1. An image processing apparatus for detecting a contour of an object from an image including a shot of the object, said apparatus comprising: an image input processing portion used to input the image; a feature point detection processing portion that detects plural feature points of the object from the input image; a posture estimation processing portion that estimates a rotation angle indicating a posture of the object from the detected, plural feature points; an initial parameter estimation processing portion that estimates initial parameters to detect the contour of the object from the detected, plural feature points; an initial parameter correction processing portion that corrects the estimated initial parameters using the estimated rotation angle; and a contour generation processing portion that generates the contour of the object using the corrected initial parameters.