BASIC COLOUR COURSE Algemeen Dit is de basisopmaak voor beeldscherm- of beamer-presentaties. Kies voor de aanmaak van nieuwe dia’s uit de opties binnen het New Slide menu. De titels en alle overige teksten worden gezet in het lettertype Denda Sans SemiBold. Het Canon logo, de rode curve en de curve aan de onderkant van de pagina staan op een vaste plaats in een vaste grootte. Breng nooit wijzigingen aan in het kleurenpallet of de achtergrondkleur. De paginanummering staat op een vaste plaats in de Denda Sans SemiBold bold 12 pt. en loopt automatisch per pagina mee. Houd alle teksten en titels zo beknopt mogelijk. Houd schema’s, tabellen en tekeningen zo eenvoudig mogelijk. Gebruik hiervoor de preset kleuren. Gebruik arceringen (patterns) van deze kleuren indien er meer varianten nodig zijn. Vermijd het gebruik van clip-art. Houd te allen tijde de leesbaarheid in de gaten. Houd daarbij rekening met het uiteindelijke formaat van de presentatie; projectie, hand-out, beeldscherm etcetera. Titelpagina De eerste optie uit het New Slide menu. Titelregel in Denda Sans SemiBold 30 pt. De subtitel, de naam en datum worden gezet in het lettertype Denda Sans SemiBold 24 pt. Tussen de subtitel en de naam een return. Klik de bulletpoint-optie uit.

Perception

Perception

Perception

Perception Colors that appear different under one illuminant but similare under another are called a metameric match. The color temperature of light is very important to the perception of color for color uniformity the ANSI (American National Standards Institute) color temp of light for uniform viewing is 5,000K to 7,500 K \ Sunlight is 4,300 to 6,500K generally 5,000K Fluorescent lamp 6,500

Light & Wavelength Light is the visible part of the electromagnetic spectrum. It behaves very similar to the waves that appear in still water Light waves however are extremely small.

Seeing Colours

The eye Retina Optical nerve Lens Rods & Cones Iris The rods are only sensitive for the intensity of light not for colour. The cones are sensitive for colour. Retina Optical nerve Lens Rods & Cones Iris

Colour Blind

Additive Colours The colour filter is transparent for the same colour, but blocks all other colours Filters R G B

Additive Primary Colours Yellow Cyan Magenta Blue White Red Green B + G R = W

Additive Primary Colours Red Blue en Green light together form White light Schematic light source

Where do we use additive colours The additive colour system - RBG Uses coloured light, Mixes different quantities of red blue and green light to produce light of different colours.

Subtractive Primary Colours Substrate is reflecting the light Groen Blauw Zwart Red Cyaan Magenta Geel + Y C = M Bk

The Subtractive Colour proces Toner colour Absorbs Reflects Shows Image C M Y M+Y C+Y C+M C+M+Y Red light Green light Blue light Green & Blue light Red & Blue light Red & Green light Red, Green & Blue light Green & Blue light Red & Blue light Red & Green light Red light Green light Blue light No light Cyan Magenta Yellow Red Green Blauw Zwart

Gamma The total colour spectre Visible Light Colour film Laser printer Bubble Jet Colour monitor

The number of Colours One bit Black or White per pixel 8 bits 16.7 million Colours

Colour Measuring Hue Brightness Saturation

The three dimensional Colour Space The Colour address

The three dimensional Colour Space

CIE models Physical CIE model Cie Lab model Grafical

Difference in Colour Space CLC9/950 CP4/660

Green Red Blue CP4/660 CLC9/950 Yellow Cyan Magenta

Color is Radiant Energy Light radiates waves similar to water The range of light waves is called the Electromagnetic spectrum Light is a form of energy called radiant energy. Radiant energy sends out waves in the same way that a rock makes circular waves when thrown into a pond. Some energy has waveslengths that are very long some have waves that are very short. Small waves can be shorter than a billionth of a meter (nm). Some waves like radio waves are very long as long as a Kilometer. The range of these waves is called the Electromagnetic spectrum. The human eye cannot see all radiant energy waves. It cannot see radio waves. There is a range that it can see and this range is called the visible spectrum

