VIRTUAL MUSEUM – AN IMPLEMENTATION OF A

MULTIMEDIA OBJECT-ORIENTED DATABASE

Rodrigo Filev Maia, Jorge Rady Almeida Junior

Escola Politécnica – Universidade de São Paulo (EPUSP)

Av. Prof. Luciano Gualberto, 158. trav. 3 cep:05508-900 – São Paulo- SP - Brazil

Keywords: Virtual museum, object-oriented database, multimedia content.

Abstract: This paper describes the main characteristics involved in th

e process of using multimedia content in the

Internet sites and it presents a proposal for an implementation of an object-oriented database, in order to

assist the multimedia data exigency in a dynamic website. It is described an implementation of the proposed

architecture, consisting of a virtual museum made for the Contemporary Art Museum of the USP, called

Virtual MAC, which was elected as the 3

best virtual museum of the world by INFOLAC Web 2005

(UNESCO) . The main objective of Virtual MAC is to create a virtual collection of works at art and make it

available on Internet. Our analysis shows that it is more appropriate to use the Object Oriented paradigm

instead of Relational Modelling due to the nature of the multimedia data and the structure of the dynamic

web site used for the Virtual MAC.

1 INTRODUCTION

Nowadays there are a great variety of multimedia

items, which can be inserted in a database, such as

images, audio and video files. It must also be

considered that this type of data has several

parameters which should be take into consideration

whatever may the system be, and must be stored in

the database, such as the quality of a video image or

the taxes of audio samples. The kinds of objects,

which have some special characteristics, must be

considered during the database design. The new

applications on Internet have massive use of

multimedia data, such as audio, video and several

types of animation files. Another trend on Internet is

the building of dynamic sites in order to provide a

fast way to update or change information for the

users. A difficult task that appears in this scenario is

some limitations in the relational databases that

could be used to support dynamic sites. The main

reason of the difficulties is the representation of

complex data in the relational database, such is the

multimedia data. The limitation presented in storing

and recovering complex data may increase the

complexity of the site application (Rashid, 2001). In

the case of a Virtual Museum, there is a huge

amount of multimedia data, such as videos, pictures

and animation files. It is turn not properly the use of

relational database to support the dynamic site, such

as Virtual MAC, and the use of an oriented-object

database becomes the more appropriate approach to

address a solution for the virtual museum. In order

to present the structure and considerations among

the Virtual MAC, following sections composes this

paper. The section 2 describes the relation between

an object-oriented database and the structure of web

documents, such as web pages, and it is shown why

the use of object-oriented database if a quite better

option to build the Virtual MAC, instead of to use a

relation database. The section 3 and 4 describes the

Virtual MAC and the structure of object-oriented

database, and the section 5 brings some final

remarks about this work.

2 MULTIMEDIA DATA AND

OBJECT-ORIENTED

DATABASES

Multimedia contents are presenting more importance

through time, since they represent new types of

communication through the Internet. We can say

that these multimedia data constitutes a new kind of

communication, allowing the implementation of new

communication ways. (Hacid, Declair,

Kouloumdjian, 2000).

102

Filev Maia R. and Rady Almeida Junior J. (2006).

VIRTUAL MUSEUM – AN IMPLEMENTATION OF A MULTIMEDIA OBJECT-ORIENTED DATABASE.

In Proceedings of the First International Conference on Software and Data Technologies, pages 102-107

 SciTePress

The multimedia data is defined, for the purposes

of this paper, as the content composed by text,

audio, video and graphics or any combination of

them. The multimedia data have some peculiar

characteristics like larger complexity (difficulty to

represent them in the relational model - e.g. an

electronic circuit), multi-valued and complex

structure fields (e.g. an industry plant). This leads to

the use of object-oriented databases that can

implement, in a more efficient way, such aspects,

when compared with Relational Databases. (Elmasri,

Navathe, 2003). It means that the database schemas

are designed to deal specifics data types and

application scenarios, and they do not consider a

hybrid type of data, such as multimedia. (Woelk,

1986).

The difficulty to represent these data types in the

Relational Database is the possible combination of

the elements and their representation as valid

Internet documents (Ishaq 1999). Nowadays, a web

site is composed by more than one of these types of

pages. When a dynamic web site must be built, it is

complex to represent all these page possibilities in a

relational database (Wen, et al. 2003).

Taking into consideration the implementation

methods of such complex system, it is more

appropriate to make the implementation directly in

an object-oriented database management system,

avoiding the problem of impedance mismatch. The

option of storing complex information in an Object-

Oriented Database has a clear advantage over

Relational Databases: the complex information of an

object could be better represented and its data may

be easier accessed by the user application through an

object-oriented database. The object could also be

composed by other objects, which could facilitate

the representation of more complex data. (Yu,

Meng, 1994), (Tepfenhart, Cusick, 1997). All

methods that work with the object do not need to be

implemented in the application that builds pages.

