Output devices in print production can be characterized by different characterization methods. One commonly used method of color device characterization is least squares fitting. In essence, the least squares fitting is used to determine the coefficients of a predetermined polynomial, such that the sum of squared differences between the values predicted by the model and the empirical data is minimal. The choice of the polynomial order and the cross product terms which best describe the behavior of a certain device is not obvious. This paper is a part of a larger study which investigates the criteria in the measurement data which can be used for optimal model selection. The part of the study covered in this paper addresses the data over fitting problem. It is investigated by comparing the performance of models of different polynomial orders on two different domains.

Starting point of this paper is photopolymer printing plate used for flexographic printing. It is used for transfer of the printing ink onto the printing surface during the reproduction process. Photopolymer printing plate consists of several layers: polyester basis, photo sensitive polymer material and LAMS - Laser Ablation Mask. In the platemaking process the photosensitive material, which will form a printing plate, has to be several time exposed to different radiation in order to obtain a functional printability performance. LAMS layer has a role of masking in the exposure process. Upon pre-exposure, LAMS layer has to be removed by laser ablation only at the surfaces where photopolymer printing plate needs to be exposed. After ablation the exposures to UV lights follows and the plate will be finished with chemical removal of the unexposed parts of the polymer. Functionality of the finished printing plate has to be characterised and monitored in every procedure step because the formed image element on the printing plate has a major influence on the quality of the finished printed product. In this paper observing of the changes in the polymer material which is caused by exposure through LAMS layer will be performed. The aim is to measure the surface openings on the LAMS mask and to measure surface coverage (image elements) on the polymer material formed by exposure through the LAMS. Measuring will be made by image analysis software based on microscopic images of the control fields of differing halftone values. It is assumed that there will be a correlation between the LAMS openings and formed image elements on the printing plates. Preliminary results indicate that certain differences in image elements can be detected and are probably the consequence of the different amount of irradiated surface of the polymer material. Since the polymer material which forms the printing plate should be stable in the graphic reproduction process, results of the paper will explain the influence of UV exposures on polymerisation process and on the functional printability performance of the plates.

Original scientific paper A new approach to the FMEA (Failure Mode and Effects Analysis -analysis of potential failures and their effects) method implementation in the newspaper production system shows non-compliances that may occur in the selected processes by implementing differentiated quality management system. Each sub-process and work activity within the selected processes in the newspaper production is differentially evaluated, and analysis provides the necessary information about the intensity of occurrence, severity and possible corrective actions in order to achieve and maintain high levels of quality newspaper products. FMEA analysis is presented in the modified tables for the newspaper product production process, and the preventive and corrective actions were recommended based on the results obtained. By performing preventive and corrective actions the occurrence of non-compliance is eliminated or minimized which ultimately makes the process more competitive and removes the non-compliance from the product. Keywords: differentiation of quality management systems; FMEA; newspaper production; non-compliance Implementacija diferenciranog sustava upravljanja kvalitetom i FMEA metode u novinsku proizvodnjuIzvorni znanstveni rad Novim pristupom u implementaciji FMEA metode u sustavu novinske proizvodnje predstavljene su nesukladnosti koje se mogu pojaviti u odabranim procesima, temeljem primjene diferenciranog sustava upravljanja kvalitetom. Svaki potproces i radna aktivnost u okviru odabranih procesa novinske proizvodnje diferencirano se evaluira, a analizom se dolazi do potrebne informacije o intenzitetu pojavljivanja, serioznosti i mogućim korektivnim mjerama u svrhu postizanja i održanja visoke razine kvalitete novinskog proizvoda. FMEA analiza je predstavljena u modificiranim tabličnim obrascima za proces proizvodnje novinskog proizvoda, a temeljem dobivenih rezultata su preporučene preventivne i korektive aktivnosti. Izvedbom preventivnih i korektivnih aktivnosti, uklanja se ili minimizira pojavljivanje nesukladnosti što u konačnici proces čini konkurentnim i otklanja nesukladnosti iz proizvoda.

The growing use of digital photo camera has influenced the development of different types of digital image files. Digital cameras and the users mostly use JPEG format. In this case quality stands for the accurate reproduction of the photographed element.In former times the quality of a photograph depended on the quality of the negative film and the photographic paper. Today, for most users, it depends on the sensor of the photo camera, type of file used and the print quality. JPEG format uses certain amount of compression which influences the file size and the image quality. This paper investigates the existence of the relationship between the subjective estimation and the objective results of different JPEG compression levels. The aim of this investigation is to determine the optimal compression level, at which the quality loss is not perceivable.