LECTURE 6: WORKING WITH DIGITAL IMAGE EVI INDRIASARI MANSOR Tel ext:

Outline  Creating Digital Images  Painting Program  Editing Digital Images  Drawing with Lines, Curves, and Objects  3D Graphics  Animation 2

Learning Outcomes  Able to explain various aspects of 3-D modeling  Able to use colors and palettes in multimedia  Able to discuss the various file types used in multimedia 3

Based on material from Exploring the Digital Domain: An Introduction to Computers and Information Fluency (2 nd Edition) Published by Brooks/Cole, 2004 © 2004 Ken Abernethy & Tom Allen 4

Creating Digital Images  Before commencing the creation of images in Multimedia, one should  Plan their approach using flow charts and storyboards  Organize the available tools 5

Creating Digital Images (cont)  Graphic Image Development  Still images are classified in two types of technology: natural graphic artificial graphic 6

Creating Digital Images (cont)  Graphic Image Development  Natural graphic In the world external to the computer (original analog image) types of natural graphic: Pictures of people, places and things – drawn images photographs Diagrams of building (floor plans) and blueprint Charts and graphs – figures depicted through lines, curves and color Categorize as raster-based graphic or bitmap image Composed of a matrix of elements called pixels – picture elements in digital images 7

Creating Digital Images (cont)  Graphic Image Development  Artificial graphic Created exclusively by computer processes – graphic images – 2D and 3D images Type of artificial graphic: 2D graphic 3D graphic The quality based on duplicating of ‘look and feel’ of the images Categorize as vector-based graphic or metafile image Express mathematical formula in angles, coordinates, and distance Based on basic drawing elements or objects to create an image – lines, rectangles, oval, polygons 8

Painting Program  Blend 2-D bit-mapped graphics with an interface that mimics brush and canvas techniques used by a painter  Typical painting program interface divides the workspace into:  Palettes – selection of tools, patterns, textures and colours that may be applied to the images contained within a canvas  Menus – stores commands and features that may selected by users  Canvas – window that reveals at least part of bit- mapped image that has been created or opened from an existing file 9

Painting Program (cont)  The image and the image canvas  The size and resolution for painting program usually fixed – need to be determined it first, later the modification and control only on its contents but not always its size or resolution  Image size – the actual extent of the image  Picture resolution – specifies the number of pixels used  Image scale – the relative size of the image displayed compared to actual size  Canvas divided into two layers – foreground and background 10

Painting Program (cont)  Painting Tools and Features  Most paint programs equipped with common array of tools used for drawing, painting and organised one or more palettes – user can select the appropriate tools and applies to the canvas  Typical painting and drawing tools: Pencil, Airbrush, Crayon, Felt pen, Charcoal Eraser Palettes for patterns, colours, textures 11

Editing and Special Effects  Select and modify image components (a) A rectangular area surrounding the circle is selected for editing the circle (b) The selected area is moved. The white background is revealed when the foreground pixels are moved (c & d) the area of the circle is selected with better precision. 12

Editing and Special Effects  Transformation 13 Lighting effects Rotate shadow

Drawing with Lines, Curves and Objects  Computer could used to create graphic image in a convenient manner  Object oriented graphics – tools for manipulating the object - the program freed the user from the messy details of how the image graphic were defined, formed and displayed  In the world of object-oriented (or vector) graphics, pixels are replaced by elements such as lines, curves, paths and figures 14

Drawing with Lines, Curves and Objects  Object oriented graphics offers several distinct advantages over bit-mapped approaches  Object oriented graphics is more abstract The user is freed from the details of how the the computer system stores and displays an image Entities such as lines and curves are more intuitive  Object oriented are resolution independent The images are defined abstractly - adapted to fit various resolution and can be fitted easily to a variety of devices 15

Drawing with Lines, Curves and Objects  Vector graphic applications offer features with greater power and flexibility A graphic object is specified by its attributes such as dimensions, position in the image, patterns etc.. E.g. moving an object from one location to another is a simple matter of modifying the description of its position coordinates 16

