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O'Brien, Patrick C. "Effects of an active halftime rewarm-up, with carbohydrate supplementation, on player's blood glucose and second half performance during a collegiate soccer match." Thesis, Virginia Tech, 2017. http://hdl.handle.net/10919/79431.
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BACKGROUND: The half-time (HT) period of a soccer match is viewed as a period for recovery. Completely inactive and passive HT has implications on metabolic responses and subsequent performance during the initial phases of the second half. PURPOSE: Determine the effects of an active rewarm-up, compared to a passive period, at halftime on various measures of performance during the first 15-minutes of the second half using global positioning system (GPS) units. Identify the effects of the active versus passive HT period, with CHO beverage supplementation, on blood parameters. METHODS: Crossover design study, twenty collegiate male soccer players participated in two 90-minute soccer matches with passive rest (CON) or a moderate-intensity rewarm-up (RWU) during HT with CHO supplementation. Subjects received five fingerstick blood samples throughout the match (BG) and four subjects had serum insulin/BG taken three times during the match. RESULTS: RWU had significantly (p<0.05) higher measures for total distance, average speed, speed exertion, accelerations, HMP distance, decelerations, and EE during TI-4 half when compared to CON. No subjects experienced hypoglycemia. However, CON did have a significant drop in BG after HT and the lowest mean BG taken at 60-minutes. Tendency for CON and RWU to have HT insulin levels that were elevated and reduced, respectively. CONCLUSION: A passive HT period is not optimal, given its causal role in temporary physical performance deficits in the second half of soccer matches. The results provide a strong rationale for collegiate soccer players and teams to incorporate the 8-minute RWU into the HT regime to optimize second half performance.<br>Master of Science
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Nathanson, Desiree L. "Halftime Hydration and Snacking Practices in Collegiate and Professional Basketball and Football Players." Digital Archive @ GSU, 2010. http://digitalarchive.gsu.edu/nutrition_theses/8.
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Background: Sustaining a hydration state and energy status during competition is important for athletes, yet there is no current evidence in the literature that halftime hydration and snacking practices of basketball and football players have been assessed. Under ideal circumstances, proper hydration and food consumption practices should be followed by basketball and football players before, during and after practices and competitions because both sports involve fast rate of energy utilization with a concomitant increase in sweat production.
Objectives: This study aimed to improve our understanding of the halftime hydration and snacking practices used by basketball and football players at the collegiate and professional levels.
Methods: A total of 122 subjects filled out a halftime habit survey. The survey was completely anonymous to protect the identity of the athletes participating in the study. Athletic trainers and coaches of basketball and football teams, athlete agents, other athletic team employees, and players were contacted and provided with copies of a questionnaire to distribute to athletes. Data were analyzed using PASW Statistics 18. Data for height and weight were analyzed using descriptive statistics and all remaining data were analyzed using crosstabs and included a Chi Square Test.
Results: Of the beverages consumed by the 122 athletes surveyed, there was a statistically significant difference between sports in the consumption of Gatorade (n=89, p-.045), Powerade (n=41, p<.001), Powerade Zero (n=1, p=.020), and water (n=96, p=.049). There was a statistically significant difference between sports in the consumption of energy bars (n=62, p=<.001) and fresh fruit (n=41, p=.033). There was a statistically significant difference between sports in the purchase of snacks for halftime (p=.004) and the frequency of halftime snacking habits (p<.001). There is a statistically significant difference between sports in the halftime recommendations of teams for both hydration (p<.001) and snacking (p<.001). There is a statistically significant difference among sports in the influence of first half drinking practices on halftime hydration habits (p=.035). There is a statistically significant difference among sports in the extent of weight lost during a game (p<.001).
Conclusions: The results of this study show that athletes have the time and resources to drink and snack a the halftime break to replenish glycogen stores and rehydrate for the second half of the game. Athletes, whether by recommendation or by habit, consume a variety of beverages and snacks during the halftime breaks of games. It is still uncertain as to whether or not these hydration and snacking habits actually replenish glycogen stores and rehydrate the athletes for the second half of games. Future studies should be done to determine whether the hydration and snacking habits are maintaining hydration and sustaining blood glucose for better performance.
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Brennan, John Michael. "Show Design and Wind Arranging for Marching Ensembles." The Ohio State University, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=osu1397561909.
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Nazzaro, Alfonse. "Simulation of an electrophotographic halftone reproduction /." Online version of thesis, 1991. http://hdl.handle.net/1850/11241.
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Fu, Ming Sun. "Data hiding watermarking for halftone images /." View abstract or full-text, 2003. http://library.ust.hk/cgi/db/thesis.pl?ELEC%202003%20FU.
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Andersson, Anna, and Klara Eklund. "A Study of Oriented Mottle in Halftone Print." Thesis, Linköping University, Department of Science and Technology, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-9233.
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<p>Coated solid bleached board belongs to the top-segment of paperboards. One important property of paperboard is the printability. In this diploma work a specific print defect, oriented mottle, has been studied in association with Iggesund Paperboard. The objectives of the work were to develop a method for analysis of the dark and light areas of oriented mottle, to analyse these areas, and to clarify the effect from the print, coating and paperboard surface related factors. This would clarify the origin of oriented mottle and predict oriented mottle on unprinted paperboard. The objectives were fulfilled by analysing the areas between the dark halftone dots, the amount of coating and the ink penetration, the micro roughness and the topography. The analysis of the areas between the dark halftone dots was performed on several samples and the results were compared regarding different properties. The other methods were only applied on a limited selection of samples. The results from the study showed that the intensity differences between the dark halftone dots were enhanced in the dark areas, the coating amount was lower in the dark areas and the ink did not penetrate into the paperboard. The other results showed that areas with high transmission corresponded to dark areas, smoother micro roughness, lower coating amount and high topography. A combination of the information from these properties might be used to predict oriented mottle. The oriented mottle is probably an optical phenomenon in half tone prints, and originates from variations in the coating and other paperboard properties.</p>
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Bergman, Lars. "Using Multicoloured Halftone Screens for Offset Print Quality Monitoring." Licentiate thesis, Linköping : Univ, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-5573.
