INTRODUCTION TO
COMPUTERS
LECTURE 4 : WEEK 4
TEXT AND REF. BOOKS
2
Text Book:
Peter Norton (2011), Introduction to Computers, 7 /e, McGraw-Hill
Reference Book:
Gary B (2012), Discovering Computers, 1/e, South Western
Deborah (2013), Understanding Computers, 14/e, Cengage Learning
MOBILE ALERT
Kindly
Switch Off
your Mobile/Cell Phone
OR
Switch it to
Silent Mode
Please
GOOGLE SITE ADDRESS
For Book Download:
https://drive.google.com/file/d/0B-7LjIntmmEHUlVjUG5selpPaEE/view
Presented by: Asma Khan
APPLICATION
SOFTWARE (COMPUTER
GRAPHICS)
Learning Outcome
What Are Computer Graphics Types Of Computer Graphics Raster & Vector Graphics
Types Of Images, Size, Compression & Formats Cartesian Coordinate System
Acquiring Images Graphics Software
What are Computer
Graphics ?
Computer
graphics
are
pictures
created
using
computers
and
the
representation
of
image
data by a computer specifically
with help from specialized graphic
hardware and software
Types of Computer Graphics
Two types of computer graphics
Raster Graphics
Raster graphics are composed of pixels
Uses a grid of individual pixel, each pixel can be a
different color & shade, Commonly called bitmap images
Best used for photographs and images
Is an array of multicolor pixels those form an image
Blocks images because each pixel increases the size of
the image.
Types of Computer Graphics
Vector Graphics
Vector graphics are generated with paths
Use mathematical relationships between points &
the paths connecting them to describe an image
Appear smooth at any size or resolution Every path comprises of lines that may be
straight or curved
Vector graphics can be scaled without losing the
image quality.
Types of Computer Graphics
Jagge d
Smoo th
Types of Images
There are two types of images,
2 Dimensional (2D)
2D is used to create flat digital images X and Y, horizontal and vertical axis
(Length, Width)
2D graphics are used for printing and
Drawing applications
2D graphics are vector based graphics.
Types of Images
3 Dimensional (3D)
3 dimensional representations of geometric
data, such as length, width and depth
Use X, Y and Z axis to represent the image
Cartesian Coordinate System
Coordinate system
that specifies each
point uniquely in a plane by a pair of
numerical
coordinates
The axes in 2D are X and Y
The axes in 3D are X, Y and Z
The origin in 2D is (0,0)
The origin in 3D is (0,0,0)
Image file size is positively correlated to the
number of pixels in an image color depth, or bits per pixel
For example, a 640 * 480 pixel image with 24-bit
color would occupy almost a megabyte of space
640 * 480 * 24 = 7,372,800 bits = 921,600 B
Image File Size
Lossless Compression File size is reduced while preserving a perfect copy of the original uncompressed image
Lossy Compression Algorithms preserve a representation of the original uncompressed image that may appear to be a perfect copy, but it is not
Lossy compression is able to achieve smaller file sizes
than lossless compression
Image File Compression
File formats and compatibility
Method for storing an image
Hundreds of image file formats
Each method has pros and cons
Some formats are proprietary
Graphic software can handle all formats
Separated into the two main families of
graphics: Raster and Vector
Image File Format
JPEG / JFIF
- JPEG2000
EXIF
- TIFF
RAW
- GIF
PNG
- BMP
Raster Formats
JPEG / JFIF
Lossy compression method
Significant reduction of the file size
JPEG (Joint Photographic Experts Group)
compressed images are usually stored in
the JFIF (JPEG File Interchange Format) file format
Filename extension is JPG or JPEG
JPEG files suffer generational degradation when
repeatedly edited and saved
Raster Format
JPEG
JPEG 2000
Compression standard enables both lossless
and lossy storage
Different from the standard JFIF/JPEG
Improve quality and compression
Require more computational power to process
Used currently in professional movie editing
and distribution
Raster Format
Jpeg 2000
EXIF (Exchangeable image file format)
Similar to the JFIF format with TIFF extensions
Record and standardize the exchange of images with
meta data between digital cameras and editing sw
metadata of images include
camera settings, time and date, shutter speed, exposure,
image size, compression, name of camera, color information
Raster Format
TIFF (Tagged Image File Format)
Can be lossy and lossless
Format is not widely supported by web browsers
Widely accepted as a photograph file standard in the printing business
OCR (Optical Character Recognition) software packages commonly generate some form of TIFF
image for scanned text pages
Raster Format
RAW (Raw Image Format)
Available on some digital camera
Usually use a lossless or nearly lossless
compression
File sizes smaller than the TIFF formats
Yet to be standardized or documented
Raster Format
GIF
(Graphics Interchange Format)
Limited to an 8-bit palette, or 256 colors
GIF format suitable for storing graphics with
relatively few colors
Simple diagrams, shapes, logos and
cartoon style images
Format supports animation and is still
widely used
Raster Format
PNG (Portable Network Graphics)
Free, open-source alternative to GIF
PNG file format supports
8 bit paletted images 24 bit truecolor
48 bit truecolor
Designed to work well in online viewing applications
Lossless compression
Raster Format
BMP (Windows Bitmap)
Handles graphics files within the Microsoft
Windows OS
BMP files are uncompressed with simple structure Large size and lossless
Image is drawn using a pixel grid Each grid contains a color
Used to store drawings or photographs Resizing image can reduce quality
Raster Format
USE YOUR BRAIN
USE YOUR BRAIN
29
NOTHING
What is greater than God,
more evil than the devil,
the poor have it,
the rich need it,
USE YOUR BRAIN
30
USE YOUR BRAIN
31
COFFIN
Who makes it, has no need of it.
