FADGI Image Performance Report
The FADGI Guidelines (Federal Agencies Digitization Guidelines Initiative) define numerical ranges for the performance of digital capture equipment used in federal institutions such as the Library of Congress. Because of its extensively-researched criterion and emphasis on practical but comprehensive and objective image analysis, these guidelines are also used in many non-government settings. The guidelines define four tiers of quality: 1-star, 2-star, 3-star, and 4-star. To attain a certain tier of quality the digital capture equipment must demonstrably and consistently exceed a variety of quality metrics. Simply put, FADGI is similar to national crash-safety testing or mile-per-gallon testing of cars; they provide an objective evaluation rather than relying on a manufacturer’s subjective marketing statements. Two other similar initiatives are the Metamorfoze guidelines in Europe and the ISO 19264 standard that comes from the ISO (DT is a member of the ISO in order to help evolve and promote that standard). We discuss image quality guidelines, and why you can’t just trust your eye to evaluate image quality, in our Digitization 101 course.
At DT Cultural Heritage, and our service wing Pixel Acuity, we focus on producing solutions and services that meet or exceed all criteria for four-star FADGI assessment (or the top tier of quality from Metamorfoze or ISO 19264). This requires exceptionally high sampling efficiency (a.k.a. sharpness), very low chroma errors (a.k.a. color accuracy), high light uniformity (a.k.a. very even lighting) and nearly zero color misregistration. Many companies and service providers claim to reach “FADGI-4 quality” – as we do below with a sample report from the Phase One iXH and 72mm Mk II lens. But we don’t think you should take our word for it (nor anyone else’s); instead, we encourage our clients to independently verify the quality of our equipment (and the equipment and services of other vendors) themselves. We are a Golden Thread and ISA Target dealer and are glad to loan targets and provide access to evaluation software to run those targets through – just contact us. We even teach a Digitization 201 course that includes a detailed section on how to interpret the charts and numerical reports from Golden Thread.
We want our clients to demand the best image quality, and we want to meet that demand because digitization done poorly is eventually redone at the cost of additional money, handling, and time. It’s better to do it right the first time.