Fixed-Center Pan-Tilt Projector and Its Calibration Methods Ikuhisa Mitsugami Norimichi Ukita...

1
Fixed-Center Pan-Tilt Projector and Its Calibration Methods Ikuhisa Mitsugami Norimichi Ukita Ma satsugu Kidode Graduate School of Information Science Nara Institute of Science and Technology Objectives: Drawing graphics on the planar surfaces in t he environment by projectors. Precisely at where we would like it be. Without any distortions. Enable to move it freely on the planes. Even when it moves across a boundary of two planes, it should lie in the similar way to a paper poster folded a long the planes. How to accomplish it? Steerable (enable to pan and tilt) mechanism. Fixed-center pan-tilt (FC-PT) projecto r. Multiple FC-PT projectors can be used for larger sp ace. wall R relation image plane P 1 projector board light projector board light pan tilt projector screen 2 projec ted point screen 1 3D translation plane R initial orientation tangent plane Q (X, Y) another orienta tion initial center direction center direction at the orientation (u, v) u v ) tan , (tan t p ) , ( t p ) , ( t p 1 tilt axis pan axis Introduction Normal (fixed) projector Normal pan-tilt projector FC-PT projector. Implementation of FC-PT Projector Projection to One Plane Projection to Multiple Planes Experimental Results Rough estimation of projection center Precise fixing Future Works Advantages of FC-PT Projector Automatic set-up of FC-PT projectors. Cooperation with cameras. Cooperation of multiple FC-PT projectors. For display of larger graphics than the capacity of one project Correction of misalignment among the graphics of the projectors Specification Projector: PLUS VISION V3-131 Projection System: DLP Resolution: 1024*767 (XGA) Brightness: 1000 lm Contrast Ratio: 2000:1 Steerable stage Orientation accuracy: 0.002 deg Rotating speed: 10 deg/s (X, Y) (x, y) image plane P 1 wall R relation ) , ( t p image plane P 2 image plane P 1 wall R projector relation (X, Y) (x, y) wall R projector ) , ( t p image plane P 2 image plane P 1 relation corresponding area of P 1 wall R tangent plane Q FC-PT projector corresponding area of P 2 relation H wall R tangent plane Q FC-PT projector X Y Introduction of “tangent plane” Q. Image planes of all orientations can be projected on Q. As Q does not move, the relation between Q and R is fixed. Their relation H can be determined by 4 pairs of coordinates on Q and R. (horizontal view) (vertical view) tangent plane Q plane R 0 image plane inversely distorted graphic graphic to draw ' QP H ) ' , ' ( t p ) , ( ) ( ) ( gra k gra k v u ) , ( ) ( ) ( pro j pro j v u ' P ) , ( ) ( ) ( gra k gra k Y X FC-PT projector R c R m graphic G m corresponding area of R m T m : intersecti on of G m and R m center direct ion tangent plane Q S m : projecti on of T m R’ c By connectivities of multiple planes in the environment and 2D coordinate of every plane, transformations parameters between 2D coordinates of every 2 are calculated. To display graphics on planes, all we have to do are: locate the FC-PT projector anywhere we like, measure the 2D metric size of the plane, and direct the projector to 4 corners of the plane and record them. FC-PT projector can provide: 1) Easy set-up, 2) Precise display, 3) Real-time process. G c is calculated from G m by the transformation between R m and R c R c R m S m graphic G c FC-PT projector R’ m T c : intersecti on of G c and R c tangent plane Q corresponding area of R c S c : projecti on of T c center direct ion Input image to projector Projection result on the walls

Transcript of Fixed-Center Pan-Tilt Projector and Its Calibration Methods Ikuhisa Mitsugami Norimichi Ukita...

Page 1: Fixed-Center Pan-Tilt Projector and Its Calibration Methods Ikuhisa Mitsugami Norimichi Ukita Masatsugu Kidode Graduate School of Information Science Nara.

Fixed-Center Pan-Tilt Projector and Its Calibration Methods

Ikuhisa Mitsugami Norimichi Ukita Masatsugu KidodeGraduate School of Information ScienceNara Institute of Science and Technology

Objectives: Drawing graphics on the planar surfaces in the environment by projectors.

Precisely at where we would like it be.Without any distortions.Enable to move it freely on the planes.Even when it moves across a boundary of two planes, it should lie in the similar way to a paper poster folded along the planes.

How to accomplish it?Steerable (enable to pan and tilt) mechanism. “Fixed-center pan-tilt (FC-PT) projector.”Multiple FC-PT projectors can be used for larger space.

wall Rrelation

image plane P1

projector

board

lightprojector

board

light

pan

tilt

projector

screen 2

projected point

screen 13D translation

plane R

initial orientation

tangent plane Q

(X, Y)another orientation

initial center direction

center direction at the orientation

(u, v)

u v

)tan,(tan tp ),( tp

),( tp

1

tilt axis

pan axis

Introduction

Normal (fixed) projector

Normal pan-tilt projector

FC-PT projector.

Implementation of FC-PT Projector

Projection to One Plane

Projection to Multiple Planes

Experimental Results

Rough estimation of projection center

Precise fixing Future Works

Advantages of FC-PT Projector

Automatic set-up of FC-PT projectors.Cooperation with cameras.

Cooperation of multiple FC-PT projectors.For display of larger graphics than the capacity of one projector.Correction of misalignment among the graphics of the projectors.

SpecificationProjector: PLUS VISION V3-131

Projection System: DLPResolution: 1024*767 (XGA)Brightness: 1000 lmContrast Ratio: 2000:1

Steerable stageOrientation accuracy: 0.002 degRotating speed: 10 deg/s

(X, Y)(x, y)

image plane P1

wall Rrelation

),( tp

image plane P2

image plane P1

wall Rprojector relation

(X, Y)(x, y)

wall Rprojector

),( tp

image plane P2

image plane P1

relation

corresponding area of P1

wall Rtangent plane QFC-PT projector

corresponding area of P2 rela

tion Hwall R

tangent plane QFC-PT projector

XY

Introduction of “tangent plane” Q.Image planes of all orientations can be projected on Q.As Q does not move, the relation between Q and R is fixed.Their relation H can be determined by 4 pairs of coordinates on Q and R.

(horizontal view) (vertical view)

tangent plane Q plane R0

image plane

inversely distorted graphic

graphic to draw'QPH

)','( tp ),( )()( gra

kgrak vu

),( )()( proj

proj vu

'P),( )()( gra

kgrak YX

FC-PT projector

Rc

Rm

graphic Gm

corresponding area of Rm

Tm: intersection of Gm and Rm

centerdirection

tangent plane QSm: projection o

f Tm

R’c

By connectivities of multiple planes in the environment and 2D coordinate of every plane,

transformations parameters between 2D coordinates of every 2 planes are calculated.

To display graphics on planes, all we have to do are: locate the FC-PT projector anywhere we like,measure the 2D metric size of the plane, anddirect the projector to 4 corners of the plane and record them.

FC-PT projector can provide: 1) Easy set-up, 2) Precise display, 3) Real-time process.

Gc is calculated from Gm by the transformation between Rm and Rc

Rc

Rm

Sm

graphic Gc

FC-PT projector

R’m

Tc: intersection of Gc and Rc

tangent plane Q

corresponding area of Rc

Sc: projection of Tc

centerdirection

Input imageto projector

Projection resulton the walls