1. An image capturing apparatus comprising: an image pickup system configured to take frame images including a past frame image and a current frame image; a shake detection sensor configured to detect a shake of the image capturing apparatus at the time of the current frame image, and thereby generate shake information that represents the shake, wherein the shake information includes a pitch direction component and a yaw direction component; a geometric converter configured to perform a geometric conversion process on the past frame image based on the shake information to obtain a geometric conversion image; a motion vector detector configured to detect a motion vector between the geometric conversion image and the current frame image that has not undergone the geometric conversion process, wherein the motion vector includes shake components except the pitch and yaw direction components; an image stabilization parameter calculator configured to calculate an image stabilization parameter for motion information by using the shake information and the motion vector; and a stabilized image generator configured to generate a stabilized image through a deformation process to the current frame image or a frame image generated subsequent to the current frame image by utilizing the image stabilization parameter.