1. An image stabilizing apparatus comprising: a motion vector calculating part that calculates a motion vector between a plurality of images including a displacement caused by a motion of an image-pickup apparatus; a shake-correction parameter calculating part that receives the motion vector as input to calculate a shake correction amount; and an image transforming part that performs geometric transformation of the image in accordance with the shake correction amount, wherein the shake-correction parameter calculating part includes: an accumulated variation amount calculating part that calculates accumulated variation amounts from an initial image of a sequence of images, the accumulated variation amounts being calculated based on image variation amounts calculated between a current image and a past image and between past images at different points of time; and a correction amount calculating part that calculates the shake correction amount based on the accumulated variation amounts, wherein the correction amount calculating part transforms the accumulated variation amounts into at least one of components of horizontal translation, vertical translation, in-plane rotation, horizontal foreshortening, and vertical foreshortening.