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Niederstadt, Dieter. "Halftone processing in printing with particular reference to flexography." Thesis, University of Hertfordshire, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.369228.
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Steinberg, Eran. "Analysis of random halftone dithering using second order statistics /." Online version of thesis, 1991. http://hdl.handle.net/1850/10976.
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Liu, Xiangdong. "Analysis and Reduction of Moire Patterns in Scanned Halftone Pictures." Diss., Virginia Tech, 1996. http://hdl.handle.net/10919/30304.
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In this dissertation we provide a comprehensive theory for the formation of a moire pattern in a sampled halftone image. We explore techniques for restoring a sampled halftone image with a moire pattern and techniques for preventing a moire pattern when a halftone picture is scanned. Specifically, we study the frequency, phase, and spatial geometry of a moire pattern. We observe and explain the half period phase reversal phenomenon that a moire pattern may exhibit. As a case study, we examine the moire patterns generated by a commercial scanner. We propose three restoration methods, including a notch filtering method, a simulation method, and a relaxation method. We also describe a moire prevention method, the partial inverse Fourier transform method. Finally, we propose a research agenda for further investigation.<br>Ph. D.
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Comeau, Richard G. "Prediction of screener-induced moire in digital halftone pattern generation /." Online version of thesis, 1990. http://hdl.handle.net/1850/11319.
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Linder, Tomas, Torbjörn Löfqvist, Coppel Ludovic Gustafsson, Magnus Neuman, and Per Edström. "Lateral light scattering in fibrous media." Mittuniversitetet, Avdelningen för naturvetenskap, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:miun:diva-18657.
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Lateral light scattering in fibrous media is investigated by computing the modulation transfer function (MTF) of 22 paper samples using a Monte Carlo model. The simulation tool uses phase functions from infinitely long homogenous cylinders and the directional inhomogeneity of paper is achieved by aligning the cylinders in the plane. The inverse frequency at half maximum of the MTF is compared to both measurements and previous simulations with isotropic and strongly forward single scattering phase functions. It is found that the conical scattering by cylinders enhances the lateral scattering and therefore predicts a larger extent of lateral light scattering than models using rotationally invariant single scattering phase functions. However, it does not fully reach the levels of lateral scattering observed in measurements. It is argued that the hollow lumen of a wood fiber or dependent scattering effects must be considered for a complete description of lateral light scattering in paper.<br>PaperOpt
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Nyström, Daniel. "High Resolution Analysis of Halftone Prints : A Colorimetric and Multispectral Study." Doctoral thesis, Linköpings universitet, Digitala Medier, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-15888.
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To reproduce color images in print, the continuous tone image is first transformed into a binary halftone image, producing various colors by discrete dots with varying area coverage. In halftone prints on paper, physical and optical dot gains generally occur, making the print look darker than expected, and making the modeling of halftone color reproduction a challenge. Most available models are based on macroscopic color measurements, averaging the reflectance over an area that is large in relation to the halftone dots. The aim of this study is to go beyond the macroscopic approach, and study halftone color reproduction on a micro-scale level, using high resolution images of halftone prints. An experimental imaging system, combining the accuracy of color measurement instruments with a high spatial resolution, opens up new possibilities to study and analyze halftone color prints. The experimental image acquisition offers a great flexibility in the image acquisition setup. Besides trichromatic RGB filters, the system is also equipped with a set of 7 narrowband filters, for multi-channel images. A thorough calibration and characterization of all the components in the imaging system is described. The spectral sensitivity of the CCD camera, which can not be derived by direct measurements, is estimated using least squares regression. To reconstruct spectral reflectance and colorimetric values from the device response, two conceptually different approaches are used. In the model-based characterization, the physical model describing the image acquisition process is inverted, to reconstruct spectral reflectance from the recorded device response. In the empirical characterization, the characteristics of the individual components are ignored, and the functions are derived by relating the device response for a set of test colors to the corresponding colorimetric and spectral measurements, using linear and polynomial least squares regression techniques. Micro-scale images, referring to images whose resolution is high in relation to the resolution of the halftone, allow for measurements of the individual halftone dots, as well as the paper between them. To capture the characteristics of large populations of halftone dots, reflectance histograms are computed as well as 3D histograms in CIEXYZ color space. The micro-scale measurements reveal that the reflectance for the halftone dots, as well as the paper between the dots, is not constant, but varies with the dot area coverage. By incorporating the varying micro-reflectance in an expanded Murray-Davies model, the nonlinearity caused by optical dot gain can be accounted for without applying the nonphysical exponentiation of the reflectance values, as in the commonly used Yule-Nielsen model. Due to their different intrinsic nature, physical and optical dot gains need to be treated separately when modeling the outcome of halftone prints. However, in measurements of reflection colors, physical and optical dot gains always co-exist, making the separation a difficult task. Different methods to separate the physical and optical dot gain are evaluated, using spectral reflectance measurements, transmission scans and micro-scale images. Further, the relation between the physical dot gain and the halftone dot size is investigated, demonstrated with FM halftones of various print resolutions. The physical dot gain exhibits a clear correlation with the dot size and the dot gain increase is proportional to the increase in print resolution. The experimental observations are followed by discussions and a theoretical explanation.
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Nyström, Daniel. "High resolution analysis of halftone prints : a colorimetric and multispectral study /." Norrköping : Department of Science and Technology, Linköping University, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-15888.
