Lecture 34: Intelligent Systems - Computer Graphics, Pixels, Colors, Slides of Introduction to Computing

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CS101 Introduction to Computing

Lecture 34

Intelligent Systems

During the last lecture … (Graphics & Animation)

• We became familiar with the role that graphics and animations play in computing
• We discussed how graphics & animation are displayed
• We also looked at several formats used for storing graphics and animation

Displaying Images

• Most all computer displays consist of a grid of tiny pixels arranged in a regular grid of rows and columns
• Images are displayed by assigning different colors to the pixels located in the desired portion of the computer display
• Let’s discuss the pixel a bit more …

Pixel

• The smallest image forming element on a computer display
• The computer display is made up of a regular grid of these pixels
• The computer has the capability of assigning any color to any of the individual pixels on the display
• Let’s now see how the computer displays a square

Color Mapping (1)

• Instead of letting each pixel assume one out of 16 million possible colors, only a limited number of colors – called the platelet – are allowed
• For example, the platelet may be restricted to 256 colors (requiring 1 byte/pixel instead of 3)

Dithering

• In this scheme, pixels of alternating colors are used to simulate a color that is not present in the platelet
• For example, red and green pixels can be alternated to give the impression of bright yellow
• The quality of the displayed image is poorer

Anti-Aliasing (1)

• Anti-aliasing is another technique used for managing the ‘staircase’ effect
• Let’s say that we need to draw a white straight-line such that it overlaps 60% with one pixel, and 40% with another initially, and near the end, 58%, 41%, and 1%, respectively, with three pixels

Vector or Object-Oriented Graphics

• Treats everything that is drawn as an object
• Objects retain their identity after they are drawn
• These objects can later be easily moved, stretched, duplicated, deleted, etc
• Are resolution independent
• Relatively small file size
• Examples: swf, svg, wmf, ps (^) Docsity.com 11

3-D Graphics (1)

• Flat images enhanced to impart the illusion of depth
• We perceive the world and the objects in it in 3-D - breadth, width, depth - although the images formed on the retinas of our eyes are 2-D
• The secret of 3-D perception: stereo vision

3-D Rendering

• The process of converting information about 3-D objects into a bit-map that can be displayed on a 2- D computer display
• Computationally, very expensive!
• Steps:
  • Draw the wire-frame (skeleton, made with thin lines)
  • Fill with colors, textures, patterns
  • Add lighting effects (reflections, shadows) (^) Docsity.com 14

Tweening (2)

• This process of creating these in-between images from key images is called in-betweening (or tweening for short)
• The simplest algorithm for tweening calculates the position of a particular segment of an image by calculating the average of the positions of that same image segment belonging to adjacent key images

Today’s Goals: (Intelligent Systems)

• To become familiar with the distinguishing features of intelligent systems with respect to other software systems
• To become able to appreciate the role of intelligent systems in scientific, business and consumer applications
• To look at several techniques for designing intelligent systems

Not a Suitable Hammer for All Nails!

if the nature of computations required in a task

is not well understood

or there are too many exceptions to the rules

or known algorithms are too complex or inefficient

then AI has the potential of offering an

acceptable solution (^) Docsity.com^19

Selected Applications

• Games: Chess, SimCity
• Image recognition
• Medical diagnosis
• Robots
• Business intelligence