An image processing apparatus comprising: a calculation section configured to obtain filtering coefficients for each of a plurality of sample points, each sample point being located in one of a plurality of first areas of an image, the image being partitioned into the plurality of first areas, the image being further partitioned into a plurality of second areas which are different from the plurality of first areas, one of the plurality of second areas being a target second area which is enclosed by the plurality of sample points, calculate a convoluted image of the target second area for each of the plurality of sample points, using the filtering coefficients obtained for the corresponding one of the sample points; an interpolation section configured to move, in each convoluted image of the target second area, a pixel positioned at a target point to the pixel position of the respective sample point of the convoluted image of the target second area, and interpolate a pixel at the target point in the target second area using the pixels moved to the positions of the sample points, by bilinear interpolation; characterized in that the image processing apparatus further comprises: a resolution analyzing section configured to analyze resolution degradation of an image at least in two directions, the image capturing a plurality of objects, each of the objects having a wedge-shaped radial pattern and to analyze the resolution degradation of each object in two perpendicular directions; and a filter data determining section configured to, for each object in the image, adjust a weight coefficient of a filter parameter in a direction having lower resolution than the perpendicular direction based on an analysis result by the resolution analyzing section, for the image of each object compensated by filters determined with a defocus function of the image, determine filter data for each object including the adjusted weight coefficient so that a difference in resolution between the two directions is minimized, and calculate a filter for each object based on the filter data, wherein the size of each first area is the size of each object and each first area contains an entire wedge-shaped radial pattern. a calculation section configured to obtain filtering coefficients for each of a plurality of sample points, each sample point being located in one of a plurality of first areas of an image, the image being partitioned into the plurality of first areas, the image being further partitioned into a plurality of second areas which are different from the plurality of first areas, one of the plurality of second areas being a target second area which is enclosed by the plurality of sample points, calculate a convoluted image of the target second area for each of the plurality of sample points, using the filtering coefficients obtained for the corresponding one of the sample points; an interpolation section configured to move, in each convoluted image of the target second area, a pixel positioned at a target point to the pixel position of the respective sample point of the convoluted image of the target second area, and interpolate a pixel at the target point in the target second area using the pixels moved to the positions of the sample points, by bilinear interpolation; characterized in that the image processing apparatus further comprises: a resolution analyzing section configured to analyze resolution degradation of an image at least in two directions, the image capturing a plurality of objects, each of the objects having a wedge-shaped radial pattern and to analyze the resolution degradation of each object in two perpendicular directions; and a filter data determining section configured to, for each object in the image, adjust a weight coefficient of a filter parameter in a direction having lower resolution than the perpendicular direction based on an analysis result by the resolution analyzing section, for the image of each object compensated by filters determined with a defocus function of the image, determine filter data for each object including the adjusted weight coefficient so that a difference in resolution between the two directions is minimized, and calculate a filter for each object based on the filter data, wherein the size of each first area is the size of each object and each first area contains an entire wedge-shaped radial pattern. a resolution analyzing section configured to analyze resolution degradation of an image at least in two directions, the image capturing a plurality of objects, each of the objects having a wedge-shaped radial pattern and to analyze the resolution degradation of each object in two perpendicular directions; and a filter data determining section configured to, for each object in the image, adjust a weight coefficient of a filter parameter in a direction having lower resolution than the perpendicular direction based on an analysis result by the resolution analyzing section, for the image of each object compensated by filters determined with a defocus function of the image, determine filter data for each object including the adjusted weight coefficient so that a difference in resolution between the two directions is minimized, and calculate a filter for each object based on the filter data, wherein the size of each first area is the size of each object and each first area contains an entire wedge-shaped radial pattern.