Imaging Specifications

In general, the Digital Initiatives Program follows the guidelines specified by FADGI, the U.S. federal guidelines for digitization.  BCR’s CDP Digital Imaging Best Practices is also useful here.  Additionally, refer to the University of Illinois’ Best Practices for Creating Digital Content for more information.

Photograph

Archival:

  • File format: TIFF
  • Bit depth: 48-bit color
  • Spatial dimensions: 3000-4000px on longest dimension
  • Resolution: 400ppi-600ppi

Service master:

  • File format: TIFF
  • Bit depth: 48-bit color
  • Spatial dimensions: 3000px on longest dimension
  • Resolution: 400ppi-600ppi

Derivatives / access copies:

  • File format: JPG
  • Bit depth: 8 bit grayscale / 24 bit color
  • Dimensions:
    • Thumbnail: 100px on longest dimension
    • Small: 300px on longest dimension
    • Medium: 600px on longest dimension
    • Large: 1200-1500px on longest dimension
  • Resolution: 100ppi

Printed Text

N.B.: In general, use your discretion – if a printed text item contains images, color, etc., it is best to treat it as a photograph.  We recommend a consultation with the Digital Initiatives Program before beginning any scanning project to determine the best method of capture.

Archival:

  • File format: TIFF
  • Bit depth: bitonal
  • Spatial dimensions: 3000-4000px on longest dimension
  • Resolution: 300ppi (may need to increase if using OCR software)

Service master:

  • Same as archival

Derivatives / access copies:

  • File format: JPG
  • Bit depth: 8 bit grayscale / 24 bit color
  • Dimensions: 1200-1500px on longest dimension
  • Resolution: 300ppi

In some cases, a JPEG2000 can be used as a derivative. Contact the Digital Initiatives Program for more information.