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Kalicinski, Simon. "The Effects of Dot Uniformity on Halftone Mottle inFlexographic Prints on Coated Board." Thesis, KTH, Skolan för datavetenskap och kommunikation (CSC), 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-150474.
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Flexographic print is a technology that is growing in popularity, especially in the packaging industry,due to its ability of printing on a wide variety of substrate types. Advances in ensuring good quality from flexographic processes have helped to bolster flexographic printing’s limited usage in the past decades. However, improving the quality of flexographic print products to a level that matches that of other mainstream printing methods is still needed. One common defect that affects flexographic print quality is mottling, which has been studied extensively in e.g. offset prints. At Innventia, a dependable method of calculating mottle numerically that highly correlates with subjective observations has been researched. This method has been applied into developing software called STFI-Mottle, which processes scanned images of halftones and returns average mottle values for them. In the case of this thesis, the goal has been to investigate what sort of characteristics in halftones caused by flexographiclead to a diminished halftone print quality on coated kraft board substrates. These characteristics were studied by examining dot uniformity in pre-printed samples of 30% halftone prints, then evaluating the data gathered with the ambition of finding a correlation between dot feature variations and print mottle. The mottle values that were used for analysis and discussion were computed using STFI-Mottle.The initial reasoning was that “white spots” found within the samples’ raster dots should be closely examined, as they might provide clues to explaining unexpected print mottle. The 30% halftone cyan regions of printed samples were scanned with a high-resolution Creo iQsmart3uniformity analysis was done with Matlab-based dot property calculation software. Thresholding was employed in image analysis in order to separate printed dots from unprinted substrate surface. A mottle evaluation was performed, focusing on the mottle values that were measured in the R channel using the same RGB images that were produced during scanning. Every data variable was compiled into a mean average for each sample, based on five to three signatures. Distribution histograms, simple linear regression and multiple linear regression were used to find meaningful correlations between measured data and mottle values.The study resulted in some significant correlations between variables established as quality indicators, but also showed possible new connections between variables that can express dot uniformity and print mottle. Some variables’ viability as mottle predictors has been rejected, while others are presented as new opportunities for study. The deeper implications of some of the variables analysed could not be investigated, but a foundation for a methodology to conduct similar research has been laid.Furthermore, the thesis has yielded an initial base of knowledge on new objective data that might be used as alternative measurements for quantifying print quality. In conclusion, the study indicated that there are dot uniformity variables that can be linked to print mottle, if not by themselves, then usingvarious combinations of them. Future research may determine the most accurate way that they can accomplish this.scanner. Next, a dot
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Oliver, Garth R. "Apparent quality of alternative halftone screening when compared to conventional screening in commercial offset lithography." Connect to this title online, 2007. http://etd.lib.clemson.edu/documents/1202500492/.
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Bougàs, Aristotelis Platon. "Influence of ink sequence on color's hue and saturation in four color halftone screen printing /." Online version of thesis, 1993. http://hdl.handle.net/1850/11080.
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Hansson, Malin. "Expanding textural expressions of synthetic non-woven." Thesis, Högskolan i Borås, Akademin för textil, teknik och ekonomi, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-23898.
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This degree work places itself in the field of textile design within printing and surface design. The primary motive is to explore methods of designing textural expressions of a non-woven polyester fabric which combine relief and printing techniques in order to design textiles with three-dimensional properties. The work explores possibilities on how to bring an aesthetic expression into a synthetic non-woven inlay fabric by using screen print, sublimation print and relief moulding towards an interior context. The purpose is to take advantage of the technical properties such as expansion, softness and stiffness of a non-woven polyester fabric into the design work. The design method consisted of a material-based pre-study to gain knowledge about non-woven materials and their reactions to heat, moulding possibilities and printing options. Further developments were done through workshops that explored frottage as design inspiration for final designs and gradations with halftones as a colouring method. The outcome of this degree work resulted in a collection of three textile pieces; a wall covering, a room divider and a sound absorber that are seen as prototypes for further development on how to give synthetic non-woven textiles an alternative aesthetic expression.
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Ellinwood, Jacquelyn S. "Comparison of four digital halftone screen (dither) patterns using quantitative analyses of the binary image microstructure /." Online version of thesis, 1989. http://hdl.handle.net/1850/11494.
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Chen, Ted. "A study of color image quality with respect to screen angle arrangement in multicolor halftone printing /." Online version of thesis, 1987. http://hdl.handle.net/1850/9674.
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Wang, Chihwe Jeffrey. "An evaluation of the effect of registration on GCR and conventional chromatic separation methods in multicolor halftone printing /." Online version of thesis, 1988. http://hdl.handle.net/1850/10324.
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Wu, Tuo. "Color variation of the gray balance target as related to color misregistration in multi-angle halftone color printing /." Online version of thesis, 1991. http://hdl.handle.net/1850/11224.
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Karthikeyan, Arvind S. "A study using a high-addressability inkjet proofer to produce AM halftone proofs matching Kodak approval in color, screening, and subject moiré /." Online version of thesis, 2009. http://hdl.handle.net/1850/11246.
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Vallat-Evrard, Louis. "Mesure, analyse et modélisation à l'échelle microscopique de points imprimés pour améliorer les solutions de lutte anti-contrefaçon." Thesis, Université Grenoble Alpes (ComUE), 2019. http://www.theses.fr/2019GREAI038/document.
