Apparatus for estimating movement information

A method of calculating an estimation value of movement information of a mobile body based on information from a camera mounted on the mobile body, the method comprising the steps of:

• (a) extracting feature points from frame images input from the camera;
• (b) calculating an optical flow indicating movements of the feature points between a current frame image and a previous frame image;
• and
• (c) calculating the estimation value based on the optical flow, wherein
• the step (c) switches a calculation method of the estimation value based on at least one of (i) a speed of the mobile body, (ii) a number of the feature points extracted by the step (a), and (iii) feature amounts indicating uniqueness of the feature points.

An abnormality detection method that detects an abnormality of a camera to be mounted on a mobile body, the method comprising the steps of:

• (a) extracting feature points from frame images input from the camera;
• (b) calculating an optical flow indicating movements of the feature points between a current frame image and a previous frame image;
• (c) calculating an estimation value based on the optical flow;
• and
• (d) determining a presence or absence of the abnormality of the camera, wherein
• when a speed of the mobile body is higher than a predetermined speed, the step (c) calculates the estimation value by a first calculation method based on the feature points whose feature amounts are larger than a first threshold value, and
• when the speed of the mobile body is equal to or lower than the predetermined speed, the step (c) calculates the estimation value by a second calculation method based on the feature points whose feature amounts are larger than a second threshold value smaller than the first threshold value.