Three-dimensional printing is a powder-based solid freeform fabrication technique. It is based on conventional ink jet printing technology, basic materials being powders and binders (inks). As the process uses colored binders, text and graphic elements can be reproduced on the objects. The reproduction of three-dimensional prints surface elements was evaluated, also using image analysis, which was studied as a tool for reproduction evaluation. A test target, consisting of selected geometric and text elements, was placed on the surface of designed three-dimensional plate. The test plates were placed in different relative xyz positions, as well as printed with different preferences. The evaluation was done on light microscope captures, while scanned images of three-dimensional prints surfaces were used and observed as well. Changes in three-dimensional printed surface elements reproduction due to the objects' positioning and printing preferences, and binder-powder interactions were discussed. Specific image analysis procedures were researched as a tool for objective reproduction evaluation.

Digital transformation of commercial print production brings new opportunities including exploitation of embedded sensing and computing power that enable real-time communication during various phases of the production chain and dynamic reconfiguration of production flow. Simulation based modeling can help to exploit these opportunities at both strategic and operational levels. In this article we report our ongoing work on simulating an end-to-end print production process. We draw a close parallel between print production design and electronic design automation, and model print production system as a network of interconnected, distinct processes. We describe our simulation framework, simulation validation against queuing network theory, preliminary simulation results, and path to policy design and analysis.

The present study deals with the optical and color stability of aged specialty papers and ultraviolet cured (UV) ink jet prints. As paper substrates, a fiber synthetic paper and two types of lignin-free papers with included security elements were used. Prints of CMYK color fields using UV Curable Inks were made using a UV ink jet printer, Océ Arizona 250® GT. Samples of papers and UV ink jet prints were artificially aged using standard techniques of accelerated aging, such as moist heat (80°C and 65% RH), dry heat (105°C) and treatment with the a xenon arc lamp (35°C CT, 50°C BST, 35% RH). Aging was performed for periods of 1, 2, 3, 6, and 12 days. In this study, optical properties of untreated and treated paper substrates such as the whiteness and yellowness index and color differences between untreated and treated UV ink jet prints were followed. The tested paper substrates behaved differently. The fiber synthetic paper was more stable than both lignin-free cellulose papers. Some color differences during accelerated aging were observed in prints. The effect depends on the particular ink and type of accelerated aging. On average, dry heat treatment and treatment with the xenon arc lamp showed greater impact on CMYK prints than moist heat treatment. The most stable among the prints was the black ink.

The purpose of this study is to examine the influence of light on the changes in typographic and colorimetric properties of ink jet prints in order to establish an appropriate typeface style and type size for business correspondence to ensure information permanence. The prints were made with six ink jet printers from different manufacturers on four different office papers. Four different, widely used typefaces (one old-style, one transitional, and two sans-serif) in five different sizes (6, 8, 10, 12, and 16 pt) were tested. The resistance of printed business correspondence to light was evaluated according to the ISO 12040 standard. The color differences were determined spectrophotometrically. The differences in typographic tonal density and wicking of typefaces were measured with image analysis. After the exposure to light, the biggest difference in typographic tonal density was observed at type sizes 6 and 8 pt, and at one of the sans-serif typefaces.

Image-based applications such as inspection, quality assurance, print quality assessment, and authentication are often bandwidth limited, and benefit from image down-sampling or compression. Often the down-sampling or compression strategy is selected without considering the impact on the functional goal of the imaging task. In this paper, we use a specific "functional" imaging application–the distinction between images of authentic products and counterfeit products–to assess the impact of down-sampling and compression on the classification accuracy of the counterfeit detection imaging software. Our samples are originally scanned at high resolution (600 dots/in, or dpi) and then down-sampled to as little as 10 ppi (continuous tone pixels/in). JPEG compression to 2% and 1% of the original image size were performed separately or in combination with the various down-sampling factors. A simple Gaussian classifier was used throughout. We found that improved classification accuracy was obtained even for samples compressed or down-sampled by more than 99%. The implications of these findings for improved inspection results, authentication accuracy and counterfeit detection are then discussed.

Error-Correcting Code (ECC) provides robust readability to both linear and two-dimensional (2D) barcodes, particularly for localized damage. Many ECC approaches, however, are based on assumptions about the types of damage or the communication channel used. As the applications for barcodes rapidly evolve with the increasing ubiquity of mobile cameras, an evaluation of the trade off between ECC and simply increasing the size of the bar code modules is required. This article compares the impact of simply changing the module size versus using error correction–which exhausts a percentage of the symbol area without adding payload data. For three typical nondestructive types of damage–the print-scan cycle, low quality printing, and blurring–investigated here, there is compelling support for increasing the size of the barcode modules and foregoing ECC. Freeing barcodes from the need for ECC provides an additional advantage: namely, the barcodes can be scrambled to be unreadable under the defined barcode specification without a change in size or appearance. This is in contrast to the use of ECC, for which only a small minority of rearrangements of the data in the barcode would be "decodable." Thus, without the use of ECC, it is much harder for a would-be counterfeiter or other dishonest party to determine the scrambling approach. Additionally, we can create 2D barcodes that are not "readable" using commercially available reading software, except where so desired. These results are discussed in light of destructive damage and for different applications of 2D bar codes.

The effect of laser printer fusing parameters on print gloss was studied. Gloss level directly impacts color range and perceived depth of color and the perceived image quality by the customer. Analysis of gloss dependence upon fusing parameters would guide printer development. Two color printers that differed in fuser design, toner formulation, and gloss performance were tested. The fuser design and control condition and toner type effects on gloss were isolated by using an independent fusing system that allowed samples created in the two printers to be fused using a common process. It was found that image density had the primary effect on gloss and can be classified as low density (substrate dependent gloss), medium density (pattern dependent gloss), and high density (fusing process dependent gloss). Nip duration, pressure, and temperature had only a secondary effect on gloss and may be used to optimize the fusing system process once the fuser design and toner formulation are complete.

The existence of charged particles in corona devices is important in electrophotography. Envelope regions where introduced smoke particles cannot penetrate appear around wires on corona discharge in spite of the polarization of the wires. These particles that are initially positive charged keep away from around the wire and collide with the grid electrode on negative corona discharge. With knowledge of particle charging the author shows the motion of charged particles around a corona wire. Numerical calculations correlate well with experimental results. The author defines the generation process of these regions by comparing the initial flow field with numerical simulation results. In addition, the charge quantity of the smoke particles is estimated.