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Lightness and Retinex Theory Journal of the Optical Society of America Vol. 61, No. 1 Jan. 1971 Edwin H. Land & John J. McCann
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Outline Introduction Independence of Color Edges Entire Field of View Physical Model The Colored Mondrian Conclusion
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Outline Introduction Independence of Color Edges Entire Field of View Physical Model The Colored Mondrian Conclusion
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Introduction Reflectance ( light or dark ) Color ( long-wave, middle-wave, and short-wave ) Color sensation ( the world & the field of view ) Departure ( for example : insert a comparison standard ) The light ( the reflectance and illuminance )
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Outline Introduction Independence of Color Edges Entire Field of View Physical Model The Colored Mondrian Conclusion
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Independence of Color The Mondrian ( avoid superposion ) Refelctance : minimum = 10% Illuminated by three projectors 1. minimize the diversity when only projector turns on 2. a wider band & more light
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Independence of Color Sharp-cut bandpass filter White rectangle ( L, M, S = 6, 35, 60 )
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Independence of Color The dark brown area The areas : bright yellow, blue, gray, lime green, and red The areas after readjusted illumination : yellow, blue, gray, green, and red Color sensation related the light ( wavelength and luminance of any point )
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Independence of Color Wearing the goggles : deep-red, dark- adaptation filter two eyes and only one eye The reports were almost the same as the previous results. Few changed the color name. Retinex = retina + cortex 3 lightness vs. 3 retinexs ( L, M, S )
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Outline Introduction Independence of Color Edges Entire Field of View Physical Model The Colored Mondrian Conclusion
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Edges Reflected luminance 40% 80%
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Edges Place a pencil over the boundary between the two gray areas.
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Outline Introduction Independence of Color Edges Entire Field of View Physical Model The Colored Mondrian Conclusion
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Entire Field of View The ratio of reflectances
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Entire Field of View Luminance
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Outline Introduction Independence of Color Edges Entire Field of View Physical Model The Colored Mondrian Conclusion
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Physical Model Luminance
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Outline Introduction Independence of Color Edges Entire Field of View Physical Model The Colored Mondrian Conclusion
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The Colored Mondrian Retinex theory : 3 retinexs Each retinex served by one set of cones
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The Colored Mondrian The black, white, and gray Mondrian the ratio of sequential products The colored Mondrian the ratio of the integrals the weighting factor of the wavelength
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Outline Introduction Independence of Color Edges Entire Field of View Physical Model The Colored Mondrian Conclusion
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The difference The function of retinex theory is to tell how the eye can ascertain reflectance in a field in which the illumination is unknowable and the reflectance is unknown.
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