Figure 2

The process of the vanishing point-based steerable filter. The process of the vanishing point-based steerable filter. (a) is the original image, and (b) is the direction map decided by the estimated vanishing point. (c) and (d) are the response image convoluted by $G_{0^{\circ }}$ and $G_{90^{\circ }}$. (e) is the result of rising (red) and falling (green) edges synthesized by (c) and (d). (f) is the final binary image of matching the rising and falling edges. (g) and (i) are the result of Sobel algorithm and Canny algorithm. (h) and (j) are the result of matching both rising edges and falling edges of (g) and (i).