Standards

Scanning Standards by Type of Material

Digital image collections incorporated into the UNT Libraries’ permanent collections must adhere to the minimum requirements given below. Depending on the specific objectives of the projects, higher resolutions may be desirable for some materials. Please note that this document is not intended to address all technical issues and does not describe the details of operational procedures. See project-specific guidelines for further information.

Text (Books)

Image Types Bit Depth Color Space Resolution (ppi) Scale File Format
B&W Text Only 1-bit Bitonal 600ppi 100% (1:1) Tiff (uncompressed or lossless compression, no LZW)
B&W Text with Illustrations (Photos, Drawings, Plates, Charts) 8-bit Grayscale 400ppi 100% (1:1) Tiff (uncompressed)
Text w/ Continuous-Tone Images & Photos (Color) 24-bit RGB 400ppi 100% (1:1) Tiff (uncompressed)

Documents (Handwritten, Ledgers, Receipts)

Image Types Bit Depth Color Space Resolution (ppi) Scale File Format
B&W Text Only* 1-bit Bitonal 600ppi 100% (1:1) Tiff (uncompressed or lossless compression no LZW)
Handwritten Documents, Ledgers 8-bit Grayscale 400ppi 100% (1:1) Tiff (uncompressed)
Correspondence, Letters 24-bit RGB 400ppi 100% (1:1) Tiff (uncompressed)

* We recommend scanning handwritten documents in grayscale or color.

Photographs (Prints)

Image Types Bit Depth Color Space Resolution (ppi) Scale File Format
B&W Photographs 8-bit Grayscale 600ppi 100% (1:1) Tiff (uncompressed)
Color Photographs 24-bit RGB 600ppi 100% (1:1) Tiff (uncompressed)
  • As of April, 2009, we scan both sides of a photograph even if one side is blank.

Photographs (Negatives and Slides)

Image Types Bit Depth Color Space Resolution (ppi) Scale File Format
B&W Negatives & Slides 8-bit Grayscale 5000 pixels across the longest side* 100% (1:1) Tiff (uncompressed)
Color Negatives & Slides 24-bit RGB 5000 pixels across the longest side* 100% (1:1) Tiff (uncompressed)
  • Not sure how to figure 5000 pixels across the longest side? Download a film sizes guide.
  • For copy negatives, scan the entire negative. Do not crop to the original image. Do not crop out written notes.

Large Format (Posters and Maps) Above 17 x 24 inches (A2)

Image Types Bit Depth Color Space Resolution (ppi) Scale File Format
B&W Maps/Posters 8-bit Grayscale 5000 - 10000 pixels across the longest side 100% (1:1) Tiff (uncompressed)
Color Maps/Posters 24-bit RGB 5000 - 10000 pixels across the longest side 100% (1:1) Tiff (uncompressed)

Newspapers

Newspapers should be scanned and digitally preserved in accordance with the national standards set by the Library of Congress for the National Digital Newspaper Program.

Image Types Bit Depth Color Space Resolution (dpi) Scale File Format
Microfilm 8-bit Grayscale 400* 100% (1:1) Tiff 6.0 (uncompressed)
Physical Pages 24-bit RGB 400 100% (1:1) Tiff 6.0 (uncompressed)
  • Monitor equipment performance by capturing a standards-based target film strip or color image at the start of each scanning session.
  • Split dual images into individual newspaper images as necessary.
  • Deskew images with more than 3% skew.
  • Crop page image files to the edge of the newspaper, retaining the original edge and up to a quarter inch beyond.
  • Produce images that have exactly the same dimensions, spatial resolution, skew, and cropping as the images used for OCR.

*For microfilm, scan at 8-bit grayscale with a resolution of 400 dpi, if possible; otherwise between 300 and 400 dpi (relative to the size of the original newspaper).

Moving Image (Film and Video)

Original Format File Format Codec Audio Resolution
16 mm film QuickTime (.mov) Uncompressed YUV 10-bit 4:2:2​ 48 kHZ, 16-bit Standard Definition (720x480)
VHS, SVHS, Betamax, Betacam, Umatic, DVCAM, DVC Pro, Mini DV, Laser Disc QuickTime (.mov) DV50​ 48 kHZ, 16-bit Standard Definition (720x480)

Audio

Original Format Bit Depth Resolution File Format
Cassette 16-bit 44.1 kHz

Waveform Audio File Format (WAVE)

.wav

Reel-to-Reel, Analog Disk 24-bit 48 kHz to 96 kHz

Waveform Audio File Format (WAVE)

.wav

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