University Libraries University at Buffalo
Digital Collections

Digitization Standards

Still Images

Images should ideally be digitized at the same resolution as they were created. Based on the source resolution, here are some common rules of thumb for selecting a scanning resolution:

  • Newspapers: 150 dpi
  • Most books: 200-300 dpi
  • High quality books, art books: 400 dpi
  • Most laser and inkjet printers print at 600 dpi
  • 35mm slides: 4000 dpi
Source Resolution Digital Output Size
Newspapers 150 dpi Half broadsheet: 2212 x 3525
Book 200-300 dpi Octavo: 1800 x 2700 (at 300 dpi)
Art Book 400 dpi Quarto: 3800 x 4800
Mounted Slide 4000 dpi 35mm: 5680 x 3800

Resolutions vary by the printing process, and the make and model of the printer. A good strategy is to try several resolutions, and pick the one that provides the highest quality results. Higher resolution does not automatically mean higher quality.

If possible, select a resolution that will yield image masters with a minimum height or width of 1,000 pixels. This won't always be possible, and sometimes the answer is to look for a better-quality source.

Recommended Master Image File Format:

  • Uncompressed TIFF
  • 24-bit color, 16-bit grayscale or 1-bit bitonal (for text and line art)

When contributing materials to the institutional repository or the digital library, display images (i.e., the image files accessed by the community) are automatically created when the master images are uploaded. When manually creating a website, these display images might need to be created by hand as well. Ideally, by direct access or by clicking through smaller thumbnail images, the users should be able to view display images of at least 1,000 pixels on one side. Display files should be formatted as JPEG, and thumbnail files JPEG or PNG.


Multimedia Preservation Files

Standard Definition Video
  • Uncompressed, Full Frame Video (MOV file format)
  • NTSC: 29.97 frames per second
  • 640 x 480 resolution

High Definition Video
  • Uncompressed, Full Frame Video (MOV file format)
  • Preserve same frame rate
  • 1280 x 768 resolution

Audio Files
  • Sampling rate 256kHz, 24-bit
  • Standard WAV file format
  • Uncompressed

Multimedia Presentation Files

Standard Definition Video
  • Compressed MP4 file format
  • 640 x 480 resolution

High Definition Video
  • Compressed MP4 file format
  • 1280 x 768 resolution
Audio Files
  • Sampling rate 256kHz, 24-bit
  • MP3 file format

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