Institute for Visualization and Perception Research 1 © Copyright 2000 Haim Levkowitz Introduction...
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Transcript of Institute for Visualization and Perception Research 1 © Copyright 2000 Haim Levkowitz Introduction...
Institute for Visualization and Perception ResearchIVPR 1
© Copyright 2000 Haim Levkowitz
Introduction (Foley & Van Dam Ch 1)
• Uses of computer graphics …
• Some basic terms and concepts …
• Image processing and synthesis …
• Classification of applications …
• HW & SW for computer graphics …
• Advantages of interactive graphics …
• Conceptual framework for interactive graphics ...
Institute for Visualization and Perception ResearchIVPR 2
© Copyright 2000 Haim Levkowitz
Uses of Computer Graphics …
• User interfaces• Interactive plotting: business, science, technology, art• Cartography• Medicine• Computer-aided drafting and design• Multimedia systems• Simulation, animation, visualization• Office automation and electronic publishing
Institute for Visualization and Perception ResearchIVPR 3
© Copyright 2000 Haim Levkowitz
Some Basic Terms and Concepts …
• Interactive
• Bitmap
• Bitmap graphics
• Pixels, pels
• Windows, window manager
• Direct manipulation
Institute for Visualization and Perception ResearchIVPR 4
© Copyright 2000 Haim Levkowitz
Image Processing & Synthesis …• Synthesis
• Image processing
• Picture processing
• Reconstruction of processing
• Image enhancement
• Pattern detection and recognition
• Scene analysis and computer vision
• Optical Character Recognition (OCR)
generate initial display from modeldo {
enable selection of commands or objectswait for user selection /* Wait state */switch (on selection) {
process selectionupdate model and screen
}}while (!quit)
Institute for Visualization and Perception ResearchIVPR 5
© Copyright 2000 Haim Levkowitz
Classification of Applications …
• Dimensionality of object & kind of picture …
• Type of interaction
• Offline plotting
• Interactive plotting
• Role of the picture
Institute for Visualization and Perception ResearchIVPR 6
© Copyright 2000 Haim Levkowitz
Dimensionality of object & kind of picture
• 2D
• Line drawing
• Gray scale image
• Color image
• 3D
• Line drawing (wireframe)
• Line drawing, with various effects
• Shaded, color image with various effects
Institute for Visualization and Perception ResearchIVPR 7
© Copyright 2000 Haim Levkowitz
HW & SW for Computer Graphics …
• Large, interactive programs
• Nonportable vs. portable software
• Output technology …
• Input technology …
• Software portability and graphics standards ...
Institute for Visualization and Perception ResearchIVPR 8
© Copyright 2000 Haim Levkowitz
Output technology
• Vector …
• Raster displays ...
Institute for Visualization and Perception ResearchIVPR 9
© Copyright 2000 Haim Levkowitz
Vector …• Stroke, line drawing,
calligraphic displays• Characters• Display list, display program• Vector generator• Random scan• Refresh• Refresh buffer
Institute for Visualization and Perception ResearchIVPR 10
© Copyright 2000 Haim Levkowitz
Raster displays …
• Primitives
• Raster lines
• Raster ...
• Bitmap, pixmap
• Frame buffer
• Scan-converted
• Raster image processor
• Aliasing, antialiasing
Institute for Visualization and Perception ResearchIVPR 11
© Copyright 2000 Haim Levkowitz
RasterVector vs. raster ...
Institute for Visualization and Perception ResearchIVPR 12
© Copyright 2000 Haim Levkowitz
Vector vs. raster
Institute for Visualization and Perception ResearchIVPR 13
© Copyright 2000 Haim Levkowitz
Input technology …
• Text: Keyboard
• Locator: Pointer / Mouse / Tablet
• Higher dimensions
• Polhemus
• Spaceball
Institute for Visualization and Perception ResearchIVPR 14
© Copyright 2000 Haim Levkowitz
Software portability and graphics standards ...
• Device-independent
• Application-program portability
• Device-dependent
• Core Graphics System
• Segments
• Structures
Institute for Visualization and Perception ResearchIVPR 15
© Copyright 2000 Haim Levkowitz
The advantages of interactive graphics …
• Motion dynamics
• Update dynamics
Institute for Visualization and Perception ResearchIVPR 16
© Copyright 2000 Haim Levkowitz
Conceptual framework for interactive graphics …
• Overview …
• Modeling …
• Display …
• Interaction Handling …
Institute for Visualization and Perception ResearchIVPR 17
© Copyright 2000 Haim Levkowitz
Overview
• Application program
• Application model
• Graphics system
• What
• How
• Output transformation
• Input transformation
Institute for Visualization and Perception ResearchIVPR 18
© Copyright 2000 Haim Levkowitz
Modeling …
• Application model
• Application database
• Primitives
• Attributes
• Connectivity
• Geometrical interpretation
Institute for Visualization and Perception ResearchIVPR 19
© Copyright 2000 Haim Levkowitz
Display …
• Graphics subroutine library or package
• Logical display device
• Locator
• Sample vs. event
Institute for Visualization and Perception ResearchIVPR 20
© Copyright 2000 Haim Levkowitz
Interaction Handling …
• Event-driven loop