Upload
others
View
0
Download
0
Embed Size (px)
Citation preview
A Introduction to Scanning
Lowell Williamson AHS Computing March 18, 2005
An Introduction to Scanning 2 AHS Computing
Overview
Types of images
Scanning Pictures
Manipulating Pictures
Scanning Text
Location of files
An Introduction to Scanning 3 AHS Computing
HP Director Software
The HP Director Software allows the user to ‘direct’ themselves to the application that is appropriate for them
An Introduction to Scanning 4 AHS Computing
How to start a scan?
Most scanners have buttons on the front that will invoke an associated application
The standard buttons include
– Scan a picture
– Scan a document
– Make a copy
– Scan to email
Startup the application from the menus
An Introduction to Scanning 5 AHS Computing
What are you scanning?
It makes a difference what kind of scan you are performing
Different levels of resolution are required for different types of scanning
An Introduction to Scanning 6 AHS Computing
Preview the scan
Scanning software will allow you to preview your scan before saving it to a file
It is at this point you will have an opportunity to adjust resolution, output type, rotation, size etc. before saving the file
An Introduction to Scanning 7 AHS Computing
Types of Images
Bitmap
– The standard bit-mapped graphics format used in the Windows environment. By convention, graphics files in the BMP format end with a.BMP extension.
Jpeg
– file extension for JPEG (Joint Photographic Experts Group). A file stored in JPEG format. JPEG,an ISO/ITU standard for storing images with high compression capability, uses a discreet cosine transform that can achieve compression rates of 100:1 (significant loss of data from original) and 20:1 (minimal loss).
An Introduction to Scanning 8 AHS Computing
Types of Images
Tiff – Acronym for tagged image file format, one of the most
widely supported file formats for storing bit-mapped images on personal computers (both PCs and Macintosh computers). TIFF graphics can be any resolution, and they can be black and white, gray-scaled, or color. Files in TIFF format often end with a .tif extension.
Gif – Pronounced jiff or giff (hard g) stands for graphics interchange format, a bit-mapped graphics file format used by the World Wide Web, CompuServe and many BBSs. GIF supports color and various resolutions. It also includes data compression, but because it is limited to 256 colors, it is more effective for scanned images such as illustrations rather than color photos.
http://www.webopedia.com/
An Introduction to Scanning 9 AHS Computing
DPI = Resolution
The term dpi means Dots Per Inch, referring to image "pixels per inch" (but printer dpi is different than image dpi).
The meaning of scanned dpi is that if you scan a 6x4 inch photo at 110 dpi, then you will necessarily get an image size of :
(6 inches x 110 dpi) x (4 inches x 110 dpi) = 660 x 440 pixels
– which more or less totally fills a 640x480 monitor screen.
Or scanning the 6x4 inch photo at 140 dpi gives (6 inches x 140 dpi) x (4 inches x 140 dpi) = 840 x
560 pixels – which more or less totally fills a 800x600 monitor screen.
Or scanning the 6x4 inch photo at 180 dpi gives (6 inches x 180 dpi) x (4 inches x 180 dpi) = 1080 x
720 pixels – which more or less totally fills a 1024x768 monitor screen.
An Introduction to Scanning 10 AHS Computing
Resolution
Guideline for resolution?
75 – 150 dpi for the web
200 – 600 dpi for printing
600 dpi + for digital photography
An Introduction to Scanning 11 AHS Computing
Comparison???
Can you tell the difference? Is there a difference???
An Introduction to Scanning 12 AHS Computing
Resizing
Because bitmaps are resolution dependent, it's difficult to increase or decrease their size without sacrificing a degree of image quality. When you reduce the size of a bitmap image through your software's resample or resize command, you must throw away pixels.
When you increase the size of a bitmap image through your software's resample or resize command, the software has to create new pixels. When creating pixels, the software must estimate the color values of the new pixels based on the surrounding pixels. This process is called interpolation.
An Introduction to Scanning 13 AHS Computing
Resizing
When resizing a picture make sure to keep the aspect ratio
For instance if you were to only reduce the height of a picture, then everything would appear ‘squished’
An Introduction to Scanning 14 AHS Computing
Manipulating a Photo
Scanning software will allow the user to rotate, crop, lighten/darken a photograph
If a photograph is damaged, it can be restored to its original condition
This step can be completed prior to saving the file or it can be done in post production
An Introduction to Scanning 15 AHS Computing
Post-Production
Select View & Print in the HP’s Director software
Demonstration
An Introduction to Scanning 16 AHS Computing
Post Production
An Introduction to Scanning 17 AHS Computing
Scanning a document
Depending on the scanner and the software the choice to scan to:
– Wordpad (OCR)
– Image
An Introduction to Scanning 18 AHS Computing
OCR
Often abbreviated OCR, optical character recognition refers to the branch of computer science that involves reading text from paper and translating the images into a form that the computer can manipulate (for example, into ASCII codes).
An OCR system enables you to take a book or a magazine article, feed it directly into an electronic computer file, and then edit the file using a word processor.
http://www.webopedia.com/TERM/o/optical_character_recognition.html
An Introduction to Scanning 19 AHS Computing
Pitfalls of OCR
You will still have to edit the document for characters that were not recognized
– This could be tedious and time consuming
Formatting will still need to be need to done
An Introduction to Scanning 20 AHS Computing
Use My Pictures
My Pictures is located in My Documents
This is an excellent place to store pictures
– By default most applications will try to store picture file types to this directory
Use thumbnails to obtain a preview of the files without having to open the file
Protect your scanner
Try to avoid moving your scanner
Do not touch the scanning surface
To clean the surface, use a mixture of
– ½ water
– ½ alcohol
An Introduction to Scanning 21 AHS Computing
Other tips
Be patient… if a scan does not appear right away do not become click happy
If at first you don’t succeed…
Give your scans names that are applicable/relevant and organize them in folders
Save a copy of the scan before you edit the original
An Introduction to Scanning 22 AHS Computing
An Introduction to Scanning 23 AHS Computing
Question & Suggestions…
If you have questions or suggestion, please contact me at your leisure
Lowell Williamson