How to calculate vehicle speed ?

[ramdas]

hello everyone ,i am doing my project in image processing.i am taking video of car moving on the road and taking video frames of the same.

i want to calculate speed of vehicle.using frame rate i can calculate the time elapsed by vehicle to cover some distance. but i have one difficulty, As the vehicle goes away its size goes down also we can’t use linear scale to compute the distance .for this can anybody help me for distance computation?
or is there any other way to calculate speed vehicle using image processing?
i am doing my coding using MATLAB software.
i am adding images ,so that u can get an idea about it..thank u

 

[Simon Bridge]

If you know the dimensions of the vehicle, then you can use the apparent size on the screen to tell you it's distance from the camera in each frame.

If you have a parallel distance scale in the shot (say a row of fence posts with a known separation) you can use that to help you work out the distance covered.

 

[ramdas]

but sir,nonlinear scale is the biggest problem here.

If you know the dimensions of the vehicle, then you can use the apparent size on the screen to tell you it's distance from the camera in each frame.

If you have a parallel distance scale in the shot (say a row of fence posts with a known separation) you can use that to help you work out the distance covered.

but sir,nonlinear scale is the biggest problem here...

 

[Simon Bridge]

Why is that a problem ... if you know the dimensions and geometry of, at least, some of the objects in the frame?

Presumably you also know the properties of the camera - i.e. does the camera move about, or is it stationary?
What sort of lens is used? How high is the camera POV?

Is there something regularly spaced in the frame?

You have to use data from outside the picture to be able to analyse the picture.

 

[rezeew]

I would recommend using a combination of techniques to accurately calculate the speed of the vehicle in your project. One approach could be using the frame rate and time elapsed, as you mentioned, to estimate the distance traveled by the vehicle. However, as you mentioned, the change in size of the vehicle in the video frames can make this calculation challenging.

To overcome this difficulty, you could use image processing techniques to track specific features of the vehicle, such as its wheels or license plate, as it moves through the video frames. By tracking these features, you can accurately measure the distance traveled by the vehicle and use this information to calculate its speed.

Another approach could be using multiple cameras to capture the vehicle from different angles and then using triangulation techniques to calculate its speed. This method can also help overcome the issue of the changing size of the vehicle in the video frames.

Additionally, you could also consider using radar or lidar technology to directly measure the speed of the vehicle. These technologies use electromagnetic waves to detect the motion of the vehicle and can provide more accurate and direct measurements of its speed.

In conclusion, there are various methods and techniques that can be used to calculate the speed of a vehicle in an image processing project. I would recommend exploring different approaches and choosing the one that best suits your project and provides the most accurate results.