What will be on the final exam CS 178 Spring 2010 You should also review the material from the first half of the course We won t emphasize it on this exam but we might use it here and there Marc Levoy Computer Science Department Stanford University Trichromatic theory 1 of 2 interaction of light with matter understand spectral power distributions SPDs multiplying illumination reflectance wavelength by wavelength color response basis for color discrimination meaning of a metamer monochromats versus dichromats trichromats N chromats understand the tristimulus sensitivity functions and how one computes from them and a stimulus spectrum understand the linearity of light and retinal response you won t need to perform calculus derivations on the exam 3D colorspace how one plots for a spectrum or mixtures of spectra understand the spectral locus and gamut of perceivable colors 2 Marc Levoy Trichromatic theory 2 of 2 reproducing colors using primaries understand how the color matching experiment works understand trichromatic matching functions including negative values and the gamut of reproducable colors for a given set of primaries effect of pure single wavelength versus impure primaries the effect of adding extra primaries additive versus subtractive mixing when is additive mixing relevant and when is subtractive which spectra are best for additive subtractive primaries effect of moving the primaries around adding extra primaries don t worry about printing via the Neugebauer equations 3 Marc Levoy Applications of color cylindrical color systems linear versus circle versus rainbow extra spectral purples meaning of scales for hue saturation and lightness value chromaticity diagrams construction and properties of the of rg b and xy z spaces for xy z know the matching functions are all positive what is color temperature and correlated color temperature how is white balancing performed in digital photography know the gray world method for auto white balancing procedure for obtaining the xy coordinates for a real object what is a device gamut and how is gamut mapping done don t need to know the details of L a b YIQ YCbCr sRGB rendering intents but understand what they are memorize the Calvin and Hobbes cartoon on color Marc Levoy 4 Light and reflection radiometry versus photometry understand the distinction and the luminous efficiency curve the four measures of radiance know their definitions and units watts steradians m2 don t worry about photometric units nits lux etc don t memorize the examples we gave but be able to reason about new problems we may pose along these lines reflection of light meaning of the terms diffuse specular albedo microfacets be able to reason about mirror reflections perspective focus be able to interpret or sketch a goniometric diagram meaning of terms retroreflectivity anisotropic reflection BRDF BSSRDF don t worry about Fresnel equations 5 Marc Levoy Photographic lighting taxonomy of light sources studio lighting spatial versus angular extent point versus extended sources parallel versus diffusing sources umbra versus penumbra know the terms floodlight spotlight barn doors diffusers main key fill accent rim grazing brightfield darkfield don t worry about the bas relief ambiguity flash effects of flash placement fill flash flash plus ambient relationships of flash duration shutter speed aperture ISO understand guide numbers 2nd curtain sync how do digital cameras meter for flash photography understand problems with flash and flash color temperature 6 Marc Levoy In camera image processing demosaicing tone mapping be able to compare gamma transform histogram equalization don t worry about details of HDR tone mapping denoising and sharpening linear interpolation and its problems moir don t worry about median filtering of chrominance roughly understand bilateral filtering and unsharp masking compression what is JPEG EXIF and RAW what are the steps in JPEG compression don t need to know formulas or detailed algorithms 7 Marc Levoy Panoramas what assumption underlies panoramic mosaicing what are the steps required to stitch a panorama rotation around the center of perspective find correspondences compute transformation warp blend understand perspective versus cylindrical projection for perspective reprojecting to a common picture plane simulates having had a wide angle camera in the first place for cylindrical project onto a cylinder to create a panorama then reproject to a plane for display 8 Marc Levoy List of important formulas will be replicated on exam sheets 700nm 700nm 700nm Le d Le d Le d 400nm 400nm 400nm 700nm 700nm 700nm R G B Le r d Le g d Le b d 400nm 400nm 400nm R r R G B G g R G B 700nm 700nm 700nm X Y Z Le x d Le y d Le z d 400nm 400nm 400nm 9 X x X Y Z Y y X Y Z Marc Levoy List of important formulas continued 700nm L Le V d 400nm P I watts steradian P E A watts 2 m V P L A cos watts steradian m 2 BRDF fr i i r r 1 sr BSSRDF xi yi i i xr yr r r 1 sr 1 steradian of solid angle sr r2 4 r2 aperture size flash guide number distance to subject 10 luminance of a CRT voltage where 2 5 Marc Levoy