Home >> Policy >> Digitization Guidelines

Scanning Specifications

Any materials digitized for the NIUDL must adhere to the following minimum requirements. Any divergences from these minimum requirements will be documented in the project's specifications.

Text (Books, Newspapers, Documents)

Image Types Bit Depth Color Space Resolution (ppi) Scale File Format
B&W Text Only 1-bit Bitonal 600dpi 100% (1:1) TIFF (uncompressed or lossless compression)
B&W Text with Illustrations 8-bit Grayscale 400dpi 100% (1:1) TIFF (uncompressed)
Text with Continuous-Tone Images & Photos (Color) 24-bit RGB 400dpi 100% (1:1) TIFF (uncompressed)

Photographs (Prints)

Image Types Bit Depth Color Space Resolution (ppi) Scale File Format
B&W Photographs 8-bit Grayscale 600dpi 100% (1:1) TIFF (uncompressed)
Color Photographs 24-bit RGB 600dpi 100% (1:1) TIFF (uncompressed)

Photographs (Negatives and Slides)

Image Types Bit Depth Color Space Resolution (ppi) Scale File Format
B&W Negatives and Slides 8-bit Grayscale 5,000 pixels across the longest side 100% (1:1) TIFF (uncompressed)
Color Negatives and Slides 24-bit RGB 5,000 pixels across the longest side 100% (1:1) TIFF (uncompressed)

Large Format (Posters and Maps)

Image Types Bit Depth Color Space Resolution (ppi) Scale File Format
B&W Posters and Maps 8-bit Grayscale 5,000 - 10,000 pixels across the longest side 100% (1:1) TIFF (uncompressed)
Color Posters and Maps 24-bit RGB 5,000 - 10,000 pixels across the longest side 100% (1:1) TIFF (uncompressed)

Scanning Practices and Procedures

Handling

  • Materials are handled as little as possible and stored in a secured location when not in use.
  • Bound materials are scanned lying flat.
  • Scanning of tightly-bound materials occasionally requires removing the binding, which is done in consultation with the Project Manager and Content Provider.
  • Glass is used to flatten pages for scanning, but only when it poses no danger to the materials.
  • Uncut book edges will be cut by scanning technicians, unless otherwise requested.
  • Materials are handled with bare hands, unless otherwise requested.

Scanner Calibration

  • Scanners are calibrated each week for color consistency. Targets are used to ensure accurate color capture and focus.
  • Monitors are calibrated each month.
  • Scanners are serviced each year.

Image Manipulation

In accordance with best practices, image manipulation is kept to a minimum after scanning. In the event that significant problems are identified, the batch will be re-scanned. For this reason, consistent quality control is extremely important. Some exceptions to image manipulation include:

  • Images may be desewed or rotated, as needed.
  • Images are always cropped, leaving a small border of space (1/4") around each item.

File Storage

Files are given meaningful names, typically indicating the collection or project that the files belong to. They are stored on the University Libraries' Network Attached Storage (NAS) in the Scanning directory during production, then copied to the Staging directory when they are ready to be published. Files are removed from the Scanning directory after they have been published.

Digital Publishing

Two mechanisms are used for publishing digital content: batch ingest and form ingest. Batch ingest involves creating a Submission Information Package (SIP) for each file in a batch of files. These typically consist of a MODS record and the appropriate directory structure, which varies by content type. This allows NIUDL to publish many assets at the same time, unmediated. Form ingest involves publishing one file at a time through the NIUDL front-end and does not require technical knowledge or server access, allowing those outside of NIUDL staff to participate in publishing, include staff from other Library units and partners at other libraries. Ingest forms are developed by the Metadata Librarian in consultation with the Project Manager.

Contact

For questions and comments about NIUDL scanning specifications, practices, and procedures, or to suggest corrections, contact:

Brian Conant
Digital Scanning Coordinator
(815) 753-1002
bconant@niu.edu

For questions and comments about NIUDL digital publishing, contact:

Matthew Short
Metadata Librarian
(815) 753-9868
mshort@niu.edu