1. An image processing apparatus comprising: an extracting part configured to extract feature points in each of plural images sequentially generated by an image pickup apparatus; a calculating part configured to calculate motion vectors at the feature points in each of the plural images; a clustering part configured to perform clustering processing on the motion vectors calculated at the feature points; a determining part configured to determine, among plural clusters obtained by the clustering processing, a specific cluster including a motion vector indicating motion of the image pickup apparatus; an estimation detecting part configured to detect, by using an estimation method which uses information relating to the specific cluster of a first image among the plural images, the specific cluster of a second image generated after generation of the first image; and a processing part configured to perform image stabilization processing on the second image based on the motion vector included in the specific cluster of the second image.