Traffic control by digital imaging cameras - Emerging Trends in Image Processing, Computer Vision, and Pattern Recognition - page 195

• Edge Detection : Edge detection is the process for detecting meaningful discontinuities in in-
tensity values; to find places where in an image where the intensity changes rapidly. Using:
Sobel, Prewit, Roberts or Canny method. What has been used in this project is Sobel edge
detection.
• Strel Function : It is a function used to create a structuring element. It has many syntaxes;
one from them is “strel('rectangle', MN)” which was used in this project to create the plate
rectangular shape and MN represents a two-element vector of nonnegative integers ( Fig-
ure 7 ).
FIGURE 7 System flow chart.
6.1 Red-Light Violation
This part has been made by taking the absolute difference between the current inputs with a
reference one. So it could be known if the car had passed the red line.
By applying the following steps:
- Define the red-light position in the traffic light.
- Define the reference frame to compare with (when the street is empty).
- Define the frame where the violation occurred.
- Take the absolute difference between the two frames.
For that it could be known if the car had passed the red line showed in Figure 8 .
FIGURE 8 Reference of red light violation.