Abstract

Ray files offer a very accurate description of the optical characteristics of a light source. This is essential whenever optical components are positioned in close proximity (near-field) of the light source in order to perform accurate ray tracing simulations. However, a ray file does not allow for a direct simulation of the spatial luminance distribution, i.e. luminance map, by off-the-shelf ray tracers. Simulating luminance maps of light sources or luminaires is especially important in general lighting in order to predict their general perception when viewed by the observer, and more specific, the perception of glare of luminaires having a non-uniform luminance distribution. To enable the simulation of luminance maps while maintaining the high accuracy offered by a ray file, a sampling method is presented. To validate the approach, near-field goniophotometer measurements of two planar light sources were performed. From these measurement data, ray files were extracted to which the sampling method was applied in order to obtain a set of surface sources. This approach was validated by comparing measured luminance images with simulated luminance images. A good agreement was found, validating the presented method.

© 2013 Optical Society of America

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References

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  1. R. J. Koshel, “Lit appearance modeling of illumination systems,” Proc. SPIE4768, 65–73 (2002).
    [CrossRef]
  2. W. Kim, H. T. Ahn, and J. T. Kim, “A first approach to discomfort glare in the presence of non-uniform luminance,” Build. Environ.43(11), 1953–1960 (2008).
    [CrossRef]
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    [CrossRef]
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  9. M. López, K. Bredemeier, N. Rohrbeck, C. Véron, F. Schmidt, and A. Sperling, “LED near-field goniophotometer at PTB,” Metrologia49(2), S141 (2012).
    [CrossRef]
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    [CrossRef]
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    [CrossRef]
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    [CrossRef]
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    [CrossRef]
  15. TracePro®, http://lambdares.com/ .
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    [CrossRef]
  18. J.P. Lewis, “Fast template matching,” Vision interface, 120–123 (1995).
  19. V. Di Gesù and V. Starovoitov, “Distance-based functions for image comparison,” Pattern Recognit. Lett.20(2), 207–214 (1999).
    [CrossRef]
  20. 3M Vikuiti Brightness Enhancement Film, http://www.3m.com/ .
  21. C. C. Sun, T. X. Lee, S. H. Ma, Y. L. Lee, and S. M. Huang, “Precise optical modeling for LED lighting verified by cross correlation in the midfield region,” Opt. Lett.31(14), 2193–2195 (2006).
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2012 (2)

J. Muschaweck, “Optical design using luminance in ray data sets,” Proc. SPIE8485, 84850P, 84850P-6 (2012).
[CrossRef]

M. López, K. Bredemeier, N. Rohrbeck, C. Véron, F. Schmidt, and A. Sperling, “LED near-field goniophotometer at PTB,” Metrologia49(2), S141 (2012).
[CrossRef]

2011 (2)

2010 (1)

J. Audenaert, G. Durinck, F. Vandeghinste, G. Deconinck, and P. Hanselaer, “Feasibility study of a brute-force ray tracing approach to obtain luminance maps of luminaires modeled with ray files,” Proc. SPIE7717, 77170L, 77170L-11 (2010).
[CrossRef]

2008 (4)

A. Mas, I. Martín, and G. Patow, “Compression and importance sampling of near-field light sources,” Comput. Graph. Forum27(8), 2013–2027 (2008).
[CrossRef]

C. Hoelen, H. Borel, J. de Graaf, M. Keuper, M. Lankhorst, C. Mutter, L. Waumans, and R. Wegh, “Remote phosphor LED modules for general illumination – towards 200 lm/W general lighting LED light sources,” Proc. SPIE7058, 70580M, 70580M-10 (2008).
[CrossRef]

W. Kim, H. T. Ahn, and J. T. Kim, “A first approach to discomfort glare in the presence of non-uniform luminance,” Build. Environ.43(11), 1953–1960 (2008).
[CrossRef]

Y. Nakamura, “Method of discomfort glare estimation applicable to a wide range of source sizes -glare estimation system based on luminance image,” Light and Engineering16(1), 84–88 (2008).

