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Lesson 6Images

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Overview

• Creation of multimedia images.

• Creation of still images.

• Colors and palettes in multimedia.

• Image file types used in multimedia.

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Creation of Multimedia Images

Before commencing the creation of images in Multimedia, one should:

• Plan their approach using flow charts and storyboards.

• Organize the available tools.

• Have multiple monitors, if possible, for lots of screen real estate.

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Creation of Still Images

• Still images may be the most important element of a multimedia project.

• The type of still images created depends on the display resolution, and hardware and software capabilities.

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Creation of Still Images

1) Types of still images:

a. Bitmaps:

• Bitmap is derived from the words ‘bit’, which means the simplest element in which only two digits are used, and ‘map’, which is a two-dimensional matrix of these bits.

• A bitmap is a data matrix describing the individual dots of an image.

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Bitmaps

Bitmaps are an image format suited for creation of:

• Photo-realistic images.

• Complex drawings.

• Images that require fine detail.

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Bitmaps

• Bitmapped images are known as paint graphics.

• A bitmap is made up of individual dots or picture elements known as pixels or pels.

• Bitmapped images can have varying bit and color depths.

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Bitmaps

Available binary Combinations for Describing a Color

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Bitmaps

Figure 6-1A bitmap is a data matrix that describes the characteristics of

all the pixel making up an image. Here, each cube represents the data required to display a 4x4-pixel image (the face of the cube)

at various color depths (with each cube extending behind the face indicating the number of bits-zeros or ones-used to

represent the color for that pixel).

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Figure 6-2These images show the

color depth of bitmaps as described in figure 6-1.

Note that images 4 and 6 require the same

memory (same file size), but the gray-scale image is superior. Because file size (download time) is important for images

that are displayed on the Web, designers often

dither GIF bitmap files to the lowest color depth that will still provide an

acceptable image.

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Bitmaps

Bitmaps can be inserted by:

i. Using clip art galleries:

• A clip art gallery is an assortment of graphics, photographs, sound, and video.

• Clip arts are a popular alternative for users who do not want to create their own images.

• Clip arts are available on CD-ROMs and on the Internet.

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Figure 6-3A page of

thumbnails showing the content of

various PhotoDisc CD-ROMs.

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Bitmaps

Bitmaps can be inserted by(continued):

ii. Using bitmap software:

• The industry standard for bitmap painting and editing programs are:

Adobe's Photoshop and Illustrator.

Macromedia's Fireworks.

Corel's Painter.

CorelDraw.

Quark Express.

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Figure 6-4The Windows Paint accessory provides

rudimentary bitmap editing.

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Figure 6-5Director, like most serious multimedia authoring packages,

includes powerful image-editing tools.

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Figure 6-6Fireworks provide tools for bitmap and vector graphics destined for Web presentations.

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Figure 6-7Painter is used for creating original artwork; for book, medical,

and architectural illustration; to transform photographs into realistic-looking paintings; to build seamless patterns for

fabrics; and for storyboarding scene concepts and customers for movies and theater.

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Bitmaps

Bitmaps can be inserted by(continued):

iii. Capturing and editing images:

• Capturing and storing images directly from the screen is another way to assemble images for multimedia.

• The PRINT SCREEN button in Windows and COMMAND-CONTROL-SHIFT-4 keystroke on the Macintosh copies the screen image to the clipboard.

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Figure 6-8Image-editing programs

let you add and delete elements.

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Bitmaps

Bitmaps can be inserted by(continued):

iii. Capturing and editing images:

• Image editing programs enable the user to:

Enhance and make composite images.

Alter and distort images.

Add and delete elements.

Morph (manipulate still images to create animated transformations).

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Figure 6-9Morphing

software was used to

seamlessly transform the images of 16

kindergartners. When a sound track of music and voice was added to the four-minute

piece, it made a compelling QuickTime video about how similar

children are to each other.

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Bitmaps

Bitmaps can be inserted by(continued):

iv. Scanning images:

• Users can scan images from conventional sources and make necessary alterations and manipulations.

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Creation of Still Images

1) Types of still images(continued):

b. Vector-drawn graphics:

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Vector-Drawn Graphics

b.1. Applications of vector-drawn images:

• Vector-drawn images are used in the following areas:

Computer-aided design (CAD) programs.

Graphic artists designing for the print media.

3-D animation programs.

Applications requiring drawing of graphic shapes.

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Vector-Drawn Graphics

b.2. How vector-drawn images work:

• A vector is a line that is described by the location of its two endpoints.

• Vector drawing makes use of Cartesian co-ordinates.

• Cartesian coordinates are numbers that describe a point in two or three-dimensional space as the intersection of X, Y, and Z axis.

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Vector-Drawn Graphics

b.3. Vector-drawn images v/s bitmaps:

• Vector images use less memory space and have a smaller file size as compared to bitmaps.

• For the Web, pages that use vector graphics in plug-ins download faster, and when used for animation, draw faster than bitmaps.

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Vector-Drawn Graphics

b.3. Vector-drawn images v/s bitmaps (continued):

• Vector images cannot be used for photorealistic images.

• Vector images require a plug-in for Web-based display.

• Bitmaps are not easily scalable and resizable.

• Bitmaps can be converted to vector images using autotracing.

