Digitization Philosophy
The Digital Heritage Center digitizes materials for the purpose of facilitating online viewing and research. Our intention is not to create a high fidelity replica suitable for replacing the original, but rather to allow users to view and search a quality representation of the item. We also provide optical character recognition where possible, to increase access through full-text search.
Scanning Specifications
These scanning specifications accommodate our digitization philosophy while also adhering to accepted imaging best practices, particularly those developed by the Federal Agencies Digitization Guidelines Initiative.
| Item Type | PPI | Hardware | Example Item |
|---|---|---|---|
| Photographs | 600 | Epson Expression 10000XL | Classmates in Albemarle |
| Negatives or Slides | 1200-1600 | Epson Expression 10000XL | Horse-Drawn Carriage in Parade |
| Fragile Looseleaf or Bound Items | 400 | Zeutschel | Copy of Robert E. Lee’s Farewell Address |
| Very Fragile and/or Oversized Items | 300 minimum | PhaseOne | The Full Moon |
| Uniform and Sturdy Looseleaf | 300 | Fujitsu Sheetfed Scanner | Hickory Library Business Vertical Files |
| Bound and Sturdy Publications | 300-450 | Internet Archive Scribe Book Scanner | Lamp and Shield |
| 3-D Objects | 300 minimum | Nikon Digital Camera | Child’s Doll |
We contract to digitize microfilm off site. Contact us for more details about this process.
To learn about the kind of file formats we create and retain, review File Formats Used by the Digital Heritage Center.
Digitization Overview
- Receive and unpackage materials
- Assess for condition issues, presence of metadata
- Separate out materials by format and/or subject matter
- Decide which hardware to use for digitization
- Calibrate hardware
- Digitize materials
- Review images and apply image rotation if necessary
- Run images through OCR (optical character recognition) software if appropriate
- Create image metadata in spreadsheet
- Upload images and metadata to our content management system
- Publish to digitalnc.org
- Ask partners to quality control our work
- Re-package and return materials
Description of Scanning Practices
Digital Heritage Center materials are digitized in the Digital Production Center (DPC) in Wilson Library, University of North Carolina at Chapel Hill. Here are photos and details about many of the scanners and cameras used.
Staff use the following best practices when scanning materials:
Handling
- Items are handled as little as possible and are stored in secure locations when not in use.
- Bound materials are opened gently and scanned lying flat. Props and book cradles are used when necessary.
- Glass is used to flatten pages only when it poses no danger to the materials and does not inhibit image quality.
- Unless requested by the owning institution, paper materials are handled with bare hands to facilitate dexterity. Photographs, slides, negatives, and museum objects are handled with cotton gloves.
- To avoid shadows in the gutter for bound items being shot with digital cameras, the volumes may be turned perpendicular to the light source.
Hardware Calibration
- Monitors are calibrated for color consistency.
- When using digital cameras, the hardware is calibrated based on the size and type of object. This calibration is specific to the type of hardware.
- Targets are used to ensure color fidelity and accurate focus for each item captured.
What We Usually Skip
- Blank pages
- The backs of documents and photos if there is no unique or helpful content
- Spines of bound objects
About Scrapbooks
- We unfold and scan unique multi-page items that are inside of scrapbooks (like small pamphlets or booklets)
- When scanning multi-page items inside of a scrapbook, we scan the entire scrapbook page each time to maintain context.
- Items in enclosures are carefully removed for scanning if no damage will result.
- We do not lift or remove the plastic page protectors that adhere to scrapbook pages.
- Scrapbooks bound by posts are sometimes disassembled, if doing so provides a better scan and/or gentler handling, and if no damage will result.
Color
We scan in color, using the sRGB colorspace.
Image Manipulation
Following digitization best practices, we do minimal manual image manipulation.
- No “touchups,” intensive color correction, dust or scratch cleanup
- Images may be deskewed or rotated
- Images are cropped to leave a small, uniform border of space around each item.
Project and Workflow Management
Multiple staff members are involved in digitization and digital publishing at the Digital Heritage Center. We have found Trello to be a great tool for managing workflows.
Spreadsheets and documentation on Google Drive allow us to share information and to track project progress.