2007 (2)

W. T. Chien, C. C. Sun, and I. Moreno, “Precise optical model of multi-chip white LEDs,” Opt. Express15(12), 7572–7577 (2007).
[CrossRef] [PubMed]

I. Ashdown and M. Salsbury, “A near-field goniospectroradiometer for LED measurements,” Proc. SPIE6342, 634215, 634215-11 (2007).
[CrossRef]

2006 (2)

C. C. Sun, T. X. Lee, S. H. Ma, Y. L. Lee, and S. M. Huang, “Precise optical modeling for LED lighting verified by cross correlation in the midfield region,” Opt. Lett.31(14), 2193–2195 (2006).
[CrossRef] [PubMed]

K. Teppei, A. Daisuke, I. Takashi, M. Takayoshi, T. Masahiro, and I. Masami, “Discomfort glare caused by white LED light sources,” J. Light Visual Environment30(2), 95–103 (2006).
[CrossRef]

2002 (1)

R. J. Koshel, “Lit appearance modeling of illumination systems,” Proc. SPIE4768, 65–73 (2002).
[CrossRef]

1999 (1)

V. Di Gesù and V. Starovoitov, “Distance-based functions for image comparison,” Pattern Recognit. Lett.20(2), 207–214 (1999).
[CrossRef]

Ahn, H. T.

W. Kim, H. T. Ahn, and J. T. Kim, “A first approach to discomfort glare in the presence of non-uniform luminance,” Build. Environ.43(11), 1953–1960 (2008).
[CrossRef]

Ashdown, I.

I. Ashdown and M. Salsbury, “A near-field goniospectroradiometer for LED measurements,” Proc. SPIE6342, 634215, 634215-11 (2007).
[CrossRef]

Audenaert, J.

J. Audenaert, G. Durinck, F. Vandeghinste, G. Deconinck, and P. Hanselaer, “Feasibility study of a brute-force ray tracing approach to obtain luminance maps of luminaires modeled with ray files,” Proc. SPIE7717, 77170L, 77170L-11 (2010).
[CrossRef]

Borel, H.

C. Hoelen, H. Borel, J. de Graaf, M. Keuper, M. Lankhorst, C. Mutter, L. Waumans, and R. Wegh, “Remote phosphor LED modules for general illumination – towards 200 lm/W general lighting LED light sources,” Proc. SPIE7058, 70580M, 70580M-10 (2008).
[CrossRef]

Bredemeier, K.

M. López, K. Bredemeier, N. Rohrbeck, C. Véron, F. Schmidt, and A. Sperling, “LED near-field goniophotometer at PTB,” Metrologia49(2), S141 (2012).
[CrossRef]

Chien, W. T.

Daisuke, A.

K. Teppei, A. Daisuke, I. Takashi, M. Takayoshi, T. Masahiro, and I. Masami, “Discomfort glare caused by white LED light sources,” J. Light Visual Environment30(2), 95–103 (2006).
[CrossRef]

de Graaf, J.

C. Hoelen, H. Borel, J. de Graaf, M. Keuper, M. Lankhorst, C. Mutter, L. Waumans, and R. Wegh, “Remote phosphor LED modules for general illumination – towards 200 lm/W general lighting LED light sources,” Proc. SPIE7058, 70580M, 70580M-10 (2008).
[CrossRef]

Deconinck, G.

J. Audenaert, G. Durinck, F. Vandeghinste, G. Deconinck, and P. Hanselaer, “Feasibility study of a brute-force ray tracing approach to obtain luminance maps of luminaires modeled with ray files,” Proc. SPIE7717, 77170L, 77170L-11 (2010).
[CrossRef]

Di Gesù, V.

V. Di Gesù and V. Starovoitov, “Distance-based functions for image comparison,” Pattern Recognit. Lett.20(2), 207–214 (1999).
[CrossRef]

Durinck, G.

J. Audenaert, G. Durinck, F. Vandeghinste, G. Deconinck, and P. Hanselaer, “Feasibility study of a brute-force ray tracing approach to obtain luminance maps of luminaires modeled with ray files,” Proc. SPIE7717, 77170L, 77170L-11 (2010).
[CrossRef]

Gadegaard, J.

Hanselaer, P.

J. Audenaert, G. Durinck, F. Vandeghinste, G. Deconinck, and P. Hanselaer, “Feasibility study of a brute-force ray tracing approach to obtain luminance maps of luminaires modeled with ray files,” Proc. SPIE7717, 77170L, 77170L-11 (2010).
[CrossRef]

Hoelen, C.

C. Hoelen, H. Borel, J. de Graaf, M. Keuper, M. Lankhorst, C. Mutter, L. Waumans, and R. Wegh, “Remote phosphor LED modules for general illumination – towards 200 lm/W general lighting LED light sources,” Proc. SPIE7058, 70580M, 70580M-10 (2008).
[CrossRef]

Huang, S. M.

Kari, T.

Keuper, M.

C. Hoelen, H. Borel, J. de Graaf, M. Keuper, M. Lankhorst, C. Mutter, L. Waumans, and R. Wegh, “Remote phosphor LED modules for general illumination – towards 200 lm/W general lighting LED light sources,” Proc. SPIE7058, 70580M, 70580M-10 (2008).
[CrossRef]

Kim, J. T.

