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Image Processing - Color Science.pptx
- 1. The Science of Color The Howand Why of Color
- 2. Color Attributes • Thereare literally millions of colors, but they can be divided into just a few color families. • And every color can be described in terms of having three main attributes: hue, saturation and brightness.
- 3. Hue • Any purecolor is referred to as a hue. • Hue is identified as the color family or color name (such as red, green, purple). • Hue is directly linked to the color's wavelength.
- 4. Saturation • Saturation, alsocalled “chroma,” is a measure of the purity of a color or how sharp or dull the color appears. • Saturation is the relative brilliance or vibrancy of a color. The more saturated a color, the less black it contains.
- 5. Brightness • Brightness, alsocalled “luminance” or “value,” is the shade (darkness) or tint (lightness) of a color. • Areas of an evenly colored object in direct light have higher brightness than areas in shadow.
- 6. Tint vs. Shade •Ahue is a specific color; red, green, blue. •A tint of a color is made by adding white. •A shade is made by adding black.
- 7. Color Wheel •Invented bySir Isaac Newton. •A tool for understanding color relationships and creating harmonious color schemes. •The color wheel is divided into three categories: primary, secondary, and tertiary.
- 8. Color Wheel • Primarycolors are those that cannot be created by mixing other colors together. • Secondary colors are those that are created by mixing two primary colors. • Tertiary colors are those that are created by mixing a primary and secondary color together. For this reason they have two- word names. Example: blue-green, yellow-orange, etc.
- 9. Warm vs. CoolColors Warm colors appear larger than cool colors.
- 10. Cool colors • Coolcolors range from blue to violet, the half of the color wheel with shorter wavelengths. • Have a calming effect. • Frequently used for backgrounds to set off smaller areas of warm colors. • Used together, cool colors can look clean and crisp, implying status and calm. • Bright cool colors generates more excitement than light, medium or dark cool colors.
- 11. Warm Colors • Warmcolors range from red to yellow. • On the half of the color wheel corresponding to the longer wavelengths. • Warm colors are active, attention-grabbing and aggressive. • They stimulate emotions, motivate and seem to come forward off the screen or page.
- 12. Color Schemes • Selectingcolor combinations may be based on several traditional color schemes. These are: – Compliments – Monochromatic – Neutral – Analogous – Low Intensity – Split Compliments – Double Compliments
- 13. Complementary Colors • Anytwo colors whose light together produces white are called complementary colors. • Complementary colors in an image are pleasing to the eye. The colors seem to belong together. • The most effective use of complements is to let one of them dominate by giving it a bigger area or a fuller saturation, while using the other as an accent.
- 14. Complementary Colors • Complementarycolors lie opposite each other on the color wheel. They complete or enhance each other. • When a pair of high intensity complements are placed side by side, they seem to vibrate and draw attention to the element. • If the hues are of low-intensity, the contrast is not too harsh.
- 15. Complementary Colors • Intensitycan only be altered by mixing a color with its complement, which has the effect of visually neutralizing the color. • Changing the values of the hues, adding black or white, will soften the effect.
- 16. Monochromatic Schemes • Amonochromatic color scheme uses only one hue (color) and all values (shades or tints) of it for a unifying and harmonious effect. • You can change the value of a color by adding black (shade), or white (tint), or gray (tone). • As white is added to a color it becomes “higher” in value (lighter). • As black is added it becomes “lower” in value (darker).
- 17. Monochromatic Colors • Valueis the relationship of light to dark. • Values that are close together give the design a calm appearance. • Values of pure hues as well as those of tints and shades create movement. • Value contrasts show texture and provide an effective means of directing viewer attention in a composition.
- 18. Neutral colors • Containsequal parts of three primary colors - black, white, gray, and sometimes brown. • When neutrals are added to a color, only the value changes. • If you try to make a color darker by adding a darker color to it, the color (hue) changes. • Black and white are thought of as neutrals because they do not change color.
- 19. Analogous Colors • Colorsthat contain a common hue and are found next to each other on the color wheel. • Adjoining colors on the wheel are similar and tend to blend together. • They are effective at showing depth.
- 20. Analogous Colors • Analogouscolor can be used to create subtle differences in an image or design by creating a peaceful and more harmonious feeling.
- 21. Intensity • Intensity isthe Brightness or dullness of a color. • A pure hue is a high- intensity color. • A dulled hue, a color mixed with its complement, is called a low-intensity color.
- 22. Triads •A color triadis composed of three colors spaced an equal distance apart on the color wheel. •The contrast between triad colors is not as strong as that between complements.
- 23. Triad - PrimaryColors • Primary Color are rarely seen as a trio except in children’s products. • Red and yellow, are popular in the USA for everything from fast food to gas stations. • Blue and red are also common, but are attractive only when separated by space.
- 24. Triad - Secondary •Colors created by mixing two primary colors to create a secondary color. • Red + yellow =orange • Yellow + blue = green • Blue + red = purple (violet)
- 25. Intermediate Triads • Colorsare created by mixing a primary and a secondary • Examples: red-orange yellow-orange yellow-green blue-green blue-purple red-purple
- 26. Split Complements • Thecombination of one hue, plus the hues on each side of its complement. • Easier to work with than a straight complementary scheme because it offers more variety. Example: red-orange, blue, and green.
- 27. Double Complements •Two hues andtheir opposites. •Four colors arranged into two complementary color pairs. •Scheme is hard to harmonize. •If all four colors are used in equal amounts, the scheme may look unbalanced. •Choose a color to be dominant or subdue the colors.
- 28. Compositional Effects ofColor: Spatial effects • Hues that are lighter at maximum saturation (yellows, oranges) appear larger than those that are darker at maximum saturation (e.g., blues and purples). • Warm colors appear closer and cool colors fall back.
- 29. Compositional Effects ofColor • A large shape or form appears to be heavier than a small shape. Several small shapes or forms can balance one large one. • An object with a complicated contour is more interesting and appears to be heavier, than one with a simple contour. A small complex object can balance a large, simple object.
- 30. Compositional Effects ofColor •Use highly saturated or high- intensity colors (a pure hue with no other colors mixed in) or busily detailed areas to draw attention. •Highly saturated colors give the appearance of carrying more weight than less saturated, low-intensity or visually simpler areas.
- 31. How Colors EffectEach Other • Placing colors next to each other effect how we see colors and is a complex part of color theory. • Red appears more brilliant against black. • Red is somewhat duller against the white. • Next orange, red appears lifeless. • In contrast with blue-green, red exhibits brilliance. • The red square appears larger on black than on other background colors.
- 32. How Colors EffectEach Other • The color of the surrounding color can affect how the color looks. • The block in the center of the examples below are the same, only the background color has changed. • Color is partially defined in our brain by the colors surrounding it.