GIS Based Studies in the Humanities and Social Sciences - Chpater 2 pdf

STAMP allows us to easily create, publish, share, and navigate pseudo-three-dimensional 3D spaces com-prised of multiple photos.. A Tool for Creating Pseudo-3D Spaces with Hyperphoto 21s

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A Tool for Creating Pseudo-3D Spaces with Hyperphoto: An Application in Ethnographic Studies

Hiroya Tanaka, Masatoshi Arikawa, Ryosuke Shibasaki, and Yuki Konagaya

CONTENTS

2.1 Introduction 19

2.2 Related Concepts 22

2.2.1 Photo Collage 22

2.2.2 Hypermedia 23

2.3 STAMP: A Tool for Hyperphoto Collage 25

2.3.1 Concepts and System Overview 25

2.3.2 STAMP-Maker 27

2.3.3 STAMP-Navigator 29

2.3.4 Visualization Options 30

2.4 An Application 30

2.5 Conclusion 32

References 33

2.1 Introduction

In the field of ethnography, researchers deal with a large number of photos

A researcher’s mission is to stay in developing countries, often in Asia or Africa, and describe their environment while sharing experiences with native people During their stay, they try to record their everyday life in detail (Konagaya, 1991; Konagaya, 1998; Konagaya, 1999) Some research-ers will stay for about one year in the target locale and take more than 100 photos per day Photos are a particularly useful medium for establishing 2713_C002.fm Page 19 Monday, September 26, 2005 7:35 AM

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20 GIS-based Studies in the Humanities and Social Sciences

a record of places, people, life, and atmosphere in a target area because they provide a rich source of information about spaces or places in the real world The main advantages of photos in such studiesare:

• Instant acquisition: An ordinary camera can be used quickly and easily

• Rich information: Far from representing abstract data, photos are genuine records of real-world phenomena

• Subjectivity: A photo often reveals not only the photographer’s target, but also the subjective point of interest (POI) of the photog-rapher

• Scalability: Photos include micrographs, landscape photos, satellite photos, and so on Photos thus enable us to examine the real world

on any spatial scale

While photos are clearly the most important medium for such studies, several problems make it difficult to effectively manage large collections

of photos These problems are related to two aspects of the way we manage photos:

• Organization and association

• Browsing and interaction

A few methods for organizing and associating photos have already been developed For example, one method is to plot locations of photos onto two-dimensional (2D) maps like a typical geographical information sys-tems (GIS)(Figure 2.1) If the location (latitude and longitude) where each photo is taken can be recorded using global-positioning system (GPS) and other technologies, we can plot locations of photos onto a map almost automatically However, such conventional methods do not enable us to sufficiently understand the relationships among photos With regard to browsing and interaction, two general approaches are usually taken — the album approach and the slide show approach (Figure 2.2) However, neither of these is essentially interactive or sufficient to describe the dynamic experiences of the photographer

In this chapter, we describe a new method for managing photos through computers We have developed and implemented a software that we call STAMP (Spatio-Temporal Association with Multiple Photos) [Tanaka (2002a), Tanaka (2002b), Tanaka (2003)] STAMP allows us to easily create, publish, share, and navigate pseudo-three-dimensional (3D) spaces com-prised of multiple photos With this software, users can create not only intensive scenes, but also extensive 3D scenes, which enable interactive and continuous navigation Furthermore, users can relive their own or other’s experiences sequentially Researchers can manage photos based on the context of the photos by using this software Our software can solve 2713_C002.fm Page 20 Monday, September 26, 2005 7:35 AM

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A Tool for Creating Pseudo-3D Spaces with Hyperphoto 21

several of the problems mentioned above and advance the use of photo applications

In the following sections, we describe two important concepts that under-lie our approach — photo collage and hypermedia In Section 2.3, we explain STAMP and discuss the characteristics of STAMP In Section 2.4,

we report on an experiment using STAMP, and then conclude in the final section

FIGURE 2.1

Photos plotted their locations onto a 2D map.

FIGURE 2.2

An album approach and a slide show approach.