Visible Light Human color perception range Ultraviolet (UV) 400 nm waves Infrared (IR) 700 nm waves

3 elements of the sensation of color light source colored object light sensor

Human eye and color The human eye can see almost 10 million different colors 1.) Object being observed 2.) Light refracting from object 3.) Lens 4.) Pupil (aperature) 5.)iris 6.) retina 7.) rods & cones 8.) optic nerve Light passes into the eye, the iris rugulates the amount of light that flows through lens to the retina. The pupil is the aperature. The lens focuses the light on the retina based on its wavelength. The retina, which is considered to be part of the brain, is a complex nerve structure containing light-sensitive receptors that are responsible for translating incoming light into nerve impulses. Because of their physical appearence, these receptors are known as rods and cones. Rods function in low or dim light and are responsible for night or low light vision. The rods in the retina are receptive to a broad range of light intensities but do not destinguish color. Cones function in daylight and contain light sensitive chemicals called phtotpigments. these photopigments contribute to color sensation. The cones are sensitive to different wavelengths, which the brain interprets as color. The cones are particularly sensetive to lower (Violet/blue), middle (green), and high(reds) wavelengths of the spectrum. Optic Nerve From the retina, the information from the rods and cones travels along the optic nerve t5o the brain. What the brain sees is the experience or the viewer and the condition the rods and cones on his or her retina

Primary colors of light Red, Green, and Blue are the primary colors of light The reason they are called primary is that by combining them, all lthe colors in the rainbow can be created. Light waves are measured in wavelengths. The lengthof a light wave determines its color. The spectrum is measured in nanometers (1 billionth of a meter). A wave is measured from 1 trough to the next trough that distance determines the length of the wave and in turn what color it represents. By combining Red, Green, and Blue we can create all the colors in the rainbow or the entire spectrum of visable light

How we perceive colour RGB light is combined to produce white light when the light is projected at the red sphere it absorbs blue and green light and reflects the red light The human eye perceives color based upon the objects that light is reflected from, absorbed by and transmitted through.

Color models Methods of ordering color 1. physical (device dependent) RGB CMYK Pantone trumatch 2. mathematical (device independent) HSL CIE Lab

HSL/HSV Color model Device independent color (mathematical model) Color based upon HUE Saturation Lightness or Value Developed in the 1930’s in Europe by the “International commision on color” CIE The closer you get to the top of the vertical (value, Lightness) scale the whiter the colors become The closer you get to the bottom the darker they become

CIE Color model Device independent color (mathematical model) Utilizes a mathematical model of human vision Tristimulous method of measuring color Developed in the 1930’s in Europe by the “International commision on color” The Z is running perpendicular to the x and y plane. Z is equivalent to lightness and x and y are used to specify the chromaticity of a color. The spectrum of colors lie on the perimiter of the chromaticity diagram, while the color temperatures of a series of white points are towards the center. From the outside is a gradation of colors decreasing in saturation as they come towards the center. The model was created in the 1931 to define and measure color based on the human visual response. The perceived color of an object is dependent not only on the object’s characteristics but also the characteristics of the viewing illuminant and the observer. The CIE system has defined a set of standard viewing illuminants and a standard observer. The CIE system has a number of standard viewing illuminants (defined by there spectral power i.e. radiation distribution) the most important is D65, which is similar to daylight and has a K of 6,500° The CIE system has standard observer view the colors at 2° and 10° these angles are known as the 2° and 10° observer EFICOLOR uses a variation of CIE XYZ D50

CIE LAB Color model Device independent color (mathematical model) Color model based upon human vision A non-linear transform of the CIE XYZ color space designed to improve its perceptual uniformity. It was designed to appear less distorted to the human eye A linear transform is an equation relating some quantity to lthe weighted sum, or difference, of otlher quantities. A nonlinear transform is an equation relating some quantitiy to some higher order mathematical function (eg square or cube root) of other quantities Burger page A-9 CIE LAB was designed for the graphics industry

