Help understanding Hough transform

1. How does Hough transform work?
2. What is meant by Hough transform?
3. How can Hough transform be used to identify lines?
4. How do you find the lines in an image using the Hough transform?

How does Hough transform work?

The Hough transform takes a binary edge map as input and attempts to locate edges placed as straight lines. The idea of the Hough transform is, that every edge point in the edge map is transformed to all possible lines that could pass through that point.

What is meant by Hough transform?

The Hough transform is a popular feature extraction technique that converts an image from Cartesian to polar coordinates. Any point within the image space is represented by a sinusoidal curve in the Hough space.

How can Hough transform be used to identify lines?

If two edge points lay on the same line, their corresponding cosine curves will intersect each other on a specific (ρ, θ) pair. Thus, the Hough Transform algorithm detects lines by finding the (ρ, θ) pairs that have a number of intersections larger than a certain threshold.

How do you find the lines in an image using the Hough transform?

Detect Lines in Images Using Hough

Find the edges in the image using the edge function. BW = edge(rotI,'canny'); imshow(BW); Compute the Hough transform of the binary image returned by edge . [H,theta,rho] = hough(BW);