GC 3460 EXAM 2 QUESTIONS AND
ANSWERS
color perception issues - ANSWER-chromatic adaptation, retinal fatigue, simultaneous contrast
chromatic adaptation - ANSWER-fools someone into observing a color basis optical illusion
retinal fatigue - ANSWER-stare at an object and then look at something blank and see the inverse object.
caused by fatiguing color receptors in the eye. when you look away the fatigued colors are gone and you
will see the complementary colors.
ex: yellow and cyan american flag will burn image of blue and red flag
simultaneous contrast - ANSWER-when the brain interprets colors differently based on their
surroundings.
ex: two gray squares surrounded by different colors appear to not be the same color, when in fact they
are.
3 requirements for color - ANSWER-light, observer, and object
light - ANSWER-are quantified as illuminants
observer - ANSWER-quantified by standard observer functions
object - ANSWER-are quantified through spectral data
young-hemholtz theory trichromatic color theory - ANSWER-cones are red, green, blue, receptors
hering opponent theory - ANSWER-rods are light/dark, some cones are red/green some cones are
yellow/blue (think L*A*B)
opponent process model - ANSWER-nerve cells act as intermediary and send light/dark, red/green,
yellow/blue signals.
3 kinds of cones - ANSWER-small wave blue, medium wave green, long wave red.
tests for color deficiencies - ANSWER-munsell-farnsworth 100-hue test, ishihara test
munsell-farnsworth 100-hue test - ANSWER--put the shades of color in order
-tests ability to differentiate between changes in hue
-1905- develops color order system built on hue, value (lightness), and chroma.
ishihara test - ANSWER--a number will appear in different colors in the center or other colors
-tests for color blindness
physiology of perception - ANSWER--environment
-fatigue
-heredity
-age
psychology of perception - ANSWER--these affect us because we are so used to seeing this color, it is
easy to tell when something in an image is not right
ex: grass that is too green
-culture
-memory colors (grass, sky etc., neutrals, fleshtones)
ordered color system - ANSWER-LAB, LCH, XYZ
-provides logical progression
-values can be understood without a physical sample
-describes color by hue, chroma and value
hue - ANSWER-attribute of a color by which we distinguish red from green, blue from yellow, etc.
, chroma - ANSWER-the degree of departure of color from the neutral color of the same value (weak to
strong).
value - ANSWER-the lightness of a color 0 (pure black) 10 (pure white)
non-ordered color system - ANSWER-pantone, focoltone, toyo colors
-does not provide consistence
-can provide means of color specification, but not means to explain the difference
-creates system of recreating consistent colors however, standards change overtime
color standards - ANSWER-spectral data quantifies objects
illuminates - ANSWER-quantifies the light source
observer functions - ANSWER-determines what an average observer is by looking at data form peoples
sensitivities at various temperatures of light
color specification - ANSWER-an ordered, logical, and incremental system
-independent color space
-accurate, quantified color description
-means of defining color difference
-number enhance communication
munsell - ANSWER-developed color system built on hue, value and chroma
-notation= H V/C, where h=hue v=value c=chroma
CIELAB - ANSWER--l=lightness 0=black 100=white
-+A=redness -A=greeness
--B=blueness +B=yellowness
explain and calculate color difference, delta e - ANSWER-you must have a sample and a reference to
calculate delta e of any color. the delta e calculates the difference of the LAB numbers between a
reference, what color something should be, and a sample, the actual color that was printed. (L1-L2)^2 +
(a1-a2)^2 + (b1-b2)^2
metamerism - ANSWER-when two objects with different spectral reflectance curves appear the same
under one light source, yet different under another.
fundamentals of color theory - ANSWER-color wheel, color harmony
color wheel - ANSWER-based on red, blue, and yellow (primary colors) to get secondary colors like
orange, green and purple.
color harmony - ANSWER-a. analogous colors: 3 colors side by side on 12 part color wheel ex: yellow-
green, yellow, yellow-orange
b. complementary colors: directly opposite each other on color wheel ex: orange and blue
c. warm vs. cool colors
densitometer - ANSWER--measures the amount of light present and report the light absorbed
-doesnt measure color
-transmissive
-measure the amount of light that is transmitted through a transparent medium such as photographic
film (how much light is being absorbed).
reflective - ANSWER--measure the amount of light reflected back from a surface
-black and white or opaque and clear
colorimeter - ANSWER--measures color by incorporating all 3 colors (RGB) to give one response taking
into account the 2 degrees observer
-can measure EXY tristimulus values and calculate CIELAB
-but its dependent on light course and observer function; cannot detect metamers
ANSWERS
color perception issues - ANSWER-chromatic adaptation, retinal fatigue, simultaneous contrast
chromatic adaptation - ANSWER-fools someone into observing a color basis optical illusion
retinal fatigue - ANSWER-stare at an object and then look at something blank and see the inverse object.
caused by fatiguing color receptors in the eye. when you look away the fatigued colors are gone and you
will see the complementary colors.
ex: yellow and cyan american flag will burn image of blue and red flag
simultaneous contrast - ANSWER-when the brain interprets colors differently based on their
surroundings.
ex: two gray squares surrounded by different colors appear to not be the same color, when in fact they
are.
