Digital Reproduction of Small Gamut Objects: A Profiling Procedure based on Custom Color Targets

In this paper the optimization of color accuracy of digital reproductions is approached. Standard color targets currently available on the market, are constituted of colors spread uniformly in the color space, therefore, these targets are usable in any situation, i.e. for any chromatic content of the images to be profiled. The usage of standard color targets becomes an issue when the object that has to be reproduced is characterized by a small gamut of colors [1,2]. In this case the ICC profile that can be obtained with a standard color target may miss to match with sufficient accuracy the dominating color due to two different causes. First, with reference to the colors of the standard target, the software used to create an ICC profile attempts to optimize all colors, including those which are not present in the object. Secondly, the color of the object can be colorimetrically distant from the patches of the target and therefore the interpolation process required results in a low level of precision. Hence the profiling process would work better if the color of the patches of the target were chosen with reference to the palette of the object that has to be reproduced. Here this problem is approached empirically by developing a new profiling procedure. A custom-made color target has been created in order to optimize the color accuracy of the digital reproduction of a small gamut object. Selection of colors has been carried out from a color catalogue, choosing a set with colorimetric values uniformly distributed in the volume of the color space took up by the gamut of the object. Then, the creation of the ICC profile has been carried out referring to the new target. The main results obtained though a comparison between the developed custom profiling procedure and the standard profiling procedure confirmed a higher precision of