LASER GAME

1
LASER GAME
2

• INTRODUCTION (Kayvan)
• THEORY (Johan)
• DSP (Eugenio)
• PC (Johannes)
• Demonstration (in the lab, by Nicola)

Now speaking Kayvan
LEFT
3

• Gaming is one of the major industries that pushes
  image processing to its limits.
• Complex and flexible games
• Implement cool features
• Research new idea or significant improvement of
  an old one
• Lack of game specific research

Now speaking Kayvan
LEFT
4

• Design and implement a Laser Game
• Create moving targets
• User shall hit it with a laser pointer
• A webcam that captures a picture
• Detect hits and generate sounds
• Welcome to the new improved DUCK
  HUNT

Now speaking Kayvan
SHOTS
5

• Exploding computations320x240 76800 pixels, 20
  fps ? 1.5 miljon iterations.
• Smart and compact algorithms
• Use the a prioriWe control whats on the screen.
  Asume that the laser is white.Do not put bright
  objects in the game.
• What color to useRGB, Grayscale, One RGB
  component?

Now speaking Johan
SHOTS
6

• Detection algorithm
• if thresltimg(n)-img(n-1), then laser
• if thresltimg(n)-img(n-1), then if
  lthresltimg(n), then laser
• ref(n)0.93ref(n-1)0.07img(n) if
  thresltimg(n)-ref(n), then if lthresltimg(n),
  then laser

Now speaking Johan
SHOTS
7

• Transforming the image

Now speaking Johan
SHOTS
8

• Numerical solution.
• Over determined system, SVD.
• Precisely determined system. Null vector.
• Using the corners.

Now speaking Johan
SHOTS
9

• evm6x_hpi_write() and evm6x_hpi_read()
• Structure at know address
• - values to read
• - pointers to write
• pragma DATA_SECTION()

Now speaking Eugenio
SHOTS
10

• 320x240x8b 76.8 KB
• But we want to use the 64KB IDM!!!
• Solution pipelining
• Reference image SBSRAM (discarded pipelining to
  IDM with DMA).

Now speaking Eugenio
SHOTS
11

• Load buffers from PC into memory.
• DMA transfers in background.
• Long or shorts buffers?

Now speaking Eugenio
SHOTS
12

• After initializing the audio and some variables
• Ready_flag is polled all the time.
• When a task is finished
• - Ready_flag IDLE
• - message sent to PC.

Now speaking Eugenio
SHOTS
13
The PC application consists of three different
parts

• Capture video from the web cam
• Communication with the DSP board
• The game!!

Now speaking Johannes
SHOTS
14
Web cam

• Fast access to the video frames
• Use DirectShow, a component of the Microsoft
  DirectX 9 library
• DirectShow is very complex and competent,we only
  use two filters
• Source and SampleGrabber filters

Now speaking Johannes
SHOTS
15
How to draw the duck behind the tree
OR
AND
Now speaking Johannes
SHOTS
16
System delay

• The time it takes for something to be captured by
  the web cam (1 or 2 frames 40-80 ms).
• Processing time in the DSP ( 40-55 ms).
• Solution Use a circular buffer with the 10
  previous positions of each duck.

Now speaking Johannes
SHOTS
17
Logical part of the Game
Proceed()
Now speaking Johannes
SHOTS
18

• Project members
• Kayvan
• Nicola
• Johannes
• Johan
• Eugenio
• Sponsors
• Special thanks to