1. An image correction apparatus comprising: a processor configured to: compute an absolute difference value between corresponding pixels in a first and a second image; determine, for each pixel contained in a filter region defined around an attention pixel on the first image, a weighting coefficient so that the weighting coefficient increases as the absolute difference value of the pixel increases; compute a motion metric value indicating a likelihood of the presence of a moving object by summing values obtained by multiplying the absolute difference value of each pixel contained in the filter region by the weighting coefficient computed for the pixel; compute a combining ratio of the second image to the first image so that the combining ratio decreases as the motion metric value becomes larger; and produce a corrected image by combining the value of the attention pixel in the first image with the value of the corresponding pixel in the second image in accordance with the combining ratio computed for the attention pixel and by taking the combined value as the value of the corresponding pixel in the corrected image.