1. Specialization module TTM5 Part: Collaboration Space Building Block 2 Item/NTNU October 2013. L A Rønningen

2. CollSpace2 – a realization of a collaboration space Legend: CSBB2 – CollSpace2 Building block. Space width x depth x height = 4 x 3 x 2.5 m.

3. 3 NREN Uninett Transfer Decompress Process Transfer Compress Process 60 fps –> 8.3 ms mean delay 240 fps –> 2.1 ms mean delay 30 ms 15 ms Now, Σ ≈ 90 ms Future DMP, Σ ≈ 24 ms 5 ms 10 ms DMP – Distributed Multimeda Plays Architechture 60 fps –> 8.3 ms mean delay

4. A multi-view display with a special plano- concave lens array and laser scan

5. CSBB composed of four 1/4CSBBs each of size 65 x 65 mm

6. Sparse aperture, PSF, OTF, MTF PSF = |F{aperture function}| MTF = |OTF|= |F{PSF}| = autocorrelation of aperture function MTF gives the contrast for all spatial frequencies between 0 and cut-off. An optical system without aberration is said to be diffraction limited 2

7. Real Airy disk created by passing a laser beam through a pinhole aperture (source: http://en.wikipedia.org/wiki/Airy_disk)http://en.wikipedia.org/wiki/Airy_disk

8. Sparse Apertures A sparse aperture system captures the scene radiance from several small apertures instead of one big. As with a single lens, it is important that all rays for a given scene point arrive in phase. In the Collaboration Space (CollSpace2) integrated display and camera system, RGB lasers are used to scan and show multiple views. In order to be nearly invisible and not make any conflict with the laser, the cameras have to be very small (1 mm diameter) and nearly invisible, and have to be placed on the edges of the CSBB module.

9. OTF for one circular aperture

10. Design of optimal sparse apertures The MTF – should be radially symmetric – must have no zeros before cut-off (low-pass filter) – values must be larger than the noise values – can then be restored by e. g., Wiener filter In the case of CSBB2, the sub-apertures must be placed on the edges of the laser display

11. With N circular, equal, in-phase apertures the OTF equals the MTF

12. Camera lenses as can be distributed on the boundary Legend: L – luminance camera, C – colour camera, R – right, L – left, U – up, D – down. For example, L RU denotes a luminance camera array covering the upper right space segment seen from the camera.

13. The MTF of the L RD

14. How to find the MTF by autocorrelating the aperture function Full (nearly) overlap Moved one diameter 1D, Moved 2D area 7A overlap area 1Aoverlap area 2A Moved 3D, overlap area 1A Moved 6D, no overlap (cut-off)

15. 7-aperture images of a chirp

16. CMOS and CCD sensors CMOS – Digital and analog circuits + sensor on one chip – Fast and random readout – Low power consumption – Low price CCD – Higher S/N than CMOS – Higher dynamic range

17. CollSpace2 LRGB cameras Separate Luminace (L) and color (RGB) cameras – Human perception is much more sensitive to luminance than colour -> down-sample colour in time and space – L sensors much more sensitive than RGB sensors, due to ‘Bayer’ Combining L and RGB using Photoshop – See Syllabus See separate description of lab exerciselab