What is the FADGI Star System?

Federal Agencies Digital Guidelines Initiative (FADGI) is known worldwide as a collaborative effort that was started more than a decade ago by U.S. federal agencies to communicate the common sustainable practices and guidelines for digitizing historical, archival, and cultural content. In other words, this is an objective set of best practices and guidelines that can be used to form a technical foundation for digitization activities.


Within the agencies, there are two distinguished working groups: one for still images and the other for audio-visual materials. The Still Images Working Group’s efforts are developing common digitization guidelines for content such as books, manuscripts, maps, photographic prints, and negatives. This is Image Retrieval’s area of expertise. The Audio-Visual Working Group’s primary focus is development of the technical guidelines, methods, and practices for digitized and born digital sound recordings, moving images, and motion picture film.


FADGI has created a free downloadable document called The Technical Guidelines for Digitizing Cultural Heritage Materials. This is a comprehensive guideline that specifies best digitization practices for materials that can be reproduced as still images.



There are many sections of the Guidelines that are informative on a variety of topics within the digital process. We recommend that anyone involved in digitization read the complete guidelines because of the wealth of knowledge it provides. As the i2s reseller for the United States, Image Retrieval’s main interest in this document is the FADGI Star System used to evaluate how accurately a capture device (scanner) can create a digital image of physical materials such as books, maps, manuscripts, newspapers etc.


The Star System is an unbiased grade you can assign to a scanner based on the accuracy of the images it produces. With so many misleading scanner specifications you see on the market (optical resolution, X and Y interpolation, lp/mm, depth of field, color depth, etc.) it is hard to know how well one scanner performs over another. FADGI takes out the confusion and assigns a star quality rating from one to four stars. Three stars is defined as a very good professional image while a four star image is defined as the best image practical today. One and two stars are typically not known as archival quality. i2s has aimed to make their scanners either 3 or 4 star compliant and they will proudly advertise when those levels are met. The CopiBook OS and QUARTZ A1 HD are their most popular 3 and 4 star scanners in the United States.

To know your scanner’s star level, you will need something known as a GoldenThread/DICE target that can be scanned and analyzed by unbiased software. Don Williams of Image Science Associates (ISA), is a key player in the advancement of FADGI and has developed the GoldenThread™ System, one of the current industry standards on digital evaluation and compliance with the FADGI 1 to 4 star rating. The GoldenThread System includes two very accurate and calibrated targets and the analysis software that measures them. The GoldenThread device level and object level targets are manufactured with exact materials and tolerances so that the software can determine the level of error relative to the aim value of the target and from this the FADGI Star level can be assigned.


The GoldenThread targets are designed with color patches based on the Munsell Color System for the highest levels of accuracy and consistency. Once a target is captured on a scanner, the digital image can be loaded into the GT analysis software. The user will then be able to view a variety of data analysis, in both graphical and numerical presentation, which shows the performance of the scanner and the fidelity of the digital image. This analysis defines the overall performance of the scan in multiple areas and then assigns a FADGI Star rating to the image.


If you are interested in learning more about FADGI or would like to implement GoldenThread into your workflow, please contact Image Retrieval. As a reseller for Image Science Associates and i2s, we are able to provide the scanners, targets, and software needed to create a FADGI-compliant digitization program.

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