To obtain a high resolution frame wherein picture quality deterioration is suppressed regardless of a motion of a subject included in the frame when obtaining one high-resolution frame from a plurality of frames sampled from motion image data.

A patch divided into one or more rectangular regions is disposed in each of the plurality of frames FrN, FrN+1, the patch is moved and/or deformed to estimate the corresponding relationship of the frames, coordinates of the frame FrN+1 are transformed on the basis of the estimated corresponding relationship, and a correlative value of this frame and the frame FrN is calculated. The number of divided regions in the patch is increased for one stage to similarly calculate the correlative value. A quantity of changes between the two correlative values is calculated and compared with a threshold value and until the quantity of the changes becomes less than or equal to the threshold value, the number of divided regions is increased to similarly calculate the quantity of changes. On the basis of the corresponding relationship estimated with the smaller number of divided regions between the two numbers of divided regions in the two correlative values wherein the quantity of changes less than or equal to the threshold value is calculated, a synthetic frame FrG is prepared from the frames FrN, FrN+1.