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UWE Bristol Engineering showcase 2015

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Baxter Wynnes<br />

Beng(Robotics)<br />

Project Supervisor<br />

Dr Abdul Farooq<br />

Pedestrian Detection and Motion Tracking<br />

This report discusses a solution for visually detecting and tracking moving objects in real time from a stationary camera, using humans as a test case. This<br />

is achieved by using a Kalman filter to estimate the linear trajectories of single targets that have been classified from segmented moving regions in an<br />

image sequence acquired during live acquisition. The final classifier is trained using the histograms of orientated gradients (HOG) extracted from positive<br />

and negative training images sampled from the INRIA upright pedestrian database. The author trains a Support Vector Machine to recognise HOG<br />

descriptors of people. Motion is detected by using a Gaussian Mixture Model for background subtraction, and the segmented regions are classified over<br />

different scales to test for the presence of a person. The author implements the final system design and simulation in the mathematical software package<br />

MATLAB®.<br />

Project summary<br />

A solution is produced for visually detecting and<br />

tracking moving objects in real time from a stationary<br />

camera, using humans as a test case. Achieved by<br />

using a Kalman filter to estimate the linear<br />

trajectories of single targets that have been classified<br />

from segmented moving regions in an image<br />

sequence.<br />

Project Objectives<br />

Using the aid of currently available computer vision<br />

techniques explore the area of object detection and<br />

motion tracking, the final output should have to<br />

potential to serve as a sensory input for an<br />

autonomous agent.<br />

Project Conclusion<br />

A method of pedestrian detection and motion<br />

tracking has been successfully produced using<br />

MATLAB®.<br />

The system manages to successfully perform<br />

unfiltered tracking on multiple unobstructed<br />

people with non-linear motion trajectories at<br />

a range of different scales. It can also<br />

successfully estimate the linear motion<br />

trajectory of a single target under occlusion -<br />

provided that it has been seen prior to<br />

occlusion.<br />

Step 1 : Segment Moving regions<br />

Identify whether or not a moving<br />

object is present within the current<br />

frame. To detect foreground objects<br />

we must compute a difference in<br />

values between the current scene<br />

and a background model of the<br />

scene.<br />

Step 2: Classify<br />

The next step is to classify<br />

detected regions as pedestrian<br />

or non- pedestrian. A support<br />

vector machine is trained using<br />

the histogram of orientated<br />

gradients.<br />

Step 3: Predict<br />

If a pedestrian becomes occluded,<br />

use the Kalman filter to estimate<br />

the location.<br />

Step 4: Analyse tracking sequence<br />

The final tracking system can be seen to be<br />

highly accurate when detection can be made<br />

at regular intervals , but suffers from latent<br />

detections. The Kalman filter serves a good<br />

linear estimator and succeeds in smoothing<br />

the trajectory when the interval between<br />

latent detections is small .

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