Drawing with Lines, Curves and Objects  Drawing Programs  Best suited for simpler types of illustrations and charts  There are tools for drawing lines, arcs and figures such as rectangles, ovals and circles  Once the lines, arcs are drawn, the differences between painting and drawing programs become a lot more apparent E.g. when the object is selected, usually displayed with a special tools called handles – used for resizing the object 17

Drawing with Lines, Curves and Objects  Drawing Curves  Drawing programs incorporate – parametric curves (based on mathematical equations)  The users draws the curve by specifying a set of points that it passes through 18

Drawing with Lines, Curves and Objects  Drawing with Image Layers  Each object occupies its own layer – stamped on a transparent background  The order of layers dictates what and how much of the image’s objects are visible 19

Drawing with Lines, Curves and Objects  Illustration Programs  Are intended for professionals rather than casual users  Produce high quality output necessary for professional publication  Illustration program usually present different views of their graphics images This views make it easier to see the actual structure of the image 20

3D Graphics  3D Drawing and Rendering  3D graphics tools – Macromedia Extreme3D, or Form-Z,  Extend vector-drawn graphics in 3 dimensions (x, y and z) 21 X y Z

3D Graphics 22

3D Graphics (cont)  3D Drawing and Rendering (cont)  A 3D scene – consist of object that in turn contain many small elements, such as blocks, cylinders, spheres or cones (described in terms of vector graphics)  The more elements, the finer the object’s resolution and smoothness 23

3D Graphics (cont)  3D Drawing and Rendering (cont)  Objects as a whole have properties such as shape, color, texture, shading & location  A 3D application lets you model an object’s shape, then render it completely 24

3D Graphics (cont)  Features of 3D Application (cont)  Modeling - involves drawing a shape, such as a 2D letter, then extruding it or lathing it into a third dimension: extruding : extending its shape along a defined path lathing : rotating a profile of the shape around a defined axis 25

3D Graphics (cont)  Features of 3D Application (cont)  Modeling also deals with Lighting Setting a camera view to project shadows 26

3D Graphics (cont)  Features of 3D Application (cont)  Rendering - produces a final output of a scene and is more compute-intensive 27

3D Graphics (cont)  3D Animation Tools  3-D animation, drawing, and rendering tools include: Ray Dream Designer Caligari True Space 2 Specular Infini-D Form*Z NewTek's Lightwave 28

Animation  Animation creates an illusion of motion by displaying a sequence of changes images in rapid succession  If the images – called frames – are displayed at fast enough rate – person perceives them as depicting motion  Usually rates of 15 or 16 frames per second (fps) to produce sufficient illusion  Professional quality – 24 fps and higher 29

Animation (cont)  Animation films tell a story which describe the action of the film  Story comprise scenes (a specific set of object at a given location)  The story is often depicted scene by scene in a series of drawings that make up the storyboard  Three classes of Digital animation applications:  Object animation  Modeling animation  Authoring animation systems 30

Animation (cont)  Object animation Usually based on 2D graphic images The user draws or assembles key frames The program then calculates and produces the in- between (normally based on starting and ending key frames with a user defined path to track the intended motion between them) User may choose objects from a standard library or create new ones 31

Animation (cont)  Modeling animation Automate the process of manipulating a rendered object in 3D- space The animator defines the objects as 3D models The program creates an animation based on manipulating the model with a virtual camera that captures the scene 32

Animation (cont)  Authoring animation systems Some systems are designed to automate the process of animation from storyboard to finished product In an authoring system, the users creates a storyboard that specifies the sequencing of scenes for the animation Objects are defined within each scene Each scenes is scripted: motions, reactions and interactions In addition visual effects may be chosen for transitions between scenes Authoring systems produce multimedia presentations (combination of images, sound and interaction) – used to create interactive, animated application for entertainment and education 33

Summary  Painting, drawing and illustration are 2D graphic programs – the images are created, stored and displayed as 2D images  3D graphic application program allow the user to define and manipulate objects in stimulated 3D  Creating 3D images involves modeling, extruding, lathing, shading and rendering  Animation program provides tools for automating the process of developing frames used in computer animations 34