Our Digital Process

TIFF SPECIFICATIONS

Our standard process provides you with a high-quality TIFF file as your master digital image. From this TIFF image, we can produce a variety of derivatives, perform OCR, and even build your CONTENTdm collection. Defining the TIFF specifications is a key starting point to any project.

1-bit Bitonal Scanning

Bitonal images are composed of a single bit of information per pixel, making each pixel either black or white. Printed textual materials and simple line art are examples of material best suited to bitonal processing.

These bitonal scans produce smaller files that load and print quickly and can be compressed without any loss of information. However, compromised or damaged materials cannot be fully captured, and tonality is lost in faded text, illustrations, and handwritten documents.

8-bit Grayscale Scanning

Grayscale scanning retains the tonal value present in the original, including continuous-tone and halftone photographs and illustrations. These grayscale images are composed of eight bits of information per pixel, providing 256 shades of gray.

Grayscale is optimal for manuscripts, stained material, and documents with heavy bleed-through. Often, grayscale is the only way to effectively capture illustrations and faded text.

Because it captures a wider variety of tonal values than bitonal scanning, grayscale imaging retains more information from the original document. However, since each pixel contains more information, uncompressed grayscale files are substantially larger than those for bitonal images.

24-bit Color Scanning

Color scanning captures Truecolor color values for each pixel of an image, encoded at 24 bits per pixel.

Truecolor is a method of representing and storing graphical image information that allows a very large number of colors, shades, and hues to be displayed in a full-color image. Truecolor defines red, green, and blue values for each pixel of the digital picture, using eight bits — 256 shades — for each of the three component colors. This combination results in approximately 16.7 million available color variations for each pixel.

This type of scanning is best suited to photographs, graphics, and similar content, where nuances of color are critical to replicating the effect of the original image.

16-bit Scanning

Although requested less often, we can also accommodate 16-bit grayscale scanning and 16-bit-per-channel color scanning, if your project requires the extra bit depth.

Scan Resolution

Scanning resolution will vary depending on what type of material you're digitizing. The size of the original material has a direct impact on the recommendations for resolution. For a comprehensive guide, take a look at the National Archives'Technical Guidelines for Digitizing Archival Materials for Electronic Access: Creation of Production Master Files — Raster Images.

Image Processing and Enhancement

Image processing for bound materials that are opened to two facing pages (2-up), can be split into separate image files either during scanning or as a post-scan process. We also offer image processing options that include deskewing and auto cropping or custom cropping for consistent results. Image enhancements, such as adjustments to contrast, brightness, color, and sharpening are also available.

File-Naming and Directories

Backstage organizes your files into directories and names the files according to your needs. Directory structure and file names often reflect the bibliographic or logical structure of the material, such as issue numbers for serials or bibliographic IDs for monographs.

Each file is named according to a scheme based on either simple sequential numbering or file content, such as page numbers or special feature codes denoting illustrations, indexes, etc.

Tagging

TIFF is an acronym for Tagged Image File Format. By tagging, we can include additional descriptive information in your TIFF files. Standard tags in a TIFF file denote width and length in pixels, resolution, and compression. We routinely add non-standard tags as well, such as the image name, source, and creation date. Custom tags can also be added per your specifications.

We comply with the Federal Agency Guidelines for TIFF metadata recommended elements.

Once the high quality master TIFF file is ready, we can help you with these additional processes:

Derivative Files

  • JPEG
  • PDF, searchable and bound per item
  • PDF/A
  • JPEG 2000
  • Text files
  • METS/ALTO
  • Thumbnails, sized to your specifications

Text Conversion

  • Manual transcription to 99+ percent accuracy
  • Mark-up for XML or TEI

Article Segmentation

  • Optional headline correction
  • Optional article jumps
  • Optional by-line tagging
  • METS/ALTO output or imported into CONTENTdm

CONTENTdm Processing

  • Collection building: compound or simple objects
  • Image metadata: both technical and administrative
  • Collection metadata: unique metadata you provide about your collection

Questions? Call us at 1-800-288-1265 or drop us a note.