This document summarizes scanners and their uses. It describes the main types of scanners as flatbed scanners, hand-held scanners, and optical mark readers. It explains that scanners allow direct data entry from source documents by translating paper into electronic format. Scanners are useful for preserving documents electronically, allowing manipulation of images. While scanners improve data accuracy over manual entry, they require high quality source documents.

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