Eric Hoarau

On-Demand Digital Print Services: A New Commercial Print Paradigm as an IT Service Vertical

On-demand digital print service is a form of personalized manufacturing service. Key to commercial print value-creation chain is the service engagement and fulfillment between the content suppliers and the print service providers (PSP). Content suppliers are the service clients, they request print services and supply content for print. PSPs provide the fulfillment services to the content suppliers in exchange for payment: converting the supplied content into printed products and shipping them to the end-customer. In this paper, we will describe on-demand digital print service, and the application of service-oriented architecture (SOA) as platform to integrate information and communication technologies (ICT) into the end-to-end print service fulfillment process to enable digital print automation, and the SOA implementation assisted by process modeling. We also extend the SOA framework to include the order negotiation process and envisage a coupled demand-fulfillment paradigm. SOA-based digital print automation leverages from the integration of ICT into the print manufacturing operations management, it is an IT service vertical.

Operations simulation of on-demand digital print

On-demand digital print service is a form of personalized manufacturing service. Key to the commercial print value-creation chain is the responsive and accurate knowledge discovery and decision making throughout the service engagement and fulfillment between the content suppliers and the print service providers (PSP). The business model of on-demand print imposes a great challenge to the PSP factory design, production planning and management due to its intrinsic, highly volatile demand stream. It pushes the PSP resource planning and production management from a form of “tribal art” towards data driven management science. Operations simulation and its practice is an integral component of the data-driven decision making process, and is gaining growing significance. In this paper, we describe operations simulation of an end-to-end digital print process; we treat the management of print manufacturing as a heterogeneous, concurrent, integrated system, accounting for the performance, efficiency, stability, and sustainability as organic system attributes. We exhibit the comparison between the simulation results and the factory internal audit information and show good agreement.

A hardcopy backup and reconstruction system for digital images

Large amounts of images are captured every day and digital storage solutions are the most prevalent approach to preserve them. This paper proposes to augment the existing solutions with a modernized hardcopy backup, which can serve as a fall-back solution if everything else fails and can be enjoyed at the same time. In particular, the collection of images is printed in form of an inexpensive photo-album, which is augmented with printed human readable meta-information designed to enable an easy reconstruction of the the digital version of the original images. The methodology is illustrated using a set of digital sRGB images and printed simulations of faded versions of those images, which are scanned and reconstructed in an automatic and manual way and are compared to the results of a scanner reconstruction software and to the original images.

ICC profiles: are we better off without them?

Before ICC profiles, a device-independent document would encode all color in a device independent CIE space like CIELAB. When the document was to be printed, the press person would measure a target and create a color transformation from the CIE coordinates to device coordinates. For office and consumer color printers, the color transformation for a standard paper would be hardwired in the printer driver or the printer firmware. This procedure had two disadvantages: the color transformations required deep expertise to produce and were hard to manage (the latter making them hard to share), and the image data was transformed twice (from input device to colorimetric and then to output device coordinates) introducing discretization errors twice. The first problem was solved with the ICC profile standard, and the last problem was solved by storing the original device dependent coordinates in the document- together with an input ICC profile-so the color management system could first collapse the two profiles and then perform a single color transformation. Unfortunately, there is a wide variety in the quality of ICC profiles. Even worse, the real nightmare is that quite frequently the incorrect ICC profiles are embedded in documents or the color management systems apply the wrong profiles. For consumer and office printers, the solution is to forgo ICC profiles and reduce everything to the single sRGB color space, so only the printer profile is required. However, the sRGB quality is insufficient for print solution providers. How can a modern print workflow solve the ICC profile nightmare?

Assessing color reproduction tolerances in commercial print workflow

Except for linear devices like CRTs, color transformations from colorimetric specifications to device coordinates are mostly obtained by measuring a set of samples, inverting the table, and looking up values in the table (including interpolation), and mapping the gamut from input to output device. The accuracy of a transformation is determined by reproducing a second set of samples and measuring the reproduction errors. Accuracy as the average predicted perceptual error is then used as a metric for quality. Accuracy and precision are important metrics in commercial print because a print service provider can charge a higher price for more accurate color, or can widen his tolerances when customers prefer cheap prints. The disadvantage of determining tolerances through averaging perceptual errors is that the colors in the sample sets are independent and this is not necessarily a good correlate of print quality as determined through psychophysics studies. Indeed, images consist of color palettes and the main quality factor is not color fidelity but color integrity. For example, if the divergence of the field of error vectors is zero, color constancy is likely to take over and humans will perceive the color reproduction as being of good quality, even if the average error is relatively large. However, if the errors are small but in random directions, the perceived image quality is poor because the relation among colors is altered. We propose a standard practice to determine tolerance based on the Farnsworth-Munsell 100-hue test (FM-100) for the second set and to evaluate the color transpositions-a metric for color integrity-instead of the color differences. The quality metric is then the FM-100 score. There are industry standards for the tolerances of color judges, and the same tolerances and classification can be use for print workflows or its components (e.g., presses, proofers, displays). We generalize this practice to arbitrary perceptually uniform scales tailored to specific applications and present an implementation. In essence, we propose to extend the color discrimination test procedures used to evaluate human observers, to mechanical and electronic color reproduction devices.