An image composition apparatus according to the present invention comprising: an image acquiring section for acquiring first image data and second image data; a subtraction processing section for obtaining a difference value for each pixel for at least a part of the first image data and at least a part of the second image data; a filter processing section for applying filter processing based on a spatial frequency of an image to the difference value; and an image composition section for compositing at least a part of the first image data with at least a part of the second image data on the basis of an output of the filter processing.