Presentation is loading. Please wait.

Presentation is loading. Please wait.

Cônes et bâtonnets.

Similar presentations


Presentation on theme: "Cônes et bâtonnets."— Presentation transcript:

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% 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

14

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

16 Codage des couleurs

17 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)

18 Décorrelation

19

20

21

22

23

24

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

26 Approximation de 6 réflectivités
3 fonctions de base 2 fonctions de base 1 fonction de base

27 Fonctions de base de réflectivité

28

29

30 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.


Download ppt "Cônes et bâtonnets."

Similar presentations


Ads by Google