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; wherein the plural clusters obtained by the clustering processing include a cluster including the motion vector for a still object and a cluster including the motion vector for a moving object, the still and moving objects being in an image pickup area of the image pickup apparatus, and wherein the determining part determines the cluster including the motion vector for the still object as the specific cluster.