Instead of that, the application only use what it is

defined inside the database, which simplifies and

guarantees that all pages will work with the object at

the same way. This encapsulation is useful in order

to permit that any modification in one object of the

database does not damage or interfere in any other

object functionality. The approach proposed for this

work is closer than Service Oriented Architecture

(SOA) approach (MacKenzie, et. al. 2006), or even

the usual Internet programming patterns, such MVC

(Modelling, View and Control)

3 AN IMPLEMENTATION OF AN

OBJECT-ORIENTED

MULTIMEDIA DATABASE

The “Museu de Arte Contemporânea da USP”

(MAC USP) (Museum of

Contemporaneous Art of

University of São Paulo) has an outstanding

collection of around 8,000 pieces of art, including

paintings, prints, drawings, photographs, engravings,

sculptures and conceptual works, constituting a great

cultural heritage with national and international

influences. The main idea of Virtual MAC is to

associate the information technology with art,

making available all the collection that belongs to

MAC. Considering that one of the purposes of the

site is to divulge the MAC around the world, the

information in the site is displayed in three different

languages (Portuguese, Spanish and English).

The system database should contain all

significant information for each work of art. Some of

the most important kinds of media are high quality

images, besides files of video and audio. The basic

reason for the need of high quality multimedia files

is that users may need to have access to images that

allow the observation of the work’s details.

Considering the three-dimensional works, it is also

desirable to have the possibility to visualize them at

the same perspective of a real visitation.

3.1 A Proposal for an

Object-Oriented Multimedia

Database

In the Virtual MAC all pages must be dynamic

because researches from museum can need to

modify, add or even delete some information or

picture about any work of art at any time. Each one

of the work of art stored in the database has several

features related to itself and also with its

presentation in the website. One important target of

this system is presenting the world of art for

common people, and at same time provides useful

information for art specialists. The Virtual MAC

must also provide the better experience for the user

as possible. For instance, three types of images and

two types of text compose the work of art. There is

one image to be shown as an icon, one for users that

are connected on the Internet by a dial system; and

there are another rich image for ADSL, and another

for the Internet2 users. The last type of image could

have more than 10Mbytes each one, and permits to

observe minimal details of an work of art, such as

the author’s signature. The Virtual MAC has the

following types of multimedia information and tools

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103

on the Internet, which must be supported by object

oriented database:

• Information about work of art: texts with useful

information such as work of art description,

historical information, author’s life, etc;

• Work of art images: several of them were

digitalized and it is reproduced in two resolutions.

One it is for dialup and ADSL Internet

connections, and the other is for Internet 2

connections (very high quality image);

• Animations about sculptures: the three-

dimensional work of art can be view by the web

site visitor at the same angles that they could see

in the museum;

• Virtual tours and expositions: expositions can be

built and the virtual visitor can “walk inside” the

museum. He can see the work of art and select

one of them to receive more detailed information;

• Videos and audios about art and the museum:

videos and audios have three types of quality: one

for dialup connections (until 56kbps), one for

ADSL users and other to Internet 2 users (high

video and audio quality).

The table 1 presents the main requirements of

the Virtual MAC, in order to support all information

types and pages used in the web site of virtual

museum.

3.2 Involved Technologies

In order to build such complex Internet system

following the proposed requirements, it was built a

web site based on dynamic pages, which was

developed in Active Server Pages (ASP)

. The

choice of this development platform was based on

the Application Program Interfaces available for

database manufacturer. However, the same kind of

system could be developed in any other development

platform, such Java (using Struts, Java Server Faces

or any other technologies). As it was used ASP the

application server is the Internet Information Server.

It was also used a streaming server in order to

provide some videos.

The Virtual Mac database was Caché 5.0 and

one of the main reasons to choose this tool was its

availability and its development interface and some

API for Microsoft’s environment.

4 DATABASE ARCHITECTURE

The database used to implement the Virtual MAC

was an object-oriented database. There were

designed two distinct databases, the first one for the

virtual collection and the second one for the

dynamic site. In a dynamic site there are no pages

written in HTML and their contents are stored in a

database. Another characteristic is that there are no

predefined pages in a dynamic site. The HTML code

for each page is generated when requested by each

user, through their access to the site page.

One of the main advantages of this kind of

practice is to facilitate the publication of updates,

ASP – Microsoft Corporation

Table 1: Main requirements of Virtual MAC.