Time

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2.2 Related Concepts

2.2.1 Photo Collage

Our approach is based on artistic representation through the concept of photo collage on a 2D canvas; that is, a general method of organizing and associating photos People can connect, overlap, and rotate photos on the 2D canvas to compose a single image that represents a memorable sight or event in the real world Figure 2.3 shows an example of our photo collage David Hockney, a famous artist who created so many photo collages, said that photo collage clearly reveals the photographer’s perception of the world (Hockney, 1985) David named the series of his photo collage works “Moving Focus.” This naming implies his notion about photo collage

Photo collage is an effective way to assemble multiple photos into one complete image Moreover, we can read through multiple scenarios in a single photo collage Figure 2.4 shows an example of the visual paths in our photo collage

The photo collage approach has shortcomings, though, in that it is only a static, 2D graphic representation Our proposed representation is a

pseudo-FIGURE 2.3

An example of 2D photo collage.

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3D and interactive representation, the details of which will be introduced in Section 2.3.3

2.2.2 Hypermedia

Our approach is also based on the hypermedia concept In computer science, the hypermedia concept was a remarkable discovery The World Wide Web (WWW), which most of us use daily, is based on hypermedia The hyper-media structure is very simple Only two elements, nodes and hyperlinks, are used to create hypermedia We can apply various kinds of media as nodes, such as texts, images, sounds, movies, and so on

Historically, hypermedia concept was derived from hypertext concept Simply saying, hypertext is a content network comprised of texts and hyper-links (Figures 2.5 and 2.6)

There are several views regarding hypertext (Peter, 2003) One view of hypertext technology is that it is an authoring method In other words, hypertext is a data-organization paradigm It augments raw data with a rich, semantically meaningful structure Hypertext also provides the means to create a contextfor data This viewpoint implies that the meaning of data is not inherent in the data itself, but rather resides in the structures into which the data is incorporated Data is, in itself, only useful when set into a context, structured, and reinterpreted to play a role in a particular setting Some researchers view hypertext technology as an interaction paradigm; for exam-ple, browsing as an alternative to query We can browse data by continuously

FIGURE 2.4

Visual paths in a photo collage.

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following hyperlinks between nodes Each path, which typically consists of several hyperlinks, tells us an inherent story

With the popularization of various media, such as images, sounds, and movies, the hypertext concept has been extended to the hypermedia concept Today, we can associate various kinds of media, which are not only texts but also images, sounds, and movies, by using hyperlinks Hypermedia is easy

to use for both authoring and browsing, so it has achieved worldwide accep-tance and has enabled the remarkable growth of the WWW

FIGURE 2.5

Hypertest structure based on nodes and hyperlink.

FIGURE 2.6

Hypertext network

Hyperlink

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Our STAMP incorporates the hypermedia concept Our software is based

on the hyperphoto concept, which can be considered a kind of hypermedia The details of our hyperphoto concept will be discussed in the following section

2.3 STAMP: A Tool for Hyperphoto Collage

2.3.1 Concepts and System Overview

Until now, there has been no direct linkage between the photo collage and hypermedia, discussed in Section 2.2 The former is a technique used in the field of art, while the latter is a technique used in the field of computer science However, we have found that these two techniques are similar in important respects That is, both are easy to use and enable us to create multiple scenarios from raw data through simple operations The essential difference between the two techniques is that a photo collage represents a continuous space on a 2D plane, and hypermedia is based on a discrete structure over a computer network We have tried to merge the advantages

of both the photo collage and hypermedia in a concept

We named our concept hyperphoto collage, which is a combination of photo and photo collage Hyperphoto means a photo that contains hyper-links to others Multiple hyperphotos can form hyperphoto networks, which can be considered a kind of hypermedia

In our system, users can create spatial associations between raw photos through simple operations. Spatial-hyperlink, which is an extension of ordi-nary hyperlink, is used for creating an association between two photos We will introduce the details of spatial-hyperlink in Section 2.3.2 Figure 2.7

shows the data structure of hyperphoto networks The ability to make hyper-photo networks is an authoring technique of our system

Moreover, our system automatically makes a pseudo-3D photo collage from hyperphoto and displays it (Figure 2.8) This allows us to navigate in pseudo-3D space interactively and continuously This is our browsing tech-nique We will discuss this process in detail in Section 2.3.3

We have implemented two components of STAMP: STAMP-Maker and STAMP-Navigator STAMP-Maker is an authoring tool, and STAMP-Navi-gator is a browsing tool Figure 2.9 illustrates both the flow of editing photos with the two STAMP

components and the relations among the three levels

of processing data, that is, raw photo, hyperphoto networks, and hyperphoto collage, as visualization of hyperphoto

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FIGURE 2.7

Hyperphoto networks composed of photos and spatial-hyperlinks.

