introduction to computer graphics l.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Introduction to Computer Graphics PowerPoint Presentation
Download Presentation
Introduction to Computer Graphics

Loading in 2 Seconds...

play fullscreen
1 / 20

Introduction to Computer Graphics - PowerPoint PPT Presentation


  • 120 Views
  • Uploaded on

Introduction to Computer Graphics. COMP 3003. Recommended Reading. Computer Graphics – Principles and Practice Foley, Van Dam, Feiner, Huges Computer Graphics D. Hearn, M. P. Baker 3D Computer Graphics Alan Watt Computer Graphics F.S. Hill, JR. Fundamentals of Digital Image Processing

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Introduction to Computer Graphics' - giovanna


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
recommended reading
Recommended Reading
  • Computer Graphics – Principles and Practice
    • Foley, Van Dam, Feiner, Huges
  • Computer Graphics
    • D. Hearn, M. P. Baker
  • 3D Computer Graphics
    • Alan Watt
  • Computer Graphics
    • F.S. Hill, JR.
  • Fundamentals of Digital Image Processing
    • Anil K. Jain
course overview
Course Overview
  • Hardware, Input & Output - Display Technology
  • The Eye and image perception
  • Colours & Colour Models
  • Object Modelling
  • 2D Viewing - Windows and Viewports
  • Transformations - Matrix Representation
  • Bezier Curves
  • Clipping
  • 3D Graphics
  • Image Compression - JPEG, MPEG, GIF etc.
  • VRML and the WEB
contact details
Contact Details
  • Michela Bertolotto
  • Room B2.21
  • Email : michela.bertolotto@ucd.ie
  • Web pages (see www.cs.ucd.ie)
    • Lecture Notes & Handouts
hardware issues input technology
Hardware Issues (Input Technology)
  • Pieces of hardware by which a user enters information into a computer system
    • mouse, trackball, joystick, voice systems, touch screens etc.
hardware issues digital camera input
Hardware Issues (Digital Camera Input)
  • Cameras
    • The image is focused onto a photosensitive surface (such asa charge coupled device (CCD)) line by line to accumulate entire image
  • The CCD produces current (or simply digital output in newer systems) which is proportional to light intensity (filtered for each of three colour bands)
  • Different quality/functionality cameras are used:Monochrome, Colour, Smart ( Designed for machine vision applications )
virtual reality and voice recognition
Virtual Reality and Voice Recognition
  • Virtual reality has generated a completely new set of input devices
    • Dataglove
    • Pressure pads
    • Digitizing arm
    • Various other tactile and gesture input device
  • Much research is currently in progress to devise better ways of interacting with the machine
  • Voice recognition and natural language comprehension are also currently the focus of much research
hardware issues input technology12
Hardware Issues (Input Technology)
  • A major goal in designing graphics packages is device-independence
    • enhances portability of the application
  • To provide a level of abstraction for graphics input, most graphics systems support logical input devices
  • These shield the application from the details of the physical devices available
logical input devices
Logical Input Devices
  • Locator
    • to indicate a position or orientation
  • Pick
    • selects from a displayed entity
  • Valuator
    • to input a single real number (Volume Control Dial)
  • Keyboard
    • to input a character string
  • Choice
    • to select from a set of possible actions or choices (Function Keys)
logical input devices14
Logical Input Devices
  • Locator:
    • Inputs a position (x,y) typically via pointer (mouse/joystick)
  • Pick:
    • Identifies a displayed object NOT just an (x,y).
      • Selects a whole object that is normally associated with a segment via e.g. a lightpen
  • Choice:
    • Selects from a set of alternatives:
      • i.e. integer value from buttons on a box or via a menu selection with lightpen or digitiser, most common is function keys
  • Valuator:
    • Inputs a value (real or integer) perhaps from a dial (can be bounded – radio tuner or unbounded – provides relative info.)
locator input devices
Locator Input Devices
  • Absolute or Relative
    • Absolute: report position with regard to an origin
      • e.g. data tablet, touch screen
    • Relative: report position w.r.t. their former position
      • e.g. mouse, joystick
  • Direct or Indirect
    • Direct: user points directly at screen
      • e.g. light-pen or finger on touch screen
    • Indirect: user moves cursor on screen with device not on screen
      • e.g. mouse or joystick
locator input devices cont
Locator Input Devices (cont)
  • Discrete or Continuous
    • Continuous: smooth hand motion
      • e.g. mouse, trackball
    • Discrete: define action
      • e.g. cursor-control keys
hardware issues display technology
Hardware Issues (Display Technology)
  • Different outputdevices may be used - monitors, printers, plotters
  • Most common is the Cathode Ray Tube (CRT) monitor
    • Horizontal and vertical deflectors focus an electron beam emitted by an electron gun on any spot on a phosphor coated screen
    • The maximum number of points, or pixels that can be displayed without overlap is called the resolution, e.g. 1024x768, 800x600 etc.
    • Colour systems have groups of 3 different phosphors, for red, green and blue (the primary colours)
    • The CRT uses a combination of these phosphors to emit different coloured light
phosphors
Phosphors
  • Once struck by the electron beam most phosphors relax back to the ground state by emitting a photon of light
  • This light is called fluorescence, which normally decays in under a millisecond
  • Some molecules may be further excited, and emit a light call phosphorescence, which decays slower, but still rapidly (15-20 milliseconds)
  • Therefore, the screen must be refreshed by redrawing the image
phosphors19
Phosphors
  • So phosphors may be characterised by their persistence
    • (time to decay of emitted light)
  • High persistence cheap and good for text, bad for animation (original IBM PC monitor)
  • Low persistence, good for animation, but needs a high refresh rate or flicker can be observed
  • 50-60 Hz is usually sufficient to avoid flicker