W. Kim, H. T. Ahn, and J. T. Kim, “A first approach to discomfort glare in the presence of non-uniform luminance,” Build. Environ.43(11), 1953–1960 (2008).
[CrossRef]

Kim, W.

W. Kim, H. T. Ahn, and J. T. Kim, “A first approach to discomfort glare in the presence of non-uniform luminance,” Build. Environ.43(11), 1953–1960 (2008).
[CrossRef]

Koshel, R. J.

R. J. Koshel, “Lit appearance modeling of illumination systems,” Proc. SPIE4768, 65–73 (2002).
[CrossRef]

Lankhorst, M.

C. Hoelen, H. Borel, J. de Graaf, M. Keuper, M. Lankhorst, C. Mutter, L. Waumans, and R. Wegh, “Remote phosphor LED modules for general illumination – towards 200 lm/W general lighting LED light sources,” Proc. SPIE7058, 70580M, 70580M-10 (2008).
[CrossRef]

Lee, T. X.

Lee, Y. L.

López, M.

M. López, K. Bredemeier, N. Rohrbeck, C. Véron, F. Schmidt, and A. Sperling, “LED near-field goniophotometer at PTB,” Metrologia49(2), S141 (2012).
[CrossRef]

Ma, S. H.

Martín, I.

A. Mas, I. Martín, and G. Patow, “Compression and importance sampling of near-field light sources,” Comput. Graph. Forum27(8), 2013–2027 (2008).
[CrossRef]

Mas, A.

A. Mas, I. Martín, and G. Patow, “Compression and importance sampling of near-field light sources,” Comput. Graph. Forum27(8), 2013–2027 (2008).
[CrossRef]

Masahiro, T.

K. Teppei, A. Daisuke, I. Takashi, M. Takayoshi, T. Masahiro, and I. Masami, “Discomfort glare caused by white LED light sources,” J. Light Visual Environment30(2), 95–103 (2006).
[CrossRef]

Masami, I.

K. Teppei, A. Daisuke, I. Takashi, M. Takayoshi, T. Masahiro, and I. Masami, “Discomfort glare caused by white LED light sources,” J. Light Visual Environment30(2), 95–103 (2006).
[CrossRef]

Moreno, I.

Muschaweck, J.

J. Muschaweck, “Optical design using luminance in ray data sets,” Proc. SPIE8485, 84850P, 84850P-6 (2012).
[CrossRef]

J. Muschaweck, “What's in a ray set: moving towards a unified ray set format,” Proc. SPIE8170, 81700N, 81700N-7 (2011).
[CrossRef]

Mutter, C.

C. Hoelen, H. Borel, J. de Graaf, M. Keuper, M. Lankhorst, C. Mutter, L. Waumans, and R. Wegh, “Remote phosphor LED modules for general illumination – towards 200 lm/W general lighting LED light sources,” Proc. SPIE7058, 70580M, 70580M-10 (2008).
[CrossRef]

Nakamura, Y.

Y. Nakamura, “Method of discomfort glare estimation applicable to a wide range of source sizes -glare estimation system based on luminance image,” Light and Engineering16(1), 84–88 (2008).

Patow, G.

A. Mas, I. Martín, and G. Patow, “Compression and importance sampling of near-field light sources,” Comput. Graph. Forum27(8), 2013–2027 (2008).
[CrossRef]

Pedersen, K.

Pedersen, T. G.

Rohrbeck, N.

M. López, K. Bredemeier, N. Rohrbeck, C. Véron, F. Schmidt, and A. Sperling, “LED near-field goniophotometer at PTB,” Metrologia49(2), S141 (2012).
[CrossRef]

Salsbury, M.

I. Ashdown and M. Salsbury, “A near-field goniospectroradiometer for LED measurements,” Proc. SPIE6342, 634215, 634215-11 (2007).
[CrossRef]

Schmidt, F.

M. López, K. Bredemeier, N. Rohrbeck, C. Véron, F. Schmidt, and A. Sperling, “LED near-field goniophotometer at PTB,” Metrologia49(2), S141 (2012).
[CrossRef]

Søndergaard, T.

Sperling, A.

M. López, K. Bredemeier, N. Rohrbeck, C. Véron, F. Schmidt, and A. Sperling, “LED near-field goniophotometer at PTB,” Metrologia49(2), S141 (2012).
[CrossRef]

Starovoitov, V.

V. Di Gesù and V. Starovoitov, “Distance-based functions for image comparison,” Pattern Recognit. Lett.20(2), 207–214 (1999).
[CrossRef]

Sun, C. C.