FIGURE 2.8

Hyperphoto collage automatically made from hyperphoto

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2.3.2 STAMP-Maker

STAMP-Maker, one of the STAMP components, is a tool for creating pseudo-3D spaces from multiple photos The operations to associate photos are very simple A user specifies the same feature or area in two photos by drawing

a rectangle or polygon on each of the two photos In the example shown in Figure 2.10, the same building appears in two photos, and the user has drawn

a rectangle enclosing the building on each of the photos Specifying two rectangles on two photos attaches a starting anchor and an ending anchor

to create a spatial-hyperlink between the two photos A spatial-hyperlink is comprised of two areal anchors in each photo, which are a starting anchor and an ending anchor Unlike ordinary hyperlink, spatial-hyperlink enables

us to make a relationship between two partial areas in each photo

FIGURE 2.9

A flow of editing photos with stamp

FIGURE 2.10

Creating a spatial-hyperlink between two photos.

Stamp-Maker (an authoring tool)

Stamp-Navigator (a browsing tool)

Raw photos

Hyperphoto networks

Hyperphoto collage

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Thus, users can create associations between any photos, even photos taken

by different people or on different dates Users can also create additional spatial-hyperlinks on one photo Therefore, users can create many different routes for spatial navigation (Figure 2.11)

A spatial-hyperlink is basically used to specify the same feature or area in two photos to create an association regarding the spatial meaning in the real world A more advanced use, however, is to create an association between two photos taken in different places For example, the same kind of dishes may appear in two photos taken in different restaurants, and a user can create a spatial-hyperlink associating the two photos In such cases, the photos are linked based on semantic relationship over the space rather than a

spatial relationship Furthermore, STAMP-Maker also offers advance uses of spatial-hyperlinks, which represent temporal order In short, these are three types of using spatial-hyperlinks — spatial relationship, semantic relationship, and temporal relationship Their mechanisms are the same at the system level,

FIGURE 2.11

(See color insert following page 176.) Creating various routes by using spatial-hyperlinks.

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and the differences between them exist only at the application level We will introduce those differences through our example in Section 2.4

2.3.3 STAMP-Navigator

STAMP-Navigator is a browsing tool that allows people to navigate pseudo-3D spaces through a simple interface In this component, each spatial-hyperlink is associated with a geometric transformation combining translation, rotation, and distortion The transformation is defined so that

a rectangle specified in the photos at one end of a spatial-hyperlink is transformed into a corresponding rectangle specified in photos at the other end of the spatial-hyperlink This navigation system displays one focused photo and several linked photos The focused photo is placed at the center

of the display, and linked photos are placed at transformed positions Projection transformation is used for this process The focused photo is opaque, while linked photos are translucent and overlaid on the focused photo When a user selects a photo from the linked photos by directly clicking on it, the scene changes The navigation system displays a short animation that represents a smooth transition (Figure 2.12) In the transition

to the next scene, the currently focused photo fades out and the next focused photo moves to the center Simultaneously, the transparency values

of all photos are changed This animation gives the user a sense of motion toward the viewpoint of the next focused photo A photo may be linked

to more than one photo, which allows scene transitions to fork into multiple paths Thus, users can freely step forward, step backward, step sideward, rotate, translate, and zoom in/out in the pseudo-3D spaces by selecting from among candidate photos This mechanism makes great use of a human’s spatial cognition of perspective scenes STAMP-Navigator thus allows people to experience a sensation similar to walking through the real world

FIGURE 2.12

Smooth transition from one scene to the next.

A focused photo

A linked photo

A focused photo

A linked photo

Animation

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