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Les solutions pour lutter contre la contrefaçon permettant une sécurisation des produits dépendent des capacités de mesure à l’échelle microscopique de points imprimés. Les recherches explicitées dans ce manuscrit ont donc été consacrées au développement d’un équipement et de méthodes permettant de mesurer les imprimés à l’échelle microscopique. Un microscope en réflexion avec lumière polarisée a été associé avec un appareil photographique numérique. La matrice de Bayer a été retirée de la surface du capteur photographique et des images raw ont été enregistrées. La platine du microscope, l’appareil photographique, un photomètre et un thermomètre ont été contrôlés directement dans une interface logicielle développée en Python. Une méthode de mesure permettant d’élargir la gamme dynamique de reflectances mesurées a été proposée. L’appareil et les méthodes de mesures ont permis d’améliorer la précision et d’automatiser la mesure des points de trame à l’échelle microscopique. Les élargissements physique et optique des points de trame ont alors été séparés et analysés. Une méthode d’ajustement des pics de l’histogramme, correspondant à l’encre et au papier, avec une fonction Gaussienne a été proposée. Des algorithmes de seuillage ont été employés pour séparer l’élargissement optique et physique des points de trame. Une méthode objective d’évaluation des algorithmes de seuillage a été développée pour déterminer leurs performances sur les images de tramés. Cette méthode d’évaluation procède à une simulation des effets de la diffusion de la lumière et des défauts générés par l’imagerie afin de générer des images tests et images de référence. 30 algorithmes de seuillage de la littérature ont été évalués et ont présenté une dépendance avec le pourcentage de couverture de l’encre. Deux nouveaux algorithmes de seuillage ont alors été développés spécialement pour traiter les imprimés tramés. Le premier algorithme détermine le déplacement du pic correspondant à l’encre sur l’histogramme. Le deuxième algorithme proposé se base sur une pseudo-déconvolution permettant de prétraiter les images et se basant sur une séparation des effets de l’élargissement optique. Une caractérisation de l’élargissement optique et physique a alors été menée sur 2708 images d’imprimés tramés. Enfin, un modèle de l’élargissement physique et un modèle de l’élargissement optique des points de trame ont été proposés. Le modèle physique se base sur une génération de particules d’encre placées selon une fonction de probabilité et sur une fusion des particules d’encre. Le modèle a été évalué en considérant 43269 points de trame différents, mesurés automatiquement sur le microscope. Un nouveau modèle prédisant la réflectance des tramés a été développé, basé sur une double convolution avec deux fonctions différentes d’étalement du point. Ce modèle a permis de simuler de manière précise les effets principaux de la diffusion de la lumière dans le tramé, tout en simulant les effets de piégeage de la lumière à proximité des bords des points de trame<br>Applications in the field of product security and authentication to prevent counterfeiting rely on abilities of microscale measurements of printed dots. Thus, researches described in this manuscript have been directed toward the development of measurement methods and apparatus to characterize halftone dot at the microscale. A polarized reflection optical microscope has been adapted with a commercial digital camera. The Bayer matrix was removed from the surface of the camera and raw images were retrieved. The microscope stage, the camera, the photometer and the thermometer were controlled directly in a Python graphic user interface specifically developed. A high dynamic range capture method was proposed and tuned specifically to obtain richer information on the ink and paper regions. The measurement apparatus and methods helped improve the accuracy and automate the measurements of the halftone dots at the microscale. The physical and optical dot gains were then separated and analyzed. A Gaussian fitting of the ink and paper histogram peaks was proposed to measure automatically the ink and paper region reflectance as a function of the ink coverage. Thresholding algorithms were applied to separate optical and physical dot gain. An objective threshold evaluation method was developed in order to define the best threshold algorithms for halftone images. The method was based on a simulation of the optical dot gain effects and of the microscope distortions to obtain test images and ground truth images. 30 threshold algorithms from literature were evaluated and demonstrated dependency on the ink surface coverage of the halftones. Two novel threshold algorithms were then developed specifically to process halftones. The first threshold algorithm was based on the determination of the amount of ink peak shift. The second threshold algorithm proposed a pretreatment of the images by applying a pseudo-deconvolution strategy, removing the optical dot gain from the halftones. Characterizations of the optical and physical dot gains were then conducted analyzing 2708 different halftones. Finally, a physical dot gain model and an optical dot gain model were proposed in order to predict the halftone reflectances from raster to print. The physical dot gain model was based on the generation of single ink particles placed according to a probability mask and on a fusion of the ink particles. The model was evaluated with 43269 dot morphologies that were captured automatically on the microscope. A novel halftone reflectance model was proposed based on a double convolution with two different paper point spread functions. It allowed an accurate reproduction of the main effects of the light diffusion with, at the same time, an accurate reproduction of the light entrapment near the edges of the dots
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Mazauric, Serge. "Modèles spectraux à transferts de flux appliqués à la prédiction de couleurs sur des surfaces imprimées en demi-ton." Thesis, Lyon, 2016. http://www.theses.fr/2016LYSES064/document.
