphere of the second order partial derivative in each direction of the function representing the solid sphere.
