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Wild Dreams for Cameras
               Jack Tumblin
          Northwestern University
          jet@cs.northwestern.edu

From May 24 Panel Discussion on cameras at
             Symposium on
   Computational Photography & Video
            May 23-25, 2005
                      Definitions
Visual Appearance: What we think we see.
      (Consciously-available estimates of our surroundings,
       made from the light reaching our eyes)


Picture: A ‘container’ for visual appearance.
      (something we make to hold what we see,
      or what would like to see)


Image: A copy of light intensities.
      (Just one kind of picture, made by copying a scaled map of
      scene light intensities as a lens might)
 “Machine-Readable” Images?

          Scene
          Light
          Intensities

scene                   „Pixel values‟
                        (scene intensity? display intensity?
                        perceived intensity? ‘blackness/whiteness’ ?)

          Display
          Light
          Intensities


display
                    Digital Images
PHYSICAL                                          PERCEIVED
3D Scene                                               Scene
light sources,
                 Rendering                    Vision   light sources,
       BRDFs,                                          BRDFs,
       shapes,                                         shapes,
    positions,      Image           Display            positions,
  movements,        I(x,y,λ,t)      RGB(x,y,tn)        movements,
            …                                          …
Eyepoint                                               Eyepoint
   position,                                           position,
  movement,              Exposure’ or                  movement,
  projection,           Tone Mapping                   projection,
           …                                           …
                 „Digital Pictures?‟
PHYSICAL                                       PERCEIVED
3D Scene                                   Vision Scene
light sources,
                 Rendering Something              light sources,
       BRDFs,                                       BRDFs,
       shapes,
                           Else?                    shapes,
    positions,      Image                           positions,
  movements,        I(x,y,λ,t)                      movements,
            …                                       …
Eyepoint                         Display            Eyepoint
   position,                                        position,
  movement,
                                 RGB(x,y,tn)        movement,
  projection,                                       projection,
           …                                        …
Williams 1998: „Inflated Silhouettes‟
   2D Photo




                           Silhouette‘Inflate’ Depth Symmetry
    http://graphics.stanford.edu/workshops/ibr98/#Schedule%20of%20sessions
    Williams`98: „Inflated Silhouettes‟

                          Not bad! How can we do better?




•   http://graphics.stanford.edu/workshops/ibr98/#Schedule%20of%20sessions
Polynomial Texture Maps

                         Store just 6
                         coefficients
                        at each pixel,
                        get Interactive
                         re-lighting...



                            A Mostly
                           2-D Method



                     Malzbender, HPlabs 2001
 3D: Try image + other dimensions

• Halle: Multiple Viewpoint Rendering (SIGG98)
                           http://web.media.mit.edu/~halazar/sig98/halle98.pdf
               Oh et. al, 2001: 2D3D
• Manually Guided—7 Hours!
• ? Would a more varied for camera pose help?
 http://graphics.lcs.mit.edu/ibedit/ibedit_s2001_cameraReady.pdf
        Bixels: Picture Samples With
        Embedded Sharp Boundaries



Bixels (bilinear)




Pixels (bilinear)

   Jack Tumblin and Prasun Choudhury   Northwestern University, Evanston IL, USA
Results: boundary=depth discontinuity
      (Source data courtesy Ramesh Raskar, MERL)

             Source                                Boundaries
           (1100x800)                               (50x65)
Results: boundary=depth discontinuity
      (Source data courtesy Ramesh Raskar, MERL)


                 Pixels
                  (bilinear)
                  50x65




                                Bixels
                                 (bilinear)
                                 50x65

				
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