1. The Initiative Experiments for Utilizing Real Cards in Online Trading Card Game
Jong-Hyoun Kim and Teresa Cho
Department of Gameware
Kaywon School of Art & Design
125 Naeson-dong, Euwang, Republic of Korea
{hyoun, teresa}@kaywon.ac.kr
Abstract— Current virtual game interfaces can’t comprehend between virtual game space and our real behavior, we
our metaphor, can’t reflect on our natural behavior aspect, carried out an experiment on seamless gaming between 3D
can’t make us immerse into a game, and makes a barrier virtual game space and our real behavioral space as applying
between virtual game space and our real behavior. It is very real card interface into an online Trading Card Game (TCG)
challenging issue to use real objects tightly related to human-
games.
being’s behaviors or reactions for interacting with game
applications. Interactive AR interfaces may augment users’ The remainder of this paper is organized as follows.
perception of the real world by adding virtual information to it. Section 2 compares with existing related work. Section 3
In addition, users’ interaction with the system may be introduces my experiment about new TCG game interface
augmented, making the computer as seamlessly as possible. We system including a gaming flow. Finally, we conclude with
attempted an experiment on camera-based interface for online a note on the current status of my project and future work.
TCG game application which emits excellence of AR. This
experiment uses real TCG cards which are recognized by II. RELATED WORK
texture based AR algorithm. These initiative experiments not
only guarantee the consistency between the game-player’s A variety of research efforts have recently explored
behaviors and the gaming environment, but also make real and computationally augmented interfaces that emphasize human
virtual world seamless. This consistency increases friendliness interaction using marker, markerless or sensor-based
and immersion to a game as well as the ability of bodily interface.
sensation for a game. This new interface takes the results of
A. Sensor-based interface
human-being's behaviors as input event, and will open the new
field of digital interfaces for forthcoming ubiquitous Affective Computing Group at MIT is making an effort
computing. for sensing/recognizing/understanding/synthesizing the
human behavior patterns. This group discussed the use of
Keywords; TCG game interface, camera-based, markerless, biometric sensors with wearable computers. Such sensors
immersion to game. Augmeted Reality allow for new interactions between the wearable and the
wearer, which they based upon affect detection, prediction,
I. INTRODUCTION1 and synthesis [3].
Basically AR systems support the coexistence of real B. Camera-based marker interface
elements and computer generated synthetic ones in the same Differently to the Affective Computing Group’s sensor-
environment [1]. Nowadays, this kind of user interface has based approach, other some approaches use camera-based
obtained more attention due to the fact that it allows users technology. MagicMouse allows the user to operate within
performing tasks in a more intuitive, efficient and effective both 2D and 3D environments by simply moving and
way. Interactive AR interfaces may augment users’ rotating their fist. Position and rotation around the X, Y and
perception of the real world by adding virtual information to Z-axes are supported, allowing full six degree of freedom
it. In addition, users’ interaction with the system may be input. This is achieved by having the user wear a glove, to
augmented, making the computer as seamlessly as possible, which is attached a square marker. Translation and rotation
by exploring the use of real objects for interaction with the of the hand is tracked by a camera attached to the computer,
application. Therefore, they may augment actions that users using the ARToolKit software library [4]. Rohs uses visual
are capable to perform in the real world, both in quantity of codes for several interaction tasks with camera-equipped cell
tasks performed and their quality [2]. phones [5]. His IPARLA Project designed a new 3-DOF
Especially game system needs the use of real objects for interface adapted to the characteristics of handheld
interaction with its application to reflect on user’s natural computers. This interface tracks the movement of a target
that the user holds behind the screen by analyzing the video
behavior aspect as well as to make user immerse into the
stream of the handheld computer camera. The position of the
game. As one of experimental approach to break a barrio
target is directly inferred from the color codes that are
1
printed on it using an efficient algorithm [6]. There was a
This research is supported by Ministry of Knowledge Economy and trial to apply markers as a offline game tool into online dice
Electronics and Telecommunications Research Institute(ETRI) in the
Technology Innovation Program 2009 game application [7].