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La protection des documents fiduciaires et identitaires contre la fraude exige le développement d’outils de contrôle fondés sur des effets visuels sans cesse renouvelés, difficiles à contrefaire (même pour un expert ... de la contrefaçon !). Ce projet de recherche s’inscrit dans cette problématique et vise à apporter des solutions originales via l’impression de supports diffusants d’une part, et le développement de modèles de rendu visuel d’autre part. Les effets visuels recherchés sont des ajustements de couleurs entre les deux faces d’un imprimé lorsque celui-ci est observé par transparence devant une source lumineuse. Pour obtenir facilement des ajustements de couleurs quelles que soient les couleurs visées, il est capital d’avoir un modèle à disposition, permettant de calculer les quantités d’encre à déposer. Un modèle doit être capable de prédire les facteurs spectraux de réflexion et de transmission du support imprimé en décrivant les phénomènes de diffusion optique présents en pratique dans les couches d’encre et le support. Nous nous intéressons plus particulièrement aux imprimés translucides contenant des couleurs en demi-ton des deux côtés de la surface avec pour objectif de prédire le rendu visuel pour diverses configurations d’observation. Pour cela, nous proposons une nouvelle approche basée sur l’utilisation de matrices de transfert de flux pour prédire les facteurs spectraux de réflexion et de transmission des imprimés lorsqu’ils sont éclairés simultanément des deux côtés. En représentant le comportement optique des différents composants d’un imprimé par des matrices de transfert, la description des transferts de flux entre ces composantes s’en trouve simplifiée. Ce cadre mathématique mène à la construction de modèles de prédiction de couleurs imprimées en demi-ton sur des supports diffusants. Nous montrons par ailleurs que certains modèles existants, comme le modèle de Kubelka-Munk ou encore le modèle de Clapper-Yule, peuvent également être formulés en termes de matrices de transfert. Les résultats obtenus avec les modèles proposés dans ce travail mettent en évidence des qualités de prédiction équivalentes, voire supérieures, à celles qu’on retrouve dans l’état de l’art, tout en proposant une simplification de la formulation mathématique et de la description physique des échanges de flux. Cette simplification fait de ces modèles des outils de calcul qui s’utilisent très facilement, notamment pour la détermination des quantités d’encre à déposer sur les deux faces de l’imprimé afin d’obtenir des ajustements de couleurs<br>The protection of banknotes or identity documents against counterfeiting demands the development of control tools based on visual effects that are continuously renewed. These visual effects become thus difficult to counterfeit even by an expert forger ! This research tries to deal with that issue. Its objective is to bring new solutions using on the one side, the printing of diffusing materials, and on the other side the development of visual rendering models that can be observed. The visual effects that are sought-after are the color matching on both sides of a printed document when observed against thelight. To easily obtain a color matching, whatever the colors that are aimed for, it is essential to have a model that helps in calculating the quantity of ink to be left on the document. A model must be used to predict the spectral reflectance and the transmittance factors of the printed document by describing the phenomena of optical diffusion really present in the ink layers and in the document. We shall focus our interest especially on translucent printed documents that have halftone colors on both sides. Our goal here is to predict the visual rendering in different configurations of observation. To that end, we are offering a new approach based on the use of flux transfer matrices to predict the spectral reflectance and transmittance factors of prints when they are simultaneously lit up on both sides. By representing with transfer matrices the optical behavior of the different components present in a printed document, we see that the description of flux transfer between these elements is thus simplified. This mathematical framework leads to the construction of prediction models of halftone printed colors on diffusing materials. We also show that some existing models, such as the Kubelka-Munk or the Clapper-Yule models, can also be formulated in transfer matrices terms. The results that we get with the models used in this work make apparent identical prediction quality and in some cases even better ones to the ones found in the state of the art, while offering a simplification of the mathematical formulation and the physical description of the flux transfer. This simplification thus transforms these models into calculation tools that can easily be used especially for the choice of quantities of ink that must be left on both sides of the document in order to obtain color matching
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Liao, Sheng-Wei, and 廖盛偉. "Halftone to Continuous-tone Conversion Based on the Comparison Between an Original Halftone and Its Re-generated Halftone." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/88010641132659549193.
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碩士<br>國立成功大學<br>資訊工程學系碩博士班<br>95<br>In this paper, an inverse half-toning method based on the comparison between an original halftone and its re-generated halftone is proposed. Two halftone images coded by a half-toning algorithm are the same while their continuous-tone (contone) images are far more similar. A reconstructed contone image generated by an inverse half-toning algorithm should be similar to its original one. Moreover, the two contone images would be more similar if their halftones are the same. In this paper, therefore, the pixel value of a reconstructed contone image is adjusted according to the difference between its original halftone and its new one. All halftones in the paper are generated by error-diffusion method and the reconstructed contones are produced by lookup table method. Two kinds of adjusting methods are proposed in the paper. The first is to modify two pixel’s contone values by using the halftones of the pixel and its latter one. According to our observations, the tendency between the halftones and contones of the two pixels is similar, and their contone values are adjusted at the same time until their re-generated halftones are the same as their original ones. The second is to generate compensative values by using pre-computing lookup tables. In order to improve the performance, an image is classified into several categories by K-means algorithm. The table of every category is mapped from the difference between the two halftones to the corresponding difference between original and reconstructed contone images. Experimental results show that the proposed methods have better performance compared with others.
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Wang, Yue-Jonq, and 王羽仲. "Entropy coding on halftone image." Thesis, 1998. http://ndltd.ncl.edu.tw/handle/78231519051920106006.
Full text
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Chen, Yen-Hung, and 陳彥宏. "Watermarking techniques for halftone images." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/07411597739505146463.
Full textAbstract:
碩士<br>國立高雄應用科技大學<br>電子與資訊工程研究所碩士班<br>93<br>In the era of internet, documents in either color level or gray level are easily delivered in vast amount than before. To protect the copyright and ownership of those documents, digital watermarking is often used to prevent the illegal duplication. In this study, author has been interested in achieving data hiding of halftone images. Also, two watermarking algorithms were proposed to declare the authorship ( a binary mark ) of halftone images.
The first author’s research topic is rooted on self similarity in fractal theory. Because this watermarking algorithm using self similarity utilizes the stochastic property of halftone image, it is resistant to cropping and corruption due to human marking.
The secondary author’s research topic is to develop a lossless watermarking technique for halftone images. This proposed algorithm not only has the ability to achieve copyright protection, but also can exact recover the original halftone image with legal authorization. Experimental results show that the concept of pattern substitution in conjunction with an appropriate block cutting on a halftone image makes possible the positive recovery of the original halftone image after the extraction of a watermark.
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Chen, IYing, and 陳奕穎. "Fragile Watermarking on Halftone Image." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/80883391247498859271.
Full textAbstract:
碩士<br>輔仁大學<br>資訊工程學系<br>100<br>This thesis proposes a fragile watermarking on halftone image to verify if the halftone image was tampered or not, and to locate the tampered positions.
