Not Through a Glass, Darkly

Tips and Tricks forOptimal Scanner Settings

Mary Van Court

University of WashingtonHealth Sciences Library

Before you start…What do you want to scan?

What kind of digital file do you want?

Do you have the right software?

Do you want to scan a photo or a multipage document?

Photos are usually scanned asJPEG or GIF files

Use JPEG for complex images > 16 million colors Not as sharp as GIF

Use GIF for line art or logos

Sharper than JPEG 256 colors

Multipage documents are usually scanned as PDF or TIFF filesMost people are more comfortable with PDF

Some applications require TIFF (such as Ariel for Interlibrary Loan)

Lots of programs to convert between theme.g. DocMorph from the National Library of Medicine (http://docmorph.nlm.nih.gov/docmorph/).

Look at the software

The software that came with your scanner will usually do a good job of scanning photos, but will it do what you want?

Every scanner/software combination is different

Some walk you through the process step by step

Some show all your scanningoptions on one screen

Some give you a few optionsand make you look for the rest

Sometimes there are multiple places to look

Select the file format

dpi = dots per inch

Select the resolutionFor web display100 dpi

For standard printing240 – 300 dpi

For glossy printing or postersScanner maximum

Sometimes the resolution setting is explicit

Sometimes there are sliders

This one shows the relationship between resolution and file size.

Select the image type/mode

Sometimes it’s more cryptic 24-bit color 256 colors 8 colors RGB colors Line

drawing Half tone Text +

photo Generation

Set the physical parameters

It’s often automatic, but sometimes you have to set:

Paper size

Flatbed scanner vs. document feeder

One or two-sided original

Scanner accessories

Adjust the image parameters

Brightness

Threshold

Contrast

Dithering

Despeckle

Sometimes settings are pictures – not words

Does the scan get lighter or darker when you increase the brightness?

Settings are not consistent from scanner

to scanner

Optical Character Recognition (OCR)

ALots of programs to convert paper image to text

Need to scan at 300 – 400 dpi

97-99% accurate

Can create searchable image

Post scanning editingVariety of software

Lots of different features

Shop around for what you want

The bottom line is …There are a

lot of choices. Keep looking until you find

one that works for you.