Who buys it, has no use for it.
Who uses it can neither see nor
feel it.
USE YOUR BRAIN
32
He was wearing his Uniform
A
man
walks
into
a
restaurant, sweating with
BROWN
hairs,
and
the
waiter
says
good
day
Admiral.
USE YOUR BRAIN
33
WINDOW
USE YOUR BRAIN
34
She was walking
A girl who was just learning to
drive went down a one-way
street in the wrong direction,
but didn't break the law.
Most vector formats are proprietary
Three universal formats exist
DXF (Drawing eXchange Format)
IGES (Initial Graphics Exchange Specification)
Both format used by AutoCAD (a software use to
create, modify, analyze or optimize a design) users
Vector File Formats
SVG (Scalable Vector Graphics)
An open standard
Developed by the World Wide Web Consortium
Versatile, scriptable and all-purpose for WWW
No compression scheme
Vector File Formats
Scanners
Like a photocopier
Image is saved onto disk
Scanners import a variety of formats
Ex JPG/JPEG, TIFF, PDF etc
Acquiring Images
Digital cameras
Stores digitized images
Uses long term storage
Image is usually a JPG file
Acquiring Images
Digital video cameras
Stores full motion video
Uses long term storage
Movie can be transferred to
DVD
Acquiring Images
Clip Art
Originally a book with images
Now a CD with images
Most office suites include a
selection
Additional clip art is online
Acquiring Images
Paint programs
Create bitmap images
Includes sophisticated tools
Artists draw with several brushes
Objects drawn become
permanent
Windows Paint
Graphics Software
Draw programs
Create vector based images
Used when accuracy is critical
Objects have an outline and fill
Both have line style and color Can fill using pictures
Adobe Illustrator
Graphics Software
Adobe Illustrator Interface
Photo-Editing software
Modify and manipulate digital images
Work at the pixel level
Images can be enhanced
Picture flaws can be repaired
Pictures can be completely changed
Photoshop and GIMP
Graphics Software
GNU Image Manipulation Program
Computer Aided Drafting (CAD)
Generates vector files
Engineering and design fields
Drawings accurate to the
millimeter
AutoCAD
Graphics Software
3D modeling software
Generates three dimensional images
Image can be shaped on screen
Image is animated frame by frame
AutoCAD, Autodesk 123D, Art of Illusion (Free +
Osource) etc
Graphics Software
Autodesk
Computer generated imaging
Generates photo realistic images
Used for movies and television
Software eliminates tedious parts
Graphics Software
Exercise : PowerPoint
51
Create a Power Point presentation that contains:
Minimum five slides
First slide must contain “Title” of your presentation topic, your
name; roll number, batch and department.
The next slide must contain Introduction about the selected topic Last slide must contain “Conclusion”
Use bullets to include text in the slides Your slides must have slide number.
Make use of Transitions and Slide Layout
Apply an animation effect using the options in the Animation
Any Questions !!!
END OF LECTURE 4
Use YOUR Brain
53
M
Use YOUR Brain
54
STOP IMAGEINING
Use YOUR Brain
55
His Mother
Use YOUR Brain
56
Letter “N”
What happens only in the middle
of each month, in all of the
seasons,
except
Use YOUR Brain
57
Surgeon was His Mother
