Tennis Real Play: an Interactive Tennis Game with Models from Real Videos

TENNIS REAL PLAY

: AN

INTERACTIVE T

ENNIS

GAME WITH

MODELS

FROM REAL VIDEOS

J UI - H S I N

LA I E

T AL . ,

N T U

A C M MM 2

0 1 1

THE IDEA

THE GOAL

THE CHALLENGES1.Player Database

- Auto Video Analysis- Auto Clip Collection

2.Player Rendering- Realtime Clip Editing- Player Strategy Analysis

3.The Game System- Background/Foreground Rendering- Realtime Processing

THE CHALLENGES1.Player Database

- Auto Video Analysis- Auto Clip Collection

2.Player Rendering- Realtime Clip Editing- Player Strategy Analysis

3.The Game System- Background/Foreground Rendering- Realtime Processing

PLAYER DB: FOREGROUND SEGMENTATION

PROBLEM: THE FIGURES ARE NOT IN THE SAME SIZE…

SOLUTION: FIDUCIAL COORDINATEFiducial (adj.) 基準的

(m0~m7: homography parameters, can be determined by trigonometrics)

PLAYER DB: HIT STATISTICSJui-Hsin Lai et al., “Tennis Video 2.0: A New Presentation of Sports Videos with Content Separation and Rendering”, JVCI 2011

1. Forehand volley2. Backhand volley3. Forehand stroke4. Backhand stroke5. Drop shot

PLAYER DB: BEHAVIOR MODEL

• The final piece of the DB that combines other pieces

• Players speed, hit trajectory, reaction time…etc.

• Can create ‘virtual ’matches between players (like fantasy baseball!)

kcir:In other words, the gamer actually plays minor role in this ‘game’.Whether a player can catch up (speed/direction); how does one choose to hit (force/angle), these are pre-determined.

THE CHALLENGES1.Player Database

- Auto Video Analysis- Auto Clip Collection

2.Player Rendering- Realtime Clip Editing- Player Strategy Analysis

3.The Game System- Background/Foreground Rendering- Realtime Processing

PLAYER RENDERING: CLIP SELECTIONIf the player decides (how?) to go from point A to point B:

The system automatically choose the “suitable” clips and seam them together.

Suitable: 1. shortens the distance 2. runs along the path 3. min # of clips

FROM “MOTION” TO “HIT”

Shape/texture similarity between the frame of the clip

The Player DB

kcir:So the swing of the gamer is meaningless.What only matters is the timing of swing.

FROM “MOTION” TO “HIT”In order to look good:

They want to use “view morphing” in between the transitionPROBLEM: YOU NEED

‘LABELS’ BEFORE YOU CAN MORPHSolution: [JCV09] and [JCV04] on

Auto Labeling for morphing

THE CHALLENGES1.Player Database

- Auto Video Analysis- Auto Clip Collection

2.Player Rendering- Realtime Clip Editing- Player Strategy Analysis

3.The Game System- Background/Foreground Rendering- Realtime Processing

TO CONSTRUCT 3D FROM 2D

3D GAMING (FUTURE WORK)

EVALUATION• Computation Analysis• Prediction of Game Result

- Virtual Match• Subjective Evaluation

- Compares to Wii and xbox- Interactivity- Immersive Experience

COMPUTATION ANALYSISIntel i7 2.6 GHz CPU with 4GB RAMRendering resolution: 720 x 480

=> Frame rate: 30 fps (standard mpeg1 requirement)

Basis

You can offline-computed these two

PREDICTION OF GAME RESULT

SUBJECTIVE EXPERIMENTS20 undergrads5-point scoring system

Q1. InteractionQ2. Immersive ExperienceQ3. InterestingQ4. Innovative application (huh?)Q5. Willing to play TRP after watching videos?

SUBJECTIVE EXP: COMPARES TO OTHERSParticipants played TRP, Wii tennis, and TP3 xbox

Q6. Entertainment levelsQ7. Realism of visual effectsQ8. Interactiveness (didn't you just ask this in Q1?)Q9. Preference

RESULTS

Using Wii as the comparison basis (score=3)

Q1. InteractionQ2. Immersive ExperienceQ3. InterestingQ4. Innovative application (huh?)Q5. Willing to play TRP after watching

videos?Q6. Entertainment levelsQ7. Realism of visual effectsQ8. InteractivenessQ9. Preference

PUBLIC DEMO

People are asking: “How can I get this feature on my own TV?”

CONCLUSION1. The first work to integrate video-based

rendering and interactive sports game running in realtime

2. Without motion capture system, construct game from video without much human assistance

3. Game results can reflect the match results in real world and predict match results

COMMENTS1. The value of this work is its auto process of video->game,

which includes:- video analysis- auto editing of the clips- realtime rendering- computational complexity to overcome with

2. The game itself, although put in the title, is just a bonus3. How can this be better than Wii !?!?!?

- gamer cannot control how they hit. The hitting result is determined by the player DB. (Williams always wins)- gamer don't have to chase the ball. The player will instantly know where to go. (this is cheating!)- You will always win if you know which player to pick….And you call this FUN? Poor consumers