First, we compare two data hiding methods, Data Hiding by Smart Pair Toggling - Connection Selection (DHSPT-CS) and Data Hiding Look Forward Search (DHLFS). DHLFS shows a better performance than DHSPT-CS. Therefore, we design a new fragile watermarking method using DHLFS.
In this fragile watermarking method, we first partition the image into groups with secret key, and then embed the hashing code of a group into the next group as watermarking. The process will finish till all of the groups are embedded.
In the validation section, we extract the embedded watermark by even-odd parity on the blocks in all groups and calculate the hash code of all the groups. Finally, we compare the hash code and the watermark to verify whether an image was tampered or not, and provide the information of tempered locations.
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Chou, Te-Chih, and 周德智. "Data Hiding in Halftone Images." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/97214441498475782479.
Full textAbstract:
碩士<br>國立臺北大學<br>電機工程研究所<br>99<br>Image data hiding is a technique which can embed the secret in an image without affecting its quality such that one can extract the secret with efficient procedures. One class of these techniques is embedding the secret into images and extracting the hidden secret with complex computing. Another class is embedding visual secret pattern into two or more halftone images and extracting the hidden secret pattern in human visual system by overlaid of the share image. This thesis focuses on technique of the second class. All previous works are embedding the secret pattern via the so-called error diffusion processes which can convert gray-level images into halftone ones. However, all existing methods cannot work for the case that the input images are halftone. Motivated from this, we propose two schemes for hlaftone image data hiding. The first scheme hides the visual secret pattern into two halftone images without affecting the quality of the share image and improve the quality of the recovered secret pattern in white or black area. To prevent the secret exposed, we propose the second scheme. The second scheme prevent the secret exposed and keep the reasonable graphic quality of share image.
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Hung, Wei-Yi, and 洪位億. "Data steganograyphy for halftone image." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/81281526608298791901.
Full textAbstract:
碩士<br>國立勤益科技大學<br>資訊工程系<br>99<br>In this paper, we propose some data hiding method for halftone image. For the situation in which only the halftone image is available, we propose application of linear block embedded code (LBEC) to hide data by random location within a halftone image. The complementary and reduce the pixels are chosen to minimize the chance of forming visually modified. Our experimental results suggest that LBEC combined data hiding smart pair toggling (DHSPT) can maintaining good visual quality, and pair LBEC can hide a large amount of hidden data. The LBEC expect to hide n-k bit within a block.
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Chen, Bo-Kai, and 陳博凱. "Digital Image Hiding Using Halftone Image Technique." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/16960347846270720892.
Full textAbstract:
碩士<br>淡江大學<br>電機工程學系碩士在職專班<br>99<br>Data hiding technique is an important vector of network information communication and plays a role in security. This technique embeds secret information called a mark into host image to provide different purposes such as copyright protection, proof, and so on. Reversible data hiding technique provides not only secret data but also images being definitely in the decoding stage. This is highly desired in quality-sensitive imagery where even the minimal distortion introduced by embedding data is unacceptable since the reversibility helps to mark right decision during image analysis.
In recent years, researchers have developed some different reversible image hiding theories and methods based on image histogram modification and pixels difference. But high capacity of digital images is low and the loss of host information happens in traditional reversible image hiding method.
This study proposes a novel image hiding method based on histogram hiding and halftoning technique. This method uses reversible data hiding to embed error diffusion halftone image into original image for image secrecy. In image extract process, we use reversible data hiding to extract the halftone information, and hidden image is achieved from LUT inverse halftone. Experimental result shows that the performance of our method can hide high capacity of digital images, the stego-image is almost the same as the cover-image, and it can be reversible.
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Wu, Shih-tung, and 吳世通. "Inverse Halftoning and Watermarking of Halftone Images." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/62024988355940130483.
Full textAbstract:
博士<br>國立臺灣科技大學<br>資訊工程系<br>96<br>Halftones are dedicated for output devices, such as halftone printers
and palette-based displays that are capable of producing only a
limited number of colors. Halftones have been widely used in the
publishing applications, such as newspapers, books, magazines, etc.
In this thesis, inverse halftoning and watermarking of halftone
images are presented.
Inverse halftoning algorithm is used to reconstruct the gray image
from the input halftone image. Based on the recently published lookup
table (LUT) technique, a novel edge-based LUT method for inverse
halftoning is proposed for increasing the quality of the
reconstructed gray image. The experimental results demonstrate the
better image quality of the proposed edge-based LUT method when
compared to the Mese and Vaidyanathan algorithm.
Based on the proposed edge-based LUT inverse halftoning algorithm, a
color inverse halftoning algorithm is proposed. Color inverse
halftoning algorithm can transform color halfotnes to full color
image. Previously, Mese and Vaidyanathan proposed an efficient
LUT-based color inverse halftoning algorithm using the color
correlations among different color planes to improve the quality of
the reconstructed color images. The proposed algorithm first
demonstrates that although the Mese and Vaidyanathan algorithm
produces good quality reconstruction of color pixels in non-smooth
regions, the quality of reconstructed color pixels in smooth regions
may be degraded. Therefore, a new LUT color inverse halftoning
algorithm using an adaptive color correlation scheme is presented to
improve the quality of reconstructed color images. The experimental
results demonstrate the proposed algorithm achieves better
reconstructed image quality than that of the Mese and
Vaidyanathan algorithm.
Due to the growth of internet and digital media, the issue of data
hiding becomes more and more important since hiding data into
digitized images has many applications, such as authentication,
identification, annotation, and copyright protection, etc. Among
these digitized images, halftone images, text images, and mixed
text/halftone (MTH) images are three widely used binary document
images. A unified min-max transition (MMT)-based data hiding
algorithm for mixed text/halftone images is proposed to embed data
into MTH images without visual degradation. The experimental results
demonstrate that for MTH images, our proposed algorithm outperforms
the previous relevant algorithms. In addition, for embedding data
into halftone images or text images, our proposed algorithm is quite
competitive to the previously algorithms.