2. C. Marker-less interface
Markerless AR systems use natural features instead of
fiducial markers in order to perform tracking. Therefore,
there are no ambient intrusive markers that are not really part
of the world. Furthermore, markerless AR counts on
specialized and robust trackers. Another advantage is the
possibility of extracting from the surroundings characteristic
information that may later be used by the AR system for
other purposes.
In the past, edge and optical flow based methods for
model based tracking were combined, since they are
complementary with respect to the usage of spatial and
temporal information [8]. More recently, [9] used both edges
and optical flow without the need of a known motion model,
which is the case of most AR applications. Texture based
feature extraction and optical flow tracking were also joined
together in a multithreaded manner in [10]. Another
approach to speed up the tracking is to use only a subset of
the template pixels for pose calculation, which can be
selected previously in an offline phase. [11] proposed the
Selective Pixel Integration, where the pixels to be used are
randomly selected from the ones that contain more texture
information. [12] selected the most adequate pixels to the
linear approximation performed in [13]. [14] do the same for
the IC and ESM methods.
Nevertheless above outstanding research works, no one
of these approaches has applied real objects which are used
as a gaming tool in the real field. We think our experiment is
the first trial to apply real objects into online game
applications.
III. NEW TCG GAME INTERFACE
A. Online TCG Figure 1. Recognizing any pose and tilted
In addition to actual physical card games, trading card
games have also been developed that are played over the The recognition system has been implemented under
Internet and LAN lines. Instead of receiving physical cards, a OpenCV2.0 and tested using Point Gray’s Flea2 IEEE 1394b
player establishes a virtual collection that exists only as a set compatible camera.
of data stored on a server. Such cards can be purchased or
traded within this environment. Titles include online versions
of games that originated as physical TCGs, as well as games
that exist solely online. The first online CCGs were Sanctum
and Chron X.
For applying real TCG card into online TCG game, we
used two real TCG dinosaur cards as experimental purpose,
one is Albertosaurus and the other is Spectal Majungasaurus.
B. Card Recognition System
The recognition system based on keypoint extraction
algorithm [15] can recognize any pose of planar image and
can be calibrated to recognize the tilted image within 20
degree above and below both, so the user does not have any
difficulties or does not need to train it to make the card be Figure 2. Before recognizeing the card
recognized by a camera. The system can be scaled by the
distance of images from a camera. Figure 1 shows you how Figure 2 and Figure 3 and 4 shows before and after
much recognize planar and declined image in any pose. recognizing the specific cards respectively. As shown in
Figure 5 and 6, after detecting the card the annotating

3. information (name, value of rock-paper-scissors. figure of
power, et cetera) of the card is displayed on the top-left
corner of a screen.
Figure 3. After recognizeing the card
Figure 5. New TCG System Flow
IV. CONCLUSION AND FUTURE WORK
To work with missing intelligence and aesthetics,
interfaces must understand our metaphors, solicit
information on its own, acquire experiences, talk to a wide
variety of people, improve over time, and be intelligent in
context. As part of this exploration, we attempted an
experiment on camera-based and marker-less interface for
online TCG game application. We carried out an experiment
on seamless gaming between TCG virtual game space and
our real behavioral space as applying real card interface into
Figure 4. After recognizeing the second card online TCG games. This new game interface guarantees the
consistency between the game-player’s behaviors and the
C. New TCG System Flow gaming environment. This consistency increases friendliness
and immersion to a game as well as the ability of bodily
We use the whole structures of origin TCG games as is. sensation for a game. This new interface takes the results of
In other words this means that we may apply The Card human-being's behaviors as input event, and will open the
Recognition System to origin TCG game application new field of digital interfaces for forthcoming ubiquitous
independently as like plug-in. The system communicates to computing.
TCG client program through RPC message passing
mechanism. In addition to origin system we just attached a We are still working on following areas.
Map Table to catch Card ID from detected the image. So, as • Motion or gesture interface as networked new game
soon as the Recognition System detects an image the system interface
send Image ID to TCG Client. TCG Client gets Card ID
• Social games thru n-screen
using the Image ID and sends it to TCG Server. The overall
system flow is depicted in Figure 5. • Interaction mechanism to make real and virtual
world seamless

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