a complete ready to present presentation on scanners its types,uesage,limitations and advantages

1. UNIVERSITY OF WAH
COMPUTER GRAPHICS
PRESENTATION TOPIC:
SCANNERS
PRESENTED BY:
ZEESHAN HANIF
PRESENTED TO:
SIR MUHAMMAD SARDARAZ

2. CONTENTS---
 Introduction to scanners.
 Types of scanners –
I. Flatbed scanner.
II. Hand-held scanner.
III. Optical mark reader.
 Working of scanners
 Usage
 Limitation of image scanners.

4. Scanners are input devices
which allow data entry from
source document directly.

5.  It is an input device, translates paper
document into electronic format, as an input
to a computer.
 Input can be type, text, pictures, even
handwritten material also.
 Useful for preserving paper documents, a
document stored in computer does not
deteriorate in quality with age.
 It can be printed or displayed whenever
required. We can also alter and manipulate
the stored images.

6.  Eliminate manual entry of data , thus
improves data accuracy.
 Automatic entry of data with their use
improves data accuracy , increase timeliness
of information processed.
 Demand high quality source document ,
rejects-poorly typed documents or strikeover
documents or documents having erasures.
 Form design and ink specification is more
critical with the use of these devices as
compare to keyboard for data entry.

7. Types of scanner---
FLATBED SCANNER
HAND-HELD SCANNER

8.  It is like a copier machine.
 Consist of a box having a
glass plate on its top, lid
that covers a glass plate.
 Activated glass plate moves
horizontally from one end
to another.
 After scanning one line,
light beam moves up a little
to scan other line , process
continues till the scanning
finishes.
 Takes 20 seconds to scan a
document of 21*28 cm in
size.
 They are costly as compare
to hand-held scanner.
 User can hold them in hand
conveniently.
 It has a case of light
emitting diodes incased in a
small case.
 For scanning, user drags it
slowly from one end to
other of a document when
its light is on.
 User must drag it slowly and
smoothly for the correct
conversion of document to
its equivalent bit map.
 User use them when they
have less number of
documents.
 They are cheaper than
flatbed scanner.

9.  Place pictures on the scanner glass
 Start scanner software
 Select the area to be scanned
 Choose the image types
 Sharp the images
 Set the image size
 Save the scanned images

10.  It is a scanner , which recognize pre-
specified type of mark made by pencil or
pen.
 The technique used by OMR devices for
recognition of marks on document involves
Focusing a light beam on the document and
detecting the reflected light pattern from
the marks.

11.  If a document stored in the computer as an
image instead of text , than it is not possible
to do any word processing.
 Storage space required for storing the
document as an image is much more than
that required for storing a text document.

12.  To reduce the time spent on data input.
 To capture pictures, photo , drawing or
graphics directly.
 To save images for future use.
 More efficiency
 Reliable
 Accurate