Activity 2: Hough Transform

The Hough transform is a feature extraction methods used in image analysis to find arbitrary shapes such as lines, circles, ellipses, etc. In this report, Hough transform is implemented in Matlab 7 and is used to fine lines in the image shown in Figure 1.

Figure 1. Original Image.

The original image is converted to graycale (see Figure 2).

Figure 2. Grayscale Image.

The edge function is the used to determine the outline of the grayscale image (see Figure 3).

Figure 3. Edge Detected Image.

The hough function is performed to determine the accumulator matrix of r and θ (see Figure 4). The equations of lines are determined from peaks of the accumulator matrix (white circles in Figure 4).

Figure 4. Hough Transform.

An overlay of the lines and the original image is shown in Figure 5.

Figure 5. Original Image with found Lines (colored blue).

I give myself a grade of 10 for this activity.

Reference:

[1] M. Soriano, "A - Hough Transform," 2009.