Takashi, I.

K. Teppei, A. Daisuke, I. Takashi, M. Takayoshi, T. Masahiro, and I. Masami, “Discomfort glare caused by white LED light sources,” J. Light Visual Environment30(2), 95–103 (2006).
[CrossRef]

Takayoshi, M.

K. Teppei, A. Daisuke, I. Takashi, M. Takayoshi, T. Masahiro, and I. Masami, “Discomfort glare caused by white LED light sources,” J. Light Visual Environment30(2), 95–103 (2006).
[CrossRef]

Teppei, K.

K. Teppei, A. Daisuke, I. Takashi, M. Takayoshi, T. Masahiro, and I. Masami, “Discomfort glare caused by white LED light sources,” J. Light Visual Environment30(2), 95–103 (2006).
[CrossRef]

Vandeghinste, F.

J. Audenaert, G. Durinck, F. Vandeghinste, G. Deconinck, and P. Hanselaer, “Feasibility study of a brute-force ray tracing approach to obtain luminance maps of luminaires modeled with ray files,” Proc. SPIE7717, 77170L, 77170L-11 (2010).
[CrossRef]

Véron, C.

M. López, K. Bredemeier, N. Rohrbeck, C. Véron, F. Schmidt, and A. Sperling, “LED near-field goniophotometer at PTB,” Metrologia49(2), S141 (2012).
[CrossRef]

Waumans, L.

C. Hoelen, H. Borel, J. de Graaf, M. Keuper, M. Lankhorst, C. Mutter, L. Waumans, and R. Wegh, “Remote phosphor LED modules for general illumination – towards 200 lm/W general lighting LED light sources,” Proc. SPIE7058, 70580M, 70580M-10 (2008).
[CrossRef]

Wegh, R.

C. Hoelen, H. Borel, J. de Graaf, M. Keuper, M. Lankhorst, C. Mutter, L. Waumans, and R. Wegh, “Remote phosphor LED modules for general illumination – towards 200 lm/W general lighting LED light sources,” Proc. SPIE7058, 70580M, 70580M-10 (2008).
[CrossRef]

Build. Environ. (1)

W. Kim, H. T. Ahn, and J. T. Kim, “A first approach to discomfort glare in the presence of non-uniform luminance,” Build. Environ.43(11), 1953–1960 (2008).
[CrossRef]

Comput. Graph. Forum (1)

A. Mas, I. Martín, and G. Patow, “Compression and importance sampling of near-field light sources,” Comput. Graph. Forum27(8), 2013–2027 (2008).
[CrossRef]

J. Light Visual Environment (1)

K. Teppei, A. Daisuke, I. Takashi, M. Takayoshi, T. Masahiro, and I. Masami, “Discomfort glare caused by white LED light sources,” J. Light Visual Environment30(2), 95–103 (2006).
[CrossRef]

Light and Engineering (1)

Y. Nakamura, “Method of discomfort glare estimation applicable to a wide range of source sizes -glare estimation system based on luminance image,” Light and Engineering16(1), 84–88 (2008).

Metrologia (1)

M. López, K. Bredemeier, N. Rohrbeck, C. Véron, F. Schmidt, and A. Sperling, “LED near-field goniophotometer at PTB,” Metrologia49(2), S141 (2012).
[CrossRef]

Opt. Express (2)

Opt. Lett. (1)

Pattern Recognit. Lett. (1)

V. Di Gesù and V. Starovoitov, “Distance-based functions for image comparison,” Pattern Recognit. Lett.20(2), 207–214 (1999).
[CrossRef]

Proc. SPIE (6)

C. Hoelen, H. Borel, J. de Graaf, M. Keuper, M. Lankhorst, C. Mutter, L. Waumans, and R. Wegh, “Remote phosphor LED modules for general illumination – towards 200 lm/W general lighting LED light sources,” Proc. SPIE7058, 70580M, 70580M-10 (2008).
[CrossRef]

I. Ashdown and M. Salsbury, “A near-field goniospectroradiometer for LED measurements,” Proc. SPIE6342, 634215, 634215-11 (2007).
[CrossRef]

J. Muschaweck, “What's in a ray set: moving towards a unified ray set format,” Proc. SPIE8170, 81700N, 81700N-7 (2011).
[CrossRef]

J. Muschaweck, “Optical design using luminance in ray data sets,” Proc. SPIE8485, 84850P, 84850P-6 (2012).
[CrossRef]

J. Audenaert, G. Durinck, F. Vandeghinste, G. Deconinck, and P. Hanselaer, “Feasibility study of a brute-force ray tracing approach to obtain luminance maps of luminaires modeled with ray files,” Proc. SPIE7717, 77170L, 77170L-11 (2010).
[CrossRef]

R. J. Koshel, “Lit appearance modeling of illumination systems,” Proc. SPIE4768, 65–73 (2002).
[CrossRef]

Other (7)

TracePro®, http://lambdares.com/ .

