Creating High Quality Scans
Sometimes it is necessary to scan a document for an instructional need. When documents are in electronic form, they are easier to distribute and can be more accessible than print documents for students with disabilities. However, in order to be fully accessible, certain steps must be followed to be sure the scanned document is of high quality. Even if a document is not needed for a person with disability, a poor scan often negatively impacts the end user’s experience.
Evaluate Need
Before scanning a document, first evaluate if this particular document is needed and cannot be substituted. If it is necessary, search for the document online to see if an electronic version already exists. This can save time and energy.
What is A High Quality Scan?
A high quality scan is one that is easy for everyone to read, including individuals with low vision or who use assistive technologies to read text electronically. High quality scans should be free from:
- Text that is cut off
- Crooked pages
- Dark gutters (the margins where shadows occur from curvature in the book’s spine)
- Poor contrast
- Pages that are rotated 90 or 180 degrees
- Handwriting
- Highlighting
- Underlining
- Watermarks/coffee stains
- Poor contrast
- Excessive use of script or italic fonts
- Blurry
Be sure to consider these issues when (a) choosing an original source and (b) producing the scanned version.
See these examples from the University of Washington.
Example A. Scanned page with unreadable text in the margin
Example B. Scanned page with underlined text and stray markings
Example C. Page scanned with original not aligned well on scanner; page is tilted, text is blurry, and some text disappears into the margin
Example D. A scanned page with good alignment, clear text, and no stray markings.
Before Scanning, Change Settings
When changing the scanning settings, please
- Check the DPI (dots per inch) are set between 300 and 400. Documents scanned at a low resolution will not be recognized by conversion software. Scanning documents at 600 dpi might be necessary for certain STEM content or other highly formatted documents.
- Scan the document in black/white or 24-bit color depending on (a) whether the color of the original is important, and (b) whether your choice of color will have an effect on contrast.
- Check if the scanner has built-in Optical Character Recognition (OCR) capabilities. OCR turns images of text into text that is copy and pasteable. Often, this option is identified as saving a document as a Searchable PDF.
- Consider removing the binding of the book if the gutter is small or tightly bound. This allows for high speed scanning. The book can then be re-bound with spiral binding for low cost at a local copy shop.
While Scanning
During the scanning process, please be aware of the following:
- Scanning books with a spine – A book with a spine will not naturally lie flat on a scanner which means text on the edges of the page will be distorted. Please push the spine of the book down while scanning to ensure that all the text is copied in a clear manner.
- Don’t combine pages – Limit each print page to one electronic page will improve reading on mobile platforms. This also helps to speed up the conversion process using OCR software.
Name Documents Consistently
A consistent, logical naming scheme will help instructors and users to identify and locate documents. Choose a naming scheme that would be clear to someone outside of the class/environment. Please:
- Avoid strings of numbers
- Include more than one identifier in the title. An identifier can include the course name, author, name of document, date, organization, year published, etc.