Integrated speed limit detection and recognition from real-time video

Here we propose a complete system for robust detection and recognition of the current speed sign restrictions from a moving road vehicle. This approach includes the detection and recognition of both numerical limit and national limit (cancellation) signs with the addition of automatic vehicle turn detection. The system utilizes both RANSAC-based colour-shape detection of speed limit signs and neural network based recognition whilst turn analysis relies on an optic flow based method. As primary detection is based on a robust colour and shape detection methodology this results in a real-time algorithm that is invariant to variable road conditions. The integration of both limit, cancellation and vehicle turn detection within the bounds of real-time system performance represents an advance on prior work within this field.