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Cônes et bâtonnets

Cônes et bâtonnets. Sensibilité spectrale des photorécepteurs. Mélange soustractif des couleurs (pigments). Mélange additif des couleurs (lumières). Color matching. Trichromacy. Trichromacy (Young-Helmholtz). 3 primaires = blanc X = A + B+ C Télévision, imprimerie. Munsell system.

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Cônes et bâtonnets

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  1. Cônes et bâtonnets

  2. Sensibilité spectrale des photorécepteurs

  3. Mélange soustractif des couleurs (pigments)

  4. Mélange additif des couleurs (lumières)

  5. Color matching

  6. Trichromacy

  7. Trichromacy (Young-Helmholtz) • 3 primaires = blanc • X = A + B+ C • Télévision, imprimerie

  8. Munsell system

  9. Sensibilité spectrale des cônes Figure 1. Spectral sensitivity of the S-cone, M-cone and L-cone. Combined results from various authors using different methods including retinal densitometry from Rushton (t and Ñ ), microspectrometry from Brown and Wald (n and “ ) and increment threshold producing artificial monochromasy from Brinley (D and s ) and increment threshold measurements from Wald (5 ) (From Moses, R. A. and Hart, W. M. (Ed) Adler's Physiology of the Eye, Clinical Application. St. Louis: The C. V. Mosby Company, 1987.(12 K jpeg image)

  10. Champs de sensibilité aux couleurs

  11. Table 1 Prevalence of congenital colour deficiencies Types of colour vision deficiency males females Overall ~8% ~0.5% Anomalous trichromacy protanomaly 1% 0.01% Deutanomaly 5% 0.4% tritanomaly rare rare Dichromacy protanopia 1% 0.01% Deuteranopia 1.5% 0.01% tritanopia* 0.008% 0.008% Monochromacy rod monochromacy rare rare cone monochromacy rare rare atypical monochromacy v. rare v. rare Modified after Cole (1972), Pease (1998) and estimates from Wright (1952)*

  12. Opponency (Hering) • Post-images • Noms des couleurs 4: R V J B • Pas de teintes RV, JB • Lumière blanche = R + V = J + B • Jameson & Hurvich hue cancellation

  13. Hue cancellation (Jameson & Hurvich) monochromatique ajouter V ou R pour paraître ni V ni R

  14. Codage des couleurs

  15. Sensibilité spectrale des cônes Figure 1. Spectral sensitivity of the S-cone, M-cone and L-cone. Combined results from various authors using different methods including retinal densitometry from Rushton (t and Ñ ), microspectrometry from Brown and Wald (n and “ ) and increment threshold producing artificial monochromasy from Brinley (D and s ) and increment threshold measurements from Wald (5 ) (From Moses, R. A. and Hart, W. M. (Ed) Adler's Physiology of the Eye, Clinical Application. St. Louis: The C. V. Mosby Company, 1987.(12 K jpeg image)

  16. Décorrelation

  17. Modèle bilinéaire de la constance des couleurs Maloney & Wandell, 1986

  18. Approximation de 6 réflectivités 3 fonctions de base 2 fonctions de base 1 fonction de base

  19. Fonctions de base de réflectivité

  20. Sommation spatiale et temporelle THE LAWS OF SPATIAL and TEMPORAL SUMMATION Spatial Summation: RICCO'S LAW the detectability of a near-threshold flash of light depends only on the product (photons per unit area) X (flash area). Holds only for spots up to 1 degree across at most (in rod vision), and only for very very tiny spots in foveal vision. (NOTE: error in text book) Temporal Summation: BLOCH's LAW the detectability of a near-threshold flash of light depends only on the product (photons/ unit time) X (flash duration). Holds up to 0.2 sec inrod vision, but only up to around 0.05 sec in cone vision.

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