introduction to graphics. terms n computer aided design (cad) –using computer graphics to draft a...
TRANSCRIPT
Introduction to Graphics
Terms
Computer Aided Design (CAD)– using computer graphics to draft a model, can
be tested on screen
Computer Aided Manufacturing (CAM)– integrating the CAD information to determine
the best overall manufacturing procedures
CAD/CAM
Terms
Pixel– Short for “Picture Element”, it is the smallest
unit that appears on the Visual Display Unit
Resolution (解像度 )– the maximum number of pixels that can be disp
layed on a VDU, e.g., 800 x 600
Terms
Bitmap graphics (點陣圖像 )– defines image as a collection of dots (pixels)
– image generally requires more storage space
Terms
Bitmap graphics– used in painting software such as:
• MS Paint, PC Paint Brush, etc.
– scanner, digital camera and fax machine use bitmap graphics to produce/store images
Bitmap Graphics - Example
Smoothnesscannot be maintained when the image is enlarged.
Terms
Vector graphics (向量圖像 )– defines image mathematically as a set of instruc
tions for creating the object in the image
– e.g., rectangle(top, left, bottom, right, line_style, color, …)
(0, 0)
(50, 20)
Terms
Vector graphics– image generally requires less storage space
– used in drawing software such as:• PowerPoint, CorelDraw, etc.
– most clipart images use vector graphic format.
Vector Graphics - Example
As the image is mathematically defined, smoothnesscan be maintained whenthe image is enlarged.
Comparison
Vector Graphics Bitmap Graphics
Object oriented
Less storage space
Less special screen effects
Pixel oriented
More storage space
More special screen effects
Edit pixel individuallyEdit whole object
File Type
Vector Graphics Bitmap Graphics
WMF GIF
JPEG/JPG
BMP
Terms
Object– a component defined in vector graphic software
such as drawings, text, chart and clipart, etc.
Texts
Terms
Attribute (屬性 )– an object’s properties
• i.e., line color, shadow, filled color, etc.
Terms
Handlea small square that appears on the edge when an object is selected
controlling the size of the object
Presentation Graphics
PowerPoint is a presentation graphics software
Enables you to prepare slide presentation
Making Slide Show
opens a new document switches to “Outline” view organises your outlines applies appropriate slide layout applies appropriate slide design
Slide Show Effects
Transition effect– how the slide is changed
Build effect– how the bulleted text and other objects are
shown
Adding Effect
switches to “Slide Sorter” view selects effect from “Transition” tool box selects effect from “Build” tool box if there
are bulleted texts
Adding Custom Effect
PowerPoint also enables you to add custom animation effect to your slide object by right - clicking the object and selects “Custom Animation”.
Inserting Objects
Objects– clipart– chart– graphic image– sound
Menu Command– Insert (插入 ) >> Objects (物件 )
Exporting Graphics Image
PowerPoint supports GIF & JPEG graphics format, you can export your slide(s) by modifying the “File Type” in “Save As…” menu command.
Importing Text
Text can be imported to your slide by executing the following menu commands:– Insert > Object > MS Word Document
When the object shown, executes the following menu commands to import text:– Insert > File
Questions
Give 3 differences between a vector graphics and bitmap graphics software.
Explain why an image created by a low resolution graphics program will normally not be made sharper even if it is imported to a high resolution graphics program.