Object type Information Requirements Internet Requirements

Work of

art

- Name of the picture or sculpture;

- Author’s name;

- Artistic school;

- Year of the work of art production;

- Short description of the work of

art;

- Complete description of the work

of art;

- Images from the work of art (in

different resolutions);

- What image of the work of art must be

presented into website (related to the user’s

bandwidth);

- Quality and size of the image;

- The file names containing some animation

or image of the work of art;

Audio - File size;

- Description about audio content.

-The audio quality that would be used in the

website in each bandwidth;

- Audio quality and format;

- Audio location (in the hard disk);

Video - File size;

- Description about video content

-The audio quality that would be used in the

website in each bandwidth;

-Video quality and format;

-Video location (in the hard disk);

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which may improve the usability of the site, since

anyone may publish contents in the website

independently of his technical skills in web

technologies. In order to support all functionalities

of the website, it was employed an Object-Oriented

database, which demonstrated to be very suitable,

because of the complex nature of the data stored.

(Barbosa, 1992). The Figure 1 shows an example of

a work of art available at Virtual MAC The site

address is http://www.macvirtual.usp.br.

Figure 1: Example of a work of art in the Virtual MAC

collection.

4.1 Virtual MAC Database for

Work of Art

The main attributes of each work of art stored in the

object-oriented database are name, date of creation,

catalogue number, dimensions and others, justifying

the creation of an object. More than one artist might

have done one work and each artist may be the

author of one or many works. Each author has

particular characteristics, justifying another object.

This structure was applied in other components of

Virtual MAC, and results in a simplified class

diagram shown in figure 2.

The main class, which it is the “core” of the

database is called Artwork, and it is responsible by

the control of all information related to pictures,

sculptures and any other type of work of art. This

class also has methods that manipulate its

parameters, such as storing information from an

object, or modifying some parameter.

The class Artwork has some inherent classes,

which works as parameters of the class. One of these

classes is called Object_360, and it controls the

sculptures animation. It makes possible to the

Internet users round the work of art and observe

several details. The same happens with Description

class when all descriptions have the same

characteristics for any class, and the edition controls

are the same for any component of the dynamic site.

The class Picture manages all characteristics

belonging to all images of the work of art. This class

controls the quality of the image, files size and

name, and also controls what image can be used in

each type of connection (dialup, broadband or

Internet 2).

Artwork

Collection

Technic

Artistic Tendency

Picture

Artistic School

Object_360

Exposition

Description Author

1..*

1..3

0..*

Figure 2: Class Diagram of Object Oriented Database

from Virtual MAC.

The database does not copy the entire object

inside another one, when an object has other object

as its parameter. Instead, the object stores references

controlled by the Object-Oriented Database

Manager, which build the relationship between

objects. A clear advantage of this is that one object

can be used by several other objects, as it happens

with Author class. This feature of sharing objects

increase the importance of the object controls its

own parameters, in order to avoid that one object

changes some information and damage other one.

4.2 Virtual MAC Database for

Dynamic Site

The second database implemented for Virtual MAC

supports the publisher system. It maintains all data

necessary for dynamic pages generation. The

database follows the class diagram shown in figure

3.This database was implemented using the same

database management system of the work of art

database, and its main function is to store all

information from website not related to the work of

art, such as information about courses, the museum

history and museum partnerships. SiteArea is one of

the database classes containing the website areas

(expositions, virtual tour, etc.). The control data of

each specific item is stored in PageContent.

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105

The content is controlled by the object

Description, which is common to all objects, making

uniform all website contents for maintenance

purposes. In the class Event, any MAC event is

registered and controlled, and the class Agenda, is

used to date activities like expositions, workshops

and laboratories, for example. The class

AbstractPageContent stores all parameters form

class PageContent. This last one has all methods and

inherits the properties of AbstractPageContent. The

same happens with Event and AbstractEvent class,

and all inherits mechanisms are provided by the

database manager system. (DEV_APP 2002),

(Cache_Ref 2002), (Cache_Tool 2002).

4.3 The Virtual MAC Access

According to statistics collected from the Virtual

MAC website, there was a huge increase of access

since the proposed system was available. The figure

4 indicates the number of access in 2002 in which

Virtual MAC was online from October to December

and from 2003 until March 2006. In 2002 MAC had

less than 7000 access during these three months,

what it is about 2190 access per month. In 2003, the

first complete year of Virtual MAC, the number of

access was 105.610, an increase of 401,8% (based in

access per month). It may be observed that the

number of accesses continuously increases during

the years. In 2005 the number of access was

approximately 29.572 access per month, and in 2006

this number is closer than 83.437 access per month.