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Creation of Still Images

2) 3-D drawing and rendering:

3-D animation, drawing, and rendering tools include:

• Ray Dream Designer.

• Caligari True Space 2.

• Specular Infini-D.

• Form*Z.

• NewTek's Lightwave.

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3-D Drawing and Rendering

b. Features of a 3-D application:

• Modeling - Placing all the elements into 3-D space.

• Extrusion - The shape of a plane surface extends some

distance.

• Lathing - A profile of the shape is rotated around a

defined axis.

• Rendering - Use of intricate algorithms to apply user-

specified effects.

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Figure 6-103-D applications

provide x, y, and z axes and adjustable

perspective views.

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3-D Drawing and Rendering

c. Panoramas:

• Panoramic images are created by stitching together a sequence of photos around a circle and adjusting them into a single seamless bitmap.

• Software such as ULead Cool 360, and Panorama Factory are required in order to create panoramas.

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Figure 6-11A chair modeled in

Infini-D is made up of various blocks and

rectangles.

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Figure 6-12A free-form object created by

extrusion and a wine flute created by lathing.

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Figure 6-13A scene

rendered with four different

methods of shading.

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Figure 6-14A background

and object rendered into an

image with shadows and

lighting effects.

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Colors and Palettes in Multimedia

1. Understanding natural light and color:

• Light comes from an atom where an electron passes from a higher to a lower energy level.

• Each atom produces uniquely specific colors.

• Color is the frequency of a light wave within the narrow band of the electromagnetic spectrum, to which the human eye responds.

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Figure 6-15Color pickers allow you to select

a color using one or more different models of color space.

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Understanding Natural Light and Color

1. Additive color:

• In the additive color method, a color is created by combining colored light sources in three primary colors - red, green, and blue (RGB).

• TV and computer monitors use this method.

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Understanding Natural Light and Color

2. Subtractive color:

• In the subtractive color method, color is created by combining colored media such as paints or ink.

• The colored media absorb (or subtract) some parts of the color spectrum of light and reflect the others back to the eye.

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2. Subtractive color(continued):

• Subtractive color is the process used to create color in printing.

• The printed page consists of tiny halftone dots of three primary colors- cyan, magenta, and yellow (CMY).

Understanding Natural Light and Color

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Understanding Natural Light and Color

3. Monitor-specific color:

• Colors should be used according to the target audience's monitor specifications.

• The preferred monitor resolution is 800x600 pixels.

• The preferred color depth is 32 bits.

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Understanding Natural Light and Color

4. Color models:

Models used to specify color in computer Terms are:

• RGB model - A 24-bit methodology where color is specified in terms of red, green, and blue values ranging from 0 to 255.

• HSB and HSL models – Color is specified as an angle from 0 to 360 degrees on a color wheel.

• Other models include CMYK, CIE, YIQ, YUV, and YCC.

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Colors Palettes

• Palettes are mathematical tables that define the color of pixels displayed on the screen.

• Palettes are called ‘color lookup tables’ or CLUTs on Macintosh.

• The most common palettes are 1, 4, 8, 16, and 24-bit deep.

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Figure 6-16These palettes of 256 colors (8-bit color depth) are provided in

Macromedia’s Director.

Images saved in the popular

GIF format for use on the Web cannot contain more

than 256 colors.

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Colors Palettes

Dithering:

• Dithering is a process whereby the color value of each pixel is changed to the closest matching color value in the target palette.

• This is done using a mathematical algorithm.

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Figure 6-17These images were dithered in Photoshop to best fit the 8-bit palettes of GIF files (Adaptive,

System, or Custom 216 Netscape). Also shown are JPEG files compressed with

highest and lowest quality and their actual file sizes. The files

were then displayed using Netscape Navigator at 16-bit

and then 8-bit color depth. Note the subtle differences among

palettes and systems, especially in the gradient blue

background. Gradients do not usually dither well into 8-bit

palettes.

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Image File Types used in Multimedia

1. Macintosh formats:

• On the Macintosh, the most commonly used

format is PICT.

• PICT is a complicated and versatile format

developed by Apple.

• Almost every image application on the

Macintosh can import or export PICT files.

• In a PICT file, both vector-drawn objects and

bitmaps can reside side-by-side.

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Image File Types used in Multimedia

2. Windows formats:

• The most commonly used image file format on Windows is DIB.

• DIB stands for Device-independent bitmaps.

• The preferred file type for multimedia developers in Windows is Resource Interchange File Format (RIFF).

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2. Windows formats(continued):

• Bitmap formats used most often by Windows developers are:

BMP - A Windows bitmap file.

TIFF - Extensively used in DTP packages.

PCX - Used by MS-DOS paint software.

Image File Types used in Multimedia

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Image File Types used in Multimedia

3. Cross-platform formats:

• The image file formats that are compatible across platforms are:

DXF - Used by CAD applications.

Initial Graphics Exchange Standard (IGS or IGES) - Standard for transferring CAD drawings.

JPEG and GIF - Most commonly used formats on the Web.

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Summary• The computer generates still images as bitmaps

and vector-drawn images.

• Images can be incorporated in multimedia using clip arts, bitmap software, or by capturing, editing, or scanning images.

• Creating 3-D images involves modeling, extruding, lathing, shading, and rendering.

• Color is one of the most vital components of multimedia.