RGB Color model Physical model•Device dependent Additive color Red Green and Blue are combined to produce white Device dependent color space; We call them device dependent because, for example, the color produced on a monitor in response to a particular RGB signal value depends not only on the RGB value itself, but also on the type of phosphor used in the CRT. Likewise the RGB signal produced by a scanner depends not only on the spectral reflectance of the scanned ofbject obut also on the scanners light source and color separation filters. Finally, the colorproduced on a printer depends on the formulation of the inks and the type of paper used in the printing process. The same CMY pixel value may produce very different colfors when imaged on two different printers. Device color values map directly to the amounts of device colorant. Simply knowing the RGB or CMY value of a poxel does not tell us what the color will be once the pixel has been reporduced on a randomly selected output device.

CMYK Color model (physical model •Device dependent) Subtractive color Cyan, Magenta, and Yellow are combined to produce black

Pantone Color model (physical model •Device dependent) A colorstandard for the graphic arts industry The system is based upon (mixing) 13 basic Pantone primaries color in addition to Pantone black and a opaque Pantone white. This system is not based upon process colors therefore CMYK inks, pigments, or toners cannot properly emulate pantones. Process pantones are Pantones own process color “emulations” of Pantone colors. Color copiers do not have white toner therefore they are unable to change the % of saturation of the Hue. They are also unable to produce metallic or florescent colors.

Color Gamut The range of colors that can be produced by a color device Gamut is defined as the range of colors that can be rendered on a specific output device Gamut mapping is the process of transforming colors values that out-of-Gamut for a specific sevice into printable colors

Color Space Conversions Color separation RGB to CMYK Separation Theory Gamut Mapping PostScript Level 2 CRD’s GCR/UCR/BG

Color Separation RGB to CMYK Transformation of RGB image into CMYK colors for printing A black component is added Since the Red filter is composed of Magenta and Yellow pigments it will reflect those colors and only allow the Cyan portion of the image to show through White light + Red filter = Cyan seperation Since the Green filter is composed of Yellow and Cyan pigments it will reflect those colors and only allow the Magenta portion of the image to show through White light + Green filter = Magenta seperation Since the Blue filter is composed of Magenta and Cyan pigments it will reflect those colors and only allow the Yellow portion of the image to show through White light + Blue filter = Yellow seperation

RGB to CMYK: Gamut mapping Transforming out-of-range colors into printable colors Color Rendering Dictionaries EFIColor Management system Gamut is defined as the range of colors that can be rendered on a specific output device Gamut mapping is the process of transforming colors values that are out-of-Gamut for a specific sevice into printable colors It is impossible to make this transition without the loss of some color information

Color Separation What is a Color Rendering Dictionary A style of gamut mapping Intelligent conversion from the RGB to the CMYK based on the origin and destination Only on PostScript level 2 devices such as Fiery color servers Photographic Solid Presentation A CRD is a three dimensional lookup table specifying the transform from an input (source) color space to the color space of a target (destination) output device

CRD: Solid when colour accuracy is crucial does the best job of preserving the saturation of colours The white circles in the CMYK Gamut represent colors that are out of the printers gamut, the red circles represent colors that are in the printers gamut. With Solid Color redering only the colors that fall outside the printers gamut are remapped (they are mapped to their closest corosponding color) the colors that fall inside the printers gamut are left untouched. In color theory this is called Colorimetric rendering and is optimal for producing solid color. The disivantage of this rendering style is that many colors outside the printable gamut will get mapped to the same place. That is why this style is unacceptable for continuous tone images.

CRD: Presentation Bright saturated colour used in illustration and graphs for business presentations

The electromagnetic Spectre

White light and the Colour spectre

Light Sources & Colour Spectra

Sources of Colour

HSL Concepts