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TitleStereo Vision Images Processing for Real-time Object Distance and Size Measurements
TagsImage Segmentation Multidimensional Signal Processing Imaging Vision Computer Vision
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International Conference on Computer and Communication Engineering (ICCCE 2012), 3-5 July 2012, Kuala Lumpur, Malaysia


978-1-4673-0479-5/12/$31.00 ©2012 IEEE


Stereo Vision Images Processing for Real-time
Object Distance and Size Measurements

Yasir M Mustafah, Rahizall Noor, Hasbullah Hasbi, Amelia Wong Azma
International Islamic University Malaysia,

P.O. Box 10, 50728, Kuala Lumpur



Abstract— Human has the ability to roughly estimate the distance
and size of an object because of the stereo vision of human’s eyes.
In this project, we proposed to utilize stereo vision system to
accurately measure the distance and size (height and width) of
object in view. Object size identification is very useful in building
systems or applications especially in autonomous system
navigation. Many recent works have started to use multiple
vision sensors or cameras for different type of application such as
3D image constructions, occlusion detection and etc. Multiple
cameras system has becoming more popular since cameras are
now very cheap and easy to deploy and utilize. The proposed
measurement system consists of object detection on the stereo
images and blob extraction and distance and size calculation and
object identification. The system also employs a fast algorithm so
that the measurement can be done in real-time. The object
measurement using stereo camera is better than object detection
using a single camera that was proposed in many previous
research works. It is much easier to calibrate and can produce a
more accurate results.

Keywords-component; stereo vision; distance measurement;
size measurement

I. INTRODUCTION

Object distance and size measurement is becoming more
essential in many applications especially in mobile autonomous
system. Information on the distance and size of the surround
objects is useful for the navigation and localization of the
mobile system. Since most of autonomous systems nowadays
are equipped with vision sensors or cameras, it is very
beneficial that the vision information is utilized to obtained
distance and size information that can be used to assist the
system.

Many research works have been done to obtain a particular
object distance from an image. Initially most of the proposed
method utilizes only a single vision sensor. For example,
Rahman et al, proposed a person to camera distance measuring
system using a single camera based on the eye-distance [1].
The distance is obtained by calculating the variation in eye-
distance in pixels with the changes in camera to person
distance. Meanwhile, Wahab et al. proposed a monocular
vision system which utilizes Hough transforms [2]. Their
system also depends on the relative size of the targeted object
to determine the distance. A different approach utilizing a
single camera was proposed by Kim et al. They proposed a
distance measurement method using a camera and a rotating
mirror [3]. A camera in front of a rotating mirror captures a

sequence of reflected images. The images are then analyzed to
obtain the distance information. The distance measurement is
based on the idea that the corresponding pixel of an object
point at a longer distance moves at a higher speed in a sequence
of images.

Recently, several research works have started to utilize
multiple vision sensors for the purpose of object distance and
size measurement. Most of the works propose to utilize stereo
configuration of cameras. One example is the work of A-Lin et
al. where they utilize stereo vision to measure the safe driving
distance of a vehicle [4]. The distance measurement is based on
the disparity of the front car in the two frame capture by the
stereo camera. Than in the work publish by Baek et al. an
improvement in the calculation of the disparity is proposed so
that a more accurate object distance can be measured [5]. In
their work they had shown that by using their method the
disparity of the object in a larger view area can be obtained.

Most of the work proposed in the literature focused only on
the distance measurement. As we have stated before, the object
size information is also very useful especially in a navigation
and localization of an autonomous system. Moreover, the size
information also can be used for a short term object
identification which is useful for autonomous system. In this
paper we proposed to utilize a method of measuring the
distance of an object as well as the size of the object using
stereo vision sensor. The method also employs a much faster
algorithm so that the measurement can be done in real-time.

II. OBJECT SIZE AND DISTANCE MEASUREMENT

The flow of the object size measurement system that we
proposed started with stereo vision image capture. Then, on
both images, a preprocessing will be applied followed by object
detection and segmentation. Finally the object distance and size
will be calculated. From the object size, object identification

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