Recent Papers Colors in Dim Illumination and Candlelight A variety of papers have studied color at low-light levels in different illuminants. This paper reviews these results and adds new experiments using long-wave-rich illumination, appropriate for rod and long-wave cone interactions. The experimental results agree with and extend previous results. Since these experiments use illuminates more appropriate for rod-cone interactions they measure a much greater range of colors. They also provide new data that clarifies how the rod information interacts with the cone-cone color channels. Color appearances indicate rods share M- and S-color channels. J. McCann, “Colors in Dim Illumination and Candlelight”, in Proc. IS&T/SID Color Imaging Conference, Albuquerque, vol. 15, 2007. 07rodMatch.pdf Rod – Lcone color matching in complex images Rod and L-cone interactions generate color appearances. This paper measure these appearances in complex scenes above and below-M and S-cone thresholds. The test target was a ColorChecker viewed in tungsten light and 1 wax candle. Firelight is an ideal illuminant for Rod-Lcone color. The observers’ task was to adjust RGB digits in LCD computer display to match the appearance of the ColorChecker. With the tungsten illumination, above L-,M-,& S-cone thresholds, the L*a*b* values for the reflective ColorChecker and the emissive LCD were reasonably close. With 1 candle illumination, the below M- and S-cone threshold ColorChecker showed matches marked different in L*a*b* values. A 4-D color space is not required because all colors were matched to above cone threshold colors, sharing information with other color channels. The color appearances are not consistent with rods sharing S-channel alone, or M-channel alone. The colors are not consistent with the rods desaturating all three channels. Under these conditions, the colors are consistent with the rod spatial comparisons sharing both the M- and the S-cone channels. J. J. McCann, “Rod – Lcone color matching in complex images”, in Perception ECVP Abstract Supplement, 2007. 07ECVP.pdf Ideal Illuminants for Rod /L-Cone Color Humans see multicolor complex images with illuminants that have very low amounts of 400 to 580 nm light when there is enough long-wave light greater than 590 nm. Interactions between rods and long-wave (L) cones generate these colors. They are observed when there is insufficient light for a threshold response from M- and S-cones. This paper measures the spectral emission of a wood fire and a wax candle and it compares these low-color temperature spectral radiant exitances with the sensitivities of rods and long-wave cones. The paper reviews some of the literature on the evolution of human cone pigments and the early use of fire by hominids. J. J. McCann, “Ideal Illuminants for Rod /L-Cone Color”, in Electronic Imaging XI: Processing, Hardcopy, and Applications; R. Eschbach, G. Marcu; Eds., Proc. SPIE, 6058, 1-8, 2006. Rod Lcone Fire.pdf Chronology of Papers (1969-2007) J.J. McCann, and J. L. Benton, " Interactions of the Long-Wave Cones and the Rods to Produce Color Sensations ", J. opt. Soc. Am., 59, 103-107, 1969. 69JOSA McCann&Benton.pdf J.J. McCann, " Rod-Cone Interactions: Different Color Sensations from Identical Stimuli ", Science, 176, 1255-1257, 1972. 72_Science J.J. McCann, " Human Color Perception ", in Color Theory and Imaging Systems , 1-23, Soc. Phot. Sci. & Eng., R. Eynard, ed. Washington, DC, 1973. 1973SPSE.pdf S. P. McKee , J. J. McCann, and J.L Benton , " Color Vision from Rod and Long-Wave Cone Interactions: Conditions in which Rods contribute to Multicolored Images ", Vis. Research 17, 175-185, 1977. 77_VisRes J. L. Benton , and J. J. McCann, " Variegated color sensations from rod-cone interactions: Flicker-fusion experiments ", J. opt. Soc. Am. 67, 119-121, 1977. 77 JOSA J. J. McCann, J. L. Benton, S. P. McKee, Red/White Projections and Rod-Lcone Color: An Annotated Bibliography, J. Electron. Imaging 13, 8-14, 2004. 04_JEI J. J. McCann, “Rod – Lcone color matching in complex images”, in Perception ECVP Abstract Supplement, 2007. 07ECVP.pdf J. J. McCann, “Ideal Illuminants for Rod /L-Cone Color”, in Electronic Imaging XI: Processing, Hardcopy, and Applications; R. Eschbach, G. Marcu; Eds., Proc. SPIE, 6058, 1-8, 2006. Rod Lcone Fire.pdf J. McCann, “Colors in Dim Illumination and Candlelight”, in Proc. IS&T/SID Color Imaging Conference, Albuquerque, vol. 15, 2007. 07rodMatch.pdf

Recent Papers

Colors in Dim Illumination and Candlelight

A variety of papers have studied color at low-light levels in different illuminants. This paper reviews these results and adds new experiments using long-wave-rich illumination, appropriate for rod and long-wave cone interactions. The experimental results agree with and extend previous results. Since these experiments use illuminates more appropriate for rod-cone interactions they measure a much greater range of colors. They also provide new data that clarifies how the rod information interacts with the cone-cone color channels. Color appearances indicate rods share M- and S-color channels.