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Wu, Yeh-Kuang, and 吳業寬. "Development of Watermarking Scheme for Halftone Images." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/12153590889424902174.
Full textAbstract:
博士<br>淡江大學<br>電機工程學系博士班<br>97<br>As audio, video, images and other works become available in digital form, the ease with which perfect copies can be made, may lead to large-scale unauthorized copying which might undermine the music, picture, book, and software publishing industries. Watermarking has been considered for many copy prevention and copyright protection applications. Watermarking is the practice of hiding a message about an image, audio chip or meaningful logo within that work itself for protecting copyright. Two types of watermarking can be identified depends on specific application-driven requirements: (a) robust watermarking, and (b) fragile watermarking. For the aforementioned schemes, each watermarking scheme has its own considerations and limitations. In this dissertation, we are trying to develop robust and fragile watermarking schemes respectively and explore the combined watermarking schemes for the halftone images. Halftone images are widely used in the printing of books, magazines, newspapers and computer printers. Although there are only 2 tones, halftone images look like the original multi-tone images when viewed from a distance.
The first issue of this dissertation is to introduce the robustness and fragility of the watermarking system for digital gray-level image. The robust watermarking scheme is used for copyright protection and fragile watermarking scheme is used for content authentication. The second issue of this dissertation focuses on embedding the watermarks in the halftone images. The optimized watermarking scheme for halftone images based on dithering method is proposed. The multi-purpose watermarking is proposed for not only protecting copyright but also authenticating content. The optimized dither cells for watermarks embedding would be generated by the particle swarm optimization (PSO) with high transparency. However, in the experiments, we find that the proposed multi-purpose watermarking is not robust to the scaling attacks.
In the third issue of the dissertation, we would try to find the more robust watermarking scheme and discuss the image quality criterion for halftone images. In the method, the frequency domain based watermarks would be embedded to the watermarked images in order to enhance the robustness for scaling attack and call it hybrid watermarking scheme. And the human visual filter for the image quality criterion in halftone images is generated by PSO.
The last issue of this dissertation is to explore the advanced method for the proposed robust watermarking system for halftone images. The section aims at enhancing the privacy of the watermarking scheme that only one dither cell is necessary in the watermark extracting system. The support vector machine is adopted as the classification function in the watermark extracting stage, and the automatic resynchronization procedure for the watermark extraction stage with print-and-scan attacks is proposed to resist scan-and-print attacks.
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Wu, Sheng-Chu, and 吳升助. "A Robust Halftone Binary Image Hiding Method." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/59628752467910299247.
Full textAbstract:
碩士<br>朝陽科技大學<br>資訊管理系碩士班<br>91<br>With the rapid advancement of computer networks and multimedia technology, people can exchange and transmit a good many images through computer networks. However, the secure mechanism of an ordinary computer network, especially a wireless network, is insufficient so that the data transmitted on it would be easily intercepted. Thus, preventing the secret images transmitted on a computer network from being hacked by unauthorized users has become an interesting issue for many researchers.
In a halftone binary image, the patterns with a greater number of black pixels are used to display the dark regions in an image, and those with fewer black pixels are used to delineate the bright regions. Consider a halftone binary image I segmented into small image blocks. When one changes the image blocks to become other image I' where he exchanges the places of the pixels in each identical image block, I' and I still look very much alike. Based on the property, this thesis proposes a halftone-based binary image hiding (HBBIH) to process the halftone binary image embedding.
The proposed HBBIH method can provide a high embedding rate. In this embedding method, even though the error rate between the extracted secret image and the original secret image is great, the extracted secret image still can clearly depict the content of the original secret image. From the experimental results we observe that the error rate is not suitable for describing the unlikeness between two halftone binary images. Besides, if the stego image is damaged while being transmitted on the network, only the secret image blocks whose indices are damaged would be destroyed. Therefore, this method has a robustness capacity in the presence of noise on stego image.
When designing a successful image hiding system, some basic requirements such as imperceptibility, statistically undetectable, security, capacity, and robustness must be taken into consideration. In recent years, many techniques and methods about image hiding have been continually introduced. But, most of these techniques only focus on the former four requirements and neglect the requirement of robustness. Therefore, a robust image hiding method that also contains the feature of robustness is proposed in this thesis.
Generally speaking, when the amount of information that is embedded into a cover image grows, imperceptibility of information relatively becomes worse, and the exposure risk of embedding act becomes higher. In order to increase the capacity of information and also have imperceptibility of it, the information imperceptibility demanded in image hiding technique is not as strict as that demanded in digital watermarks technique. However, due to the limit of bandwidth for information transmission on network, users generally hope that loss data compression is processed in advance onto cover image to reduce the data before data transmission. Furthermore, when data is transmitted via Internet, it may be changed because of the influence from environment. As a result, an excellent image hiding technique should at least have certain degree of robustness against the damage of data that is not from intentionally attacks by others.
In order to increase image hiding capacity, VQ compression technique is used to do lossless compression toward secret images first, and the compressed data is grouped as belonging to several classes. Also, the method of discrete wavelet transformation — DWT is used to transform a cover image represented by space domain into a frequency domain image presented by frequency domain. Then, the data of some class in a secret image is embedded into the lower frequency sub-band that is not easily changed in a frequency domain image, while the part of other classes is embedded into middle frequency sub-band. Besides, when the compressed data of certain block B in a secret image is damaged, the system will recover them by using the blocks adjacent to B, which are hided in the lower frequency sub-band.
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TSAI, PEI-LING, and 蔡沛霖. "Application Analysis of Screen Printing Halftone Screen." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/d9659r.
