This software first determines edges in an image and then fits lines to the edges with a provided tolerance.
This software contains edge detectors for color and gray scale images. An example demonstrating line
detection by this  software is given below.
(a)
Fig. 1. (a) A color image and (b) its edges after removal of weak edges.
(a)
(b)
Fig. 2. (a) Lines fitting to the edges of Fig. 1b. (b) Keeping only  line segments longer than a given value.
To obtain a license for this line detector, follow this link =>
(b)
Line detection
Image Registration and Fusion Systems