X. S. M. Xicato, http://www.xicato.com .

K. Bredemeier, R. Poschmann, and F. Schmidt, “Development of luminous objects with measured ray data,” Laser + Photonik, (2007).

TC-2–62 2010, “Imaging-photometer-based near-field goniophotometer,” CIE Draft No. 1.

J.P. Lewis, “Fast template matching,” Vision interface, 120–123 (1995).

3M Vikuiti Brightness Enhancement Film, http://www.3m.com/ .

International Commission on Illumination (CIE), “Discomfort glare in interior lighting,” CIE Publication 117 (1995).

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Figures (9)

Fig. 1
Fig. 1

Representation of the angular binning in the XYZ coordinate system consisting of bin boundaries (black lines) and central bin directions (red lines). (a) angular binning during the first iteration for which Δθ equals 30° and Δφ equals 90°. (b) angular binning during the second iteration, after step 4.h, for which Δθ equals 18° and Δφ equals 72°.

Fig. 2
Fig. 2

Flowchart of the algorithm used to measure, process and sample a ray file of a planar light source into a set of surface sources.

Fig. 3
Fig. 3

Comparison between the measured (left column) and simulated (middle column) luminance maps for the observer positions: (θo,φo) = (0°,0°), (θo,φo) = (30°,0°), (θo,φo) = (60°,0°) and (θo,φo) = (80°,0°) of an RPLED module. Right column: percentage difference images between the measured and simulated luminance maps.

Fig. 4
Fig. 4

Horizontal cross section for (θo,φo) = (0°,0°) at Y = 11 mm for the measured (star) and simulated (circle) luminance map of the RPLED.

Fig. 5
Fig. 5

Comparison between the measured (left column) and simulated (middle column) luminance maps for the observer positions: (θo,φo) = (0°,0°), (θo,φo) = (30°,0°), (θo,φo) = (60°,0°) and (θo,φo) = (80°,0°) of an RPLED module in combination with a BEF. Right column: percentage difference images between the measured and simulated luminance maps.

Fig. 6
Fig. 6

Comparison between the measured (left column) and simulated (middle column) luminance maps for the observer positions: (θo,φo) = (0°,90°), (θo,φo) = (30°,90°), (θo,φo) = (60°,90°) and (θo,φo) = (80°,90°) of an RPLED module in combination with a BEF. Right column: percentage difference images between the measured and simulated luminance maps.

Fig. 7
Fig. 7

Comparison of a horizontal cross-section of the simulated luminance map for the observer positions (θo,φo) = (60°,0°) and (θo,φo) = (60°,90°) of an RPLED module in combination with a BEF.

Fig. 8
Fig. 8

NCC and NRMSE evaluation of the generated LIDs of the RPLED for various predefined thresholds E. The optimal point, i.e. the maximum and minimum for NCC and NRMSE, respectively, is located at a 2.1% setting for the predefined threshold.

Fig. 9
Fig. 9

NCC and NRMSE evaluation of the generated LIDs of the RPLED with a BEF for various predefined thresholds E. The optimal point, i.e. the maximum and minimum for NCC and NRMSE, respectively, is located at a 0.021% setting for the predefined threshold.

Tables (2)

Tables Icon

Table 1 Comparison between the simulated and measured luminance maps of the RPLED

Tables Icon

Table 2 Comparison between the simulated and measured luminance maps of the RPLED with BEF

Equations (6)

Equations on this page are rendered with MathJax. Learn more.

Ω B θ,φ =Δφ[ cos(min[ R θ ])cos(max[ R θ ]) ]
Φ Int,P(i,j) = θ(k) φ(l) I θ(k),φ(l) + I θ(k+1),φ(l) 2 [ cos(θ(k))cos(θ(k+1)) ]Δφ.
E= | Φ Int,P(i,j) Φ P(i,j) | Φ P(i,j) .
Diff=| L s L m |( 2 L s + L m )100.
NCC= X,Y [ ( L m ( X,Y ) L ¯ m )( L s ( X,Y ) L ¯ s ) ] [ X,Y ( L m ( X,Y ) L ¯ m ) 2 X,Y ( L s ( X,Y ) L ¯ s ) 2 ] 1/2 .
NRMSE= X,Y [ L s ( X,Y ) L m ( X,Y ) ] 2 max( L s , L m ) .

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