Michael D. McGuire

Building a fine-art reproduction system from standard hardware

Most fine art reproduction workflows to date have been based on hyperspectral devices. These devices capture, process and print more than three channels of spectral data to produce spectrally accurate reproductions. While these workflows have unique advantages over standard three-channel workflows, such as the ability to produce reproductions that are colorimetrically accurate across many illuminants, they usually require custom hardware. Such hardware can be expensive, time-consuming to setup, and may require a full-time trained operator. We describe the challenges and issues in constructing a colorimetrically accurate fine art reproduction work- flow based on standard three-channel hardware. The workflow was designed to be as automated as possible, simple to use, and device-independent. The heart of the workflow is a software application that takes as input camera characterization data, reflectance statistics of the artwork, an image of the artwork, and an image of a reference card, and it outputs a properly exposed, uniformly illuminated and colorimetrically accurate reproduction. We describe the methods used to compute the exposure level, to compensate for illumination non-uniformities, and to generate a per-image color correction matrix. Finally, we present reproduction results and error statistics obtained using a workflow comprising a 4x5” Sinar camera, a Betterlight digital back, and an HP DesignJet 5500 printer.