Using Scanners
Contents

PURPOSE
TYPES OF SCANS
HOW TO SCAN
EDITING AND SPECIAL EFFECTS
MORE INFORMATION

 
PURPOSE

Scanners can convert an image or text on a printed page to digital form.
Once in digital form it can be used like other digital objects - modified, pasted into documents, and printed.

Uses

Composing work - you can incorporate images (pictures) or into your assignments, that you've found in books or other published materials.

Email - if you want to email someone a document you have in print form only, you can scan it, and attach the resulting file to an email message.

Conversion - a document produced by a Macintosh computer can't be opened by an IBM-compatible (Windows) computer. However if you have a printout of a document you can scan it into the second computer.

Rescue - You've accidentally deleted or mislaid the file containing your assignment! Panic stations! But if you've kept a print-out, you can scan this and recover your work.

 
TYPES OF SCANNING

There are two main types of scanning:

• image - such as pictures, drawings, photographs, diagrams;

• text

Images can be saved in different formats (including the common JPEG, GIF and TIFF formats). The images can then be pasted into documents or sent via email as attachments.

Text can be scanned as an image also, or translated into an editable format.
Translation into editable form requires a feature called Optical Character Recognition (OCR), which is standard on most recent scanners. The scanning process creates a Microsoft Word document, or an alternative word processing format.

Handwriting can't as yet be handled by OCR - a handwritten page can only be scanned as an image.

HOW TO SCAN

Scanners are installed in NCI campus libraries and some computer rooms and Learner Support Centres. The make and model will vary.

Three important things before you start:

1. Find out which PC will access the scanner and advance book it if necessary.
The scanners are often networked, and therefore will be available from all the computers in an NCI facility. If in any doubt, ask the librarian or teacher in charge about scanner accessibility. If possible, collect a copy of any instructions available, or check whether they are available at workstations or near the scanner.

2. Leave yourself plenty of time for your scanning session, and make sure you will be able to come back for a second try. Scanning is not a task to be left until just before your assignment is due. Scanners operate slowly, and sometimes results can be unpredictable.

3. Bring a disk
You will need to save your work onto a disk. Write your name and phone no. on the label, and the intended content eg "images for horticulture assignment"

Finding scanner software
Scanner software can be located by clicking the Start button in Windows and looking under All Programs. Usually "Scan" will form part of the name of the scanner program eg DeskScan, PrecisionScan.

BASIC STEPS IN SCANNING

Place your document or picture face down on the scanner glass. Check for arrows etc which indicate which corner of the glass you should use as the edge.

What sort of scan?
The software will ask you about your image - is it a colour photo, B&W line drawing, text etc. to enable it to do the best possible scan.

Where are you saving?
The software will ask to if you are saving to a particular application eg Microsoft Word, and how you would like to name your file. The default is usually to save as an image. At this stage you also choose the file type.

Suggestion: save initially to a directory on the computer. The scanning software usually suggests a location. When you're satisfied with your image, you can save it to your disk.

Previewing
The scanner will do a preliminary scan to the computer screen. It's then possible to select only part of the image to be scanned in the final scan, by using the tools provided. This will minimize after-scan editing, and will keep your file from being unecessarily large.

Resolution
Normally you can choose a resolution (sharpness) for your image. It's expressed in dpi (dots per inch). High resolution (more dots per inch) is nice but can create huge file sizes. Initially, start with the default resolution.

Choice of file type for images

TIFF is a versatile format, suitable for eg pasting into Publisher documents.
GIFs are suitable for Web pages. They tend to be smaller than other image filetypes because of decreased colour depth.
JPEGs are also suitable for on-line images. The images can be compressed to varying degrees to reduce file size. Although a corresponding amount of detail is lost, the image quality is still very usable in most cases. Look in the drop-down menus or the Help function of the scanner software, to find out how to choose the compression ratio of any JPEG files you create.

Finally

Save your file to disk and take it with you, even if you have done a satisfactory final printout of your work. You may need the file again.

EDITING AND SPECIAL EFFECTS

There will be tools within the scanning software to change the colour balance and tonal qualities of the image. You can also alter the image after you have created it by using graphics software - there is usually a graphics package included with scanning software. This will allow you to play with the image further - cut bits out, add special effects etc.

MORE INFORMATION

For detailed technical information about the operation of scanners, try the PC Techguide site.