It reflects the robustness of the system, mainly the

database, which support and store all data consulted

by visitors, and the performance is quite appropriate,

since it has no complain about usage or lack of

resources during interaction between users and the

application.

Update

Project

Description

AbstractPageContent

Museum Staff

PageContent

SiteArea

AbstractEvent

Exposition

Course Museum Agenda

Event

0..*

Figure 3: Class Diagram from Dynamic site.

Certainly, this success (in terms of increase in

accesses) is not the directly result of the technology

used in the Virtual Mac development only, but the

cause of the success is also the page design and the

content of the museum. However, the technology

presented in this work is one of the key aspects of

the Virtual Mac success, since all information is

based on the database and the developed software.

All website tools provide great level of

interactivity and works with rich media, which

implies in quite new and robust software as well as a

system whom permits fast data recover and access.

One of the key for Virtual Mac success is the

combination of technology and rich and interesting

media, which guarantee a new kind of experience for

the Internet user.

5 CONCLUDING REMARKS AND

FUTURE WORK

The object-oriented database demonstrates to be an

interesting and powerful solution to manage

multimedia content. This type of database permits to

create more complex data structures, which can be

used directly in the application code, since it is

based on the database API. As this technique

simplifies the application code implementation, this

process was fast, once all methods that manipulate

the objects were inside the database. All pages,

independent of its location, have access to the same

classes and methods, which facilitates the use of the

information in the whole site.

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The actual database architecture is appropriate for

the actual requirements. Although the efficiency of

this architecture, it is a desire to integrate new tools

and games in the Virtual MAC website. One tool is

based in VRML (Virtual Reality Modelling

Language), which allows that any user from Internet

builds its exposition and opens it for other users.

There is a prototype of this environment, but it is not

integrated with the object-oriented database yet.

Other tools such as puzzles can be obtained from

work of art pictures and some programming in order

to create an algorithm to make the picture in small

pieces and to control the interaction with users. This

type of tool can also be developed based in the

object-oriented databases, since the pictures stored

in the system could be used in order to generate the

puzzle.

ACKNOWLEDGEMENTS

The authors thank the support of Santander Banespa,

MAC - Museu de Arte Contemporanea

(Contemporary Art Museum of the USP) and FUSP

(Fundação da Universidade de São Paulo), in the

development of this work.

REFERENCES

Barbosa, Ana Maria Tavares Bastos. (1992) “Catalogo

Geral de Obras 1963-1991”. Museu de Arte

Contemporânea da USP.

Caché Reference Material. (2002). Available on the

product CD-ROM.

Number of Ac cess

6572

105610

150783

354867

250312

50000

100000

150000

200000

250000

300000

350000

400000

2002 2003 2004 2005 2006

Figure 4: Virtual Mac – Number of accesses.

Caché Tools and Utilities. (2002). Available on the

product CD-ROM.

Developing Applications with Caché. (2002). Available on

the product CD-ROM.

Elmasri, R.; Navathe, S.B. Fundamentals of Database

Systems, 3

Edition, Addison Wesley, 2003.

Hacid, M.S.; Decleir, C.; Kouloumdjian J., (2000) “A

Database Approach for Modeling and Querying Video

Data”. In IEEE Transactions on Knowledge and Data

Engineering, September/October, p. 729-750.

Ishaq, A., (1999). “Lessons Learned Introducing an

Object-Oriented Database in the Telecom Industry”. In:

Proceedings of Technology of Object-Oriented

Languages and Systems, p. 214-223.

MacKenzie, C.M. et. al (2006) “Reference Model for

Service Oriented Architecture”. Draft 1.0, OASIS.

28pp.

Rashid, A., (2001) “A Database Evolution Approach for

Object-Oriented Databases”. In: Proceedings of IEEE

International Conference on Software Maintenance, p.

561-564.

Wen, J. et al. (2003) “A Multi-paradigm Querying

Approach for a Generic Multimedia Database

Management System”. In SIGMOD Record, v. 32 No.

1, March.

Woelk, D.; Kim, W.; Luther, W.; (1986). “An object

oriented approach to multimedia databases”. In:

Proceedings of the 1986 ACM SIGMOD international

conference on Management of data.

Tepfenhart, W.M.; Cusick, J.J. (1997). “A Unified Object

Topology”. In IEEE Software, January p. 31-35.

Yu, C.; Meng, W., (1994) “Confronting Database

Complexities”. In: IEEE Software, May. p. 6-10.

VIRTUAL MUSEUM – AN IMPLEMENTATION OF A MULTIMEDIA OBJECT-ORIENTED DATABASE

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