0
$\begingroup$

I was given this question on a job interview and think I really messed up. I was wondering how others would go about it so I could learn from this experience.

You have one image from a surveillance video located at an airport which includes line of people waiting for check-in. You have to assess if the line is big/crowded and therefore additional clerks are necessary. You can assume anything that may help your answer. What would you do?

I told them I would try to:

  1. Segment the area containing people from the rest by edge detection
  2. Use assumptions on body contour such as relative height/width to denoise unwanted edges
  3. Use color knowledge; but then they asked how to do that and I didn't know
$\endgroup$
0
$\begingroup$

Thanks for sharing your experience. It's a bit off-topic, but my my first advice for a job interview would be to check the company's technology and products. This usually helps a lot in finding answers.

In this general case of crowd surveillance in a closed place, I would check the following items first:

  • get a reference image of the empty location in order to be able to detect people's location (even inaccurate) by background subtraction. This gives a rough estimate of the queue length;
  • check if the camera is facing the line, in which case I would run a face detector to get an approximate count of people in line. This provides a second estimate;
  • if necessary, learn (from the detected faces) the skin color in the image, then again segment the image based on skin color.

There are more advanced techniques available, but I think it would be overkill here.

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.