J.J. McCann, “Colors in Dim Illumination and Candlelight”,

in Proc. IS&T/SID Color Imaging Conference, Albuquerque,

vol. 15, 2007.

07rodMatch.pdf

Rod – Lcone color matching in complex images

Rod and L-cone interactions generate color appearances. This paper measure these appearances in complex scenes above and below-M and S-cone thresholds. The test target was a ColorChecker viewed in tungsten light and 1 wax candle. Firelight is an ideal illuminant for Rod-Lcone color. The observers’ task was to adjust RGB digits in LCD computer display to match the appearance of the ColorChecker. With the tungsten illumination, above L-,M-,& S-cone thresholds, the L*a*b* values for the reflective ColorChecker and the emissive LCD were reasonably close. With 1 candle illumination, the below M- and S-cone threshold ColorChecker showed matches marked different in L*a*b* values. A 4-D color space is not required because all colors were matched to above cone threshold colors, sharing information with other color channels. The color appearances are not consistent with rods sharing S-channel alone, or M-channel alone. The colors are not consistent with the rods desaturating all three channels. Under these conditions, the colors are consistent with the rod spatial comparisons sharing both the M- and the S-cone channels.

J. J. McCann, “Rod – Lcone color matching in complex images”, in Perception ECVP Abstract Supplement, 2007.

07ECVP.pdf

Ideal Illuminants for Rod /L-Cone Color

Humans see multicolor complex images with illuminants that have very low amounts of 400 to 580 nm light when there is enough long-wave light greater than 590 nm. Interactions between rods and long-wave (L) cones generate these colors. They are observed when there is insufficient light for a threshold response from M- and S-cones. This paper measures the spectral emission of a wood fire and a wax candle and it compares these low-color temperature spectral radiant exitances with the sensitivities of rods and long-wave cones. The paper reviews some of the literature on the evolution of human cone pigments and the early use of fire by hominids.

J. J. McCann, “Ideal Illuminants for Rod /L-Cone Color”, in Electronic Imaging XI: Processing, Hardcopy, and Applications; R. Eschbach, G. Marcu; Eds., Proc. SPIE, 6058, 1-8, 2006.

Rod Lcone Fire.pdf

Chronology of Papers (1969-2007)

J.J. McCann, and J. L. Benton,

" Interactions of the Long-Wave Cones and the Rods to Produce Color Sensations ",

J. opt. Soc. Am., 59, 103-107, 1969.

69JOSA McCann&Benton.pdf

J.J. McCann,

" Rod-Cone Interactions: Different Color Sensations from Identical Stimuli ",

Science, 176, 1255-1257, 1972.

72_Science

J.J. McCann,

" Human Color Perception ",

in Color Theory and Imaging Systems , 1-23,

Soc. Phot. Sci. & Eng., R. Eynard, ed. Washington, DC, 1973.

1973SPSE.pdf

S. P. McKee , J. J. McCann, and J.L Benton ,

" Color Vision from Rod and Long-Wave Cone Interactions: Conditions in which Rods contribute to Multicolored Images ",

Vis. Research 17, 175-185, 1977.

77_VisRes

J. L. Benton , and J. J. McCann,

" Variegated color sensations from rod-cone interactions: Flicker-fusion experiments ",

J. opt. Soc. Am. 67, 119-121, 1977.

77 JOSA

J. J. McCann, J. L. Benton, S. P. McKee,

Red/White Projections and Rod-Lcone Color: An Annotated Bibliography,

J. Electron. Imaging 13, 8-14, 2004.

04_JEI

J. J. McCann, “Rod – Lcone color matching in complex images”, in Perception ECVP Abstract Supplement, 2007.

07ECVP.pdf

J. J. McCann, “Ideal Illuminants for Rod /L-Cone Color”, in Electronic Imaging XI: Processing, Hardcopy, and Applications; R. Eschbach, G. Marcu; Eds., Proc. SPIE, 6058, 1-8, 2006.

Rod Lcone Fire.pdf

J.J. McCann, “Colors in Dim Illumination and Candlelight”, in Proc. IS&T/SID Color Imaging Conference, Albuquerque, vol. 15, 2007.

links:

paper list

The range of rod/Lcone colors fall in a two-dimension plane in 3-D color space. The colors show that the rod lightnesses are sent to both the M and Scone channels.

An ideal illuminant for

rod /Lcone interactions is firelight.

Firelight has about 100 times more long-wave light than short-wave light. There is enough stimulus for long-wave cones, while too little for middle- and short-wave light. Rods responds to the dim short-wave light. The lightness information from the rods, when compared with the Lone lightness, generate rod/Lcone colors.

The rods are a perfectly good color receptor.

The rods interact with the long-wave cones (Lcones) to generate color sensations, as demonstrated in the following experiments.