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Avijit Kar and Arun Kiran Pal
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Department of Printing Engineering, Jadavpur University, Salt Lake Campus, B-73-80, Plot No. 8, Salt Lake Bypass, LB Block, Sector III, Bidhannagar, Kolkata – 700106, West Bengal, India
Maintenance has become increasingly important in the production planning and management strategies of some companies. Overall equipment effectiveness is widely used for performance indicator in manufacturing industries around the world. Print productions are also not apart from problems related to the effectiveness of the machines/ equipment caused by the six big losses like breakdown losses, setup and adjustment losses, idle and minor stoppage losses, reduced speed losses, process defect losses and reduced yield losses. This can be seen with the frequency of failures that occurs in the machines because of several types of downtime so that the production target is not achieved. Total productive maintenance is the best method that can be used to improve the productivity and efficiency of the plant productions by using the machine effectively. Print production largely depends on the reliability, availability and maintainability of sophisticated printing machines. Aim of the present study is to determine quantitatively overall effectiveness and utilization of some printing equipment. The results of the effectiveness of web-offset printing machine and other ancillary equipment like computer-to-plate (CTP) machines and exposure unit are found to be below ‘world standard’ value of 85 %. The cause of low effectiveness value was due to poor performance and availability of the machines. Equipment utilization is also needed for the evaluation of printing equipment necessity, appropriateness and efficiency of the usage in print production. The proposed methodology may be able to increase the amount of working printing equipment by implementing proper maintenance planning. A significant increment of OEE (2.93 %) for web-offset printing machine is observed after implementation of proposed maintenance planning. The methodology is also validated by failure probability and reliability of the machines.
Keywords: overall equipment effectiveness (OEE), availability ratio, performance ratio, quality ratio, overall equipment losses (OEL)
JPMTR-2220 Original scientific paper | 169
Saorabh Kumar Mondal¹, Arpitam Chatterjee² and Bipan Tudu³
¹Department of Applied Electronics and Instrumentation Engineering, Haldia Institute of Technology, Haldia, India
²Department of Printing Engineering, Jadavpur University, Kolkata, India
³Department of Instrumentation and Electronics Engineering, Jadavpur University, Kolkata, India
Contrast enhancement is a popular image processing technique across different applications. Despite simplicity, many of the reported techniques lack in retention of original image features and cause different artifacts due to over or under enhancement. Such limitations cause problems in cases when the contrast enhancement is used prior to computer vision tasks. This paper presents a new approach of contrast enhancement where the color channel difference has been optimized using bat algorithm to obtain better contrast, improved naturalness and original image feature retention. The potential of the presented method has been assessed with the low contrast images from standard databases and found to be competitive to established models. At the same time the use of device independent color space provides more versatility of the presented method across different applications.
Keywords: image processing technique, image enhancement, color difference estimation, color space dynamics
JPMTR-2217 Original scientific paper | 170
Use of ArUco markers for image registration of photographs and influence of camera tilt on process performance
Veronika Štampfl and Jure Ahtik
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Chair of Information and Graphic Arts Technology, Department of Textiles, Graphic Arts and Design, Faculty of Natural Sciences and Engineering, Ljubljana, Slovenia
Image registration is widely used in the field of graphic technology, from printing processes to research. In order to successfully align two images, image sections must be recognized. In printing, simple linear markers can be used for alignment, while advanced visual systems use fiducial markers, such as ArUco markers, for specific position recognition. These can be applied to any surface and are quickly recognized by open-source algorithms. This gives us the ability to recognize any visually perceived surface and align it with the target image. This research focuses on the applicability of ArUco markers as reference points for image registration of photographs of flat, uniform surfaces. The camera tilt position was adjusted in four combinations to mimic the imperfect positioning of the camera relative to the observed surface. Twelve marker combinations were tested, varying in size, number, and positioning. Research has shown that ArUco markers are suitable as reference points for image registration, but in specific combination of size and position. General guidelines for their use have been established.
Keywords: position registration, photo-alignment, pattern recognition, fiducial markers
JPMTR-2216 Research paper | 171
Altynay Kadyrova¹, Marius Pedersen¹, Stephen Westland² and Clemens Weijkamp³
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¹Department of Computer Science, Norwegian University of Science and Technology, 2802, Gjøvik, Norway
²School of Design, University of Leeds, LS2 9JT, Leeds, UK
³Canon Production Printing Netherlands B.V., 5914 HH, Venlo, The Netherlands
Naturalness perception of 2.5D prints is content dependent and varies depending on the level of elevation used for reproduction. Moreover, various factors can influence the naturalness perception of 2.5D prints such as ink types, viewing angle, and illumination, to name a few. In this work, we focus on the effect of various ink types on the naturalness perception of 2.5D prints of wood images fabricated at 0.5 mm elevation. We found that the naturalness perception of 2.5D prints is influenced by the type of ink used. In particular, we found that 2.5D prints of wood images with matt inks were perceived by observers as more natural than with glossy inks. There were differences between the observers based on their level of expertise. The acquired findings can help to reproduce wooden content to be perceived as natural by using a specific type of ink.
Keywords: elevation, 2.5D printing, ink
JPMTR-2215 Professional communication | 172