Obstacle detection device

An obstacle detecting device, comprising:

• an image converting portion for converting, into a circular cylindrical image, an image captured by a camera installed on a vehicle;
• a detection subject candidate image detecting portion for detecting, through pattern matching, a detection subject candidate image based on the circular cylindrical image;
• an optical flow calculating portion for calculating an optical flow based on the detection subject candidate image;
• an outlier removing portion for removing an optical flow that is inferred, based on the optical flow, not to be a detection subject;
• a TTC calculating portion for calculating a time-to-collision (TTC) based on an optical flow that remains after removal by the outlier removing portion;
• a tracking portion for calculating a region of the detection subject on the circular cylindrical image by tracking the detection subject candidate image in relation to a subsequent circular cylindrical image based on the optical flow;
• and
• a collision evaluating portion for determining whether or not there is the risk of collision between the vehicle and the detection subject, based on the TTC, wherein:
• the optical flow calculating portion calculates the optical flow based on the detection subject candidate image and the region.