Digitization Standards and Guidelines

Digital Initiatives uses federal and UC-wide standards and best practices whenever possible in order to make our collections consistent with digital collections across the country, and to facilitate efficient workflows. We exercise flexibility based on the need of the project.  The type of material, donor requirements, target audience, intended use, and funding availability are all factors in the decisions for individual projects.

Following are the very brief, general digitization specifications for material types in the library's digital collections:

 
  Resolution Color  Bit depth Master file format/extension Details
Textual materials with no images Min: 150
Ideal: 400
Grayscale 8

Min: PDF/A
Ideal: JPEG 2000 or TIFF

Optional Character Resolution (OCR) applications work best on documents scanned at 400 DPI or higher.  Web access files: PDF/A.

Textual materials with illustrations Min: 400
Ideal: 600
Min: Grayscale
Ideal: Color
Min: 8
Ideal:  16
TIFF Optional Character Resolution (OCR) applications work best on documents scanned at 400 DPI or higher.  Web access files: PDF/A.

Rare books and manuscripts Min: 300
Ideal: 600
RGB  Min: 8
Ideal:  16
TIFF  

35mm slides, film and negatives smaller than 4"x5" Min: 2000
Ideal: 4000
Min: Grayscale
Ideal: Color
Min: 8
Ideal:  16
TIFF We aim for images to have 4000 pixels across long dimension of image area, excluding mounts and borders

Photographs (prints)

Min: 300
Ideal: 600

Min: Grayscale
Ideal: Color

Min: 8
Ideal: 16

TIFF We aim for images to have 6000 pixels across long dimension of image area

Posters, prints, and maps larger than 8”x10”

Min: 400
Ideal: 600

Min: Grayscale
Ideal: Color
Min: 8
Ideal: 16
TIFF We aim for images to have 6000 - 12,000 pixels across long dimension of image area

Audio 96 kHz   24 Broadcast .wav or .aif

Web access files: 320 Kbps sampling rate. File format: mp3


Video (transferred from VHS or other analog source) 720x486   8-10 uncompressed .mov or .avi Web access files: 1.5 Mbps sampling rate. File format: mp4 h.264

Digital video Native   Native, or 10 bit uncompressed Native, or .mov or .avi Web access files: 1.5 Mbps sampling rate. File format: mp4 h.264

For more information about DPI and PPI, see scanning sizes explained.

Sources:

Association of Recorded Sound Collections (ARSC) Guide to Audio Preservation. May 2015. http://www.clir.org/pubs/reports/pub164/pub164.pdf

Federal Agencies Digitization Guidelines Initiative (FADGI) Still Image Working Group. Technical Guidelines for Digitizing Cultural Heritage Materials. Draft September,  2015. http://www.digitizationguidelines.gov/still-image/

 

File Naming Conventions

  • Use underscores or dashes instead of spaces
  • Avoid special characters such as: " / \ : * ? < > [ ] & $ .
  • Use leading zeros in numbers to facilitate sorting:  Use 008, instead of 8.

File Management 

  • Organize files logically
  • Decide on a naming convention before data collection starts and be consistent
  • Use descriptive file names​