Module Code: CU0001NI

Introduction to Multimedia

Week – 3 - Extra

• Vector Drawing Programs provide a basic set of shapes that can easily be represented mathematically and manipulated using anchor points and bézier curves

Vector Graphics

Drawing Bitmaps

Antialiasing bitmap images

Understanding bitmap image file sizes

• Resoluton of scanners and printers usually described in terms of their pixel density, as dots per inch dpi; e.g. 2400 dpi

• Resoluton of a sti lls camera usually described by the total number of pixels it can capture in the largest image it can record; e.g. 24 Megapixels

Understanding bitmap image file sizes

• Image Size is determined by the number of pixels making up the image. The screen resoluti on and the image size determine how much of the screen is occupied by the image. For example, if the image size is 640 * 480 and the screen resoluti on is 640 * 480, then the image will occupy the entire screen.

File Formats:

• Graphic images can be saved in a variety of file formats. The popular formats include:

• • TIFF (Tagged Image File Format)• • BMP (Bitmap)• • PCX (Windows Paint)• • PICT (Macintosh picture format), which are the

standard file formats for multi media development;

• • JPEG (Joint Photographer Experts Group)• • GIF (Graphics Interchange File format)• • PNG (Portable Network Graphics), are the

standard file formats for the World Wide Web.

Colour Theory

Light is an electromagnetic wave.

If we can see an object, that's because it is giving off or reflecting. The sun gives off light. Humans reflect light.

When sunlight shines on us, we can reflect it, absorb it, or transmit it.

Colour Theory

You see me because some light reflects off me.

I stay warm because I absorb some sunlight.

I see the sun because of the sunlighttransmitted through my corneas to myretinas

Colour Theory

"Light" is the limited range of electromagnetic wavelengths that are visible to the human eye. (Electromagnetic waves we don't see include x- ‐ rays, infrared, ultraviolet, and radio.)

"Colour" is our ability to distinguish one wavelength of light from another, just by looking at it.

Colour Theory

Two basic colour systems

Additive; primary, direct light source

Subtractive; secondary, reflective light source

Primary System

Red Green Blue

Mixed together make white

Additive Colours

Additive Colour System

Objects have no colour themselves

Only the ability to reflect / absorb light

No reflection = no colour

Subtractive Colours

How we generally view colours (day to day)

A Secondary System (reflected)

Subtractive Colours

Cyan, Yellow, Magenta is a secondary system used in print, (blue red and yellow in painting)

An absence of ink (assuming white paper) gives white, colour is subtracted out hence subtractive system

Mixed together make BlackIn printing Black is an additional Colour

Subtractive Colours

The colour wheel can be used as a valuable tool for determining harmonious colours etc.

Primary Secondary Tertiary

Vector Graphics

Source Wikipedia

Harmonious and Complementary Colours

• Harmonious colours are colours that work well together, that produce a colour scheme that looks attractive.

• The colour wheel can be used as a valuable tool for determining harmonious colours

Harmonious and Complementary Colours

• Complementary colours are colours directly across from each other on the wheel. These are typically colours that will produce a strong contrast.

• Triad colours represent three colours equidistant on the colour wheel; this typically provides a balanced colour scheme with reasonable contrast

Harmonious and Complementary Colours

• Analogous colours are colours next to each other on the colour wheel. They typically harmonize well but may not provide enough contrast.

• Monochromatic colours are all shades and tints of the same colour

• Cool colours have a blue undertone, and include violets, blues, aquas, and greens.

• When they are used together, cool colours seem to move away from the viewer, and express coolness, detachment, stability, and calmness.

Cool Colours

Warm colours are all those that have a yellow undertone, such as bright red, oranges, yellows, and green- ‐yellows, and are typicallythought to express warmth, comfort, andenergy.

These colours also tend to make things stand out and advance towards you from the page or screen.

Warm Colours

• Black, grey, and whites are neutral; browns, beiges, and tans are sometimes considered to be neutral as well.

• Neutral colours are intended to send no messages but often work harmoniously with other colours. They are sometimes thought of as colours "off the colour Wheel”

Neutral Colours

• Hue = Pure colour• Tint = Pure colour + white• Shade = Pure colour + black

Hues Tints and Shades

• More visual contrast between a shape• and its background the more weight• the shape will have.

Colour and Design

• Complement of Blue = Yellow

• Complement of Red = Cyan

Bridget Riley

Hexadecimal Colours

• Decimal system0, 1, 2, 3, 4, 5, 6, 7, 8, 9

Ten numbers wriNen in one character space

• Hexadecimal system0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, F

Sixteen numbers wriNen in one character space

Hexadecimal Colours

• Decimal system 10 x 10 = 100

• hexadecimal system F x F = 16 x 16 = 256

Hexadecimal Colours

Hexadecimal Colours

End of Slide