3 requirements for color - ANSWER-light, observer, and object
light - ANSWER-are quantified as illuminants
observer - ANSWER-quantified by standard observer functions
object - ANSWER-are quantified through spectral data
young-hemholtz theory trichromatic color theory - ANSWER-cones are red, green, blue, receptors
hering opponent theory - ANSWER-rods are light/dark, some cones are red/green some cones are
yellow/blue (think L*A*B)
opponent process model - ANSWER-nerve cells act as intermediary and send light/dark, red/green,
yellow/blue signals.
3 kinds of cones - ANSWER-small wave blue, medium wave green, long wave red.
tests for color deficiencies - ANSWER-munsell-farnsworth 100-hue test, ishihara test
munsell-farnsworth 100-hue test - ANSWER--put the shades of color in order
-tests ability to differentiate between changes in hue
-1905- develops color order system built on hue, value (lightness), and chroma.
ishihara test - ANSWER--a number will appear in different colors in the center or other colors
-tests for color blindness
physiology of perception - ANSWER--environment
-fatigue
-heredity
-age
psychology of perception - ANSWER--these affect us because we are so used to seeing this color, it is
easy to tell when something in an image is not right
ex: grass that is too green
-culture
-memory colors (grass, sky etc., neutrals, fleshtones)
ordered color system - ANSWER-LAB, LCH, XYZ
-provides logical progression
-values can be understood without a physical sample
-describes color by hue, chroma and value
hue - ANSWER-attribute of a color by which we distinguish red from green, blue from yellow, etc.
, chroma - ANSWER-the degree of departure of color from the neutral color of the same value (weak to
strong).
value - ANSWER-the lightness of a color 0 (pure black) 10 (pure white)
non-ordered color system - ANSWER-pantone, focoltone, toyo colors
-does not provide consistence
-can provide means of color specification, but not means to explain the difference
-creates system of recreating consistent colors however, standards change overtime
color standards - ANSWER-spectral data quantifies objects
illuminates - ANSWER-quantifies the light source
observer functions - ANSWER-determines what an average observer is by looking at data form peoples
sensitivities at various temperatures of light
color specification - ANSWER-an ordered, logical, and incremental system
-independent color space
-accurate, quantified color description
-means of defining color difference
-number enhance communication
munsell - ANSWER-developed color system built on hue, value and chroma
-notation= H V/C, where h=hue v=value c=chroma
CIELAB - ANSWER--l=lightness 0=black 100=white
-+A=redness -A=greeness
--B=blueness +B=yellowness
explain and calculate color difference, delta e - ANSWER-you must have a sample and a reference to
calculate delta e of any color. the delta e calculates the difference of the LAB numbers between a
reference, what color something should be, and a sample, the actual color that was printed. (L1-L2)^2 +
(a1-a2)^2 + (b1-b2)^2
metamerism - ANSWER-when two objects with different spectral reflectance curves appear the same
under one light source, yet different under another.
fundamentals of color theory - ANSWER-color wheel, color harmony
color wheel - ANSWER-based on red, blue, and yellow (primary colors) to get secondary colors like
orange, green and purple.
color harmony - ANSWER-a. analogous colors: 3 colors side by side on 12 part color wheel ex: yellow-
green, yellow, yellow-orange
b. complementary colors: directly opposite each other on color wheel ex: orange and blue
c. warm vs. cool colors
densitometer - ANSWER--measures the amount of light present and report the light absorbed
-doesnt measure color
-transmissive
-measure the amount of light that is transmitted through a transparent medium such as photographic
film (how much light is being absorbed).
reflective - ANSWER--measure the amount of light reflected back from a surface
-black and white or opaque and clear
colorimeter - ANSWER--measures color by incorporating all 3 colors (RGB) to give one response taking
into account the 2 degrees observer
-can measure EXY tristimulus values and calculate CIELAB
-but its dependent on light course and observer function; cannot detect metamers