Full textAbstract:
碩士<br>國立臺北科技大學<br>分子科學與工程系紡織技術及國際行銷產業碩士專班<br>107<br>The purpose of this study is to explore the analysis of the number of computer software for color-removal screen printing。With the change of fashion and the innovation of technology，the screen printing has been able to complete colorful photo printing from simple monochrome printing。The prepress work of printing is also closely related to the innovation of computer software。In this study，the color image was dissected for color image analysis，and the color of the drawing software was disassembled，and the number of meshes was divided into 65 lines，75 lines，and 85 lines，respectively，and the hand feeling and color performance were used as analysis and consumption。The client，the vendor，and the designer discuss separately。At the same time，analyze the most suitable color-removal data for the printing industry as a reference，and accelerate the combination of the fashion industry and the printing of traditional industries。At the end of the study，the three directions of the screen printing were summarized，which are: halftone screen data induction，computer color removal rules for spot color printing，printed hand feeling analysis and traditional printing and spot color printing market acceptance。
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HAO, CHEN CHIEN, and 陳建豪. "A Novel Halftone Watermarking Scheme Using Hilbert Curve." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/48009514915502000825.
Full textAbstract:
碩士<br>輔仁大學<br>資訊工程學系<br>98<br>In this thesis, we propose a novel embedding watermark technology and scheme which doesn’t require the original image in encoding and decoding process. The main purpose of this pepper is to embed high capacity watermark in halftone image with high visual quality, and to protect an image with a fragile watermark against malicious attacks. Our method use Hilbert Curve to divide the image into sub-images and exchange neighboring pixels of the sub-image to avoid too much pseudo pixels for embedding the watermark .Experimental results show that our proposal method performs much better than DHSPT (Data Hiding by Smart Pair Toggling).
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蔡昇融. "Enhanced identity document security by figurative halftone dots." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/11551530810612779430.
Full textAbstract:
碩士<br>國立臺灣師範大學<br>圖文傳播學系<br>95<br>To verify the linkage between the photograph and the personal data on the security document is the weakest point of authentication process and that is the reason why the alternation of photograph accounts for the major cause of fraudulent use. In order to withstand this serious attack, the figurative halftone dots designed by ordered dithering are applied to the output of portrait on the secured documents. While an identity document containing figurative halftone dots, its anti-counterfeiting feature can withstand the illegal alteration of photograph. In this paper an automatic method to generate a threshold matrix is developed to enhance the efficiency of halftone dots generation. On the other hand, the image quality is further improved by adjusting dots distribution and dot gain correction.
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Yeh, Kuan-Ting, and 葉冠廷. "A study of multi-purpose halftone image watermarking." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/10608432925510997740.
Full textAbstract:
碩士<br>淡江大學<br>電機工程學系碩士班<br>94<br>In many printer and publishing applications, it is desirable to embed data in halftone images for copyright control and authentication purposes. However, the robustness of the geometrical attacks in halftone watermarking is still a key problem.
In this paper, we proposed a multipurpose color halftone and halftone watermarking using embedding watermark into the pixel with complicated texture by wavelet transform based on the dithering technique in the halftone processing. For the color image. According to properties of the color model [R,G,B], we chosen the G level for embedded our robust watermark and B level for embedded our semi-fragile watermark. The Zernike moment is adopted to detect rotation and scale of the watermarked image. Experimental results show that watermarked image with good visual quality and the robust watermark is robust to the malicious attacks such as compress, corrupting, cropping, rotating, and scaling. The semi-fragile watermark can detect the regions where attacked by corrupted and cropped.
For gray-level image, the robust watermark is embedded by using two dither cells which produced different patterns during the halftone processing. We can find out the attacked regions of the image by using two new dither cells which are similar to the original dither cells. Robust watermark is robust to the malicious attacks such as corrupting, cropping, rotating, and scaling. The Correct DR value can close to 0.75 after the attack of print&scan. The semi-fragile watermark can detect the attacked regions and doesn’t need to modify the image. The advantage is to maintain the quality of the halftone image.
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Liao, Jing-Cheng, and 廖經晟. "Error Diffusion Kernel Design to Improve Halftone Quality." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/04564995140133948501.
Full textAbstract:
碩士<br>國立聯合大學<br>電子工程學系碩士班<br>94<br>The image quality of error-diffusion（ED）halftone can be improved by
estimating better error diffusion coefficients. In this paper, we propose two
algorithms to get better halftone quality, one is modifying the quantizer threshold
in ED to improve halftone, and the other is the ED model fitting of direct binary
search（DBS） halftone.
In the modifying of the quantizer threshold in ED to improve halftone, we
use the information of previous quantizer error, adjust it by constant modification,
and add the result to the quantizer input for getting better halftone quality.
Additionally, we adopt the IBLS algorithm to estimate an ED kernel, which will
yield similar halftone when it is used in the ED process. In the ED model fitting
of DBS, we utilize the halftone that produced by the DBS process, adjust the
error signal of ED process by iterative comparison, and finally using IBLS to
estimate the ED coefficient.
The experimental results show apparently that the ED coefficients so
obtained can resolve special problems of ED. For example, directional lines etc.
Furthermore, we also produce a series of ED kernels estimated from differential
resolutions of halftones to form a table, which cab be used for halftoning in
different resolutions via simply table lookup.
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林志鴻. "Study of the laser marking by halftone image." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/92020636190262227106.
Full textAbstract:
碩士<br>國立彰化師範大學<br>機電工程學系<br>95<br>Digital halftoning is the way to determine a suitable threshold value, if the value of the pixel is considered black then its output value is set to 1, otherwise it is considered white and its output value is set to 0. We can observe it use dot in dispersion to simulate a continuous-toned image; by adjusting the dispersion of the dots and fix their dimension. It is possible to improve the quality of the image. In this research we try to use Error-Diffusion method and use an alternate matrix to obtain halfton picture, go through the way of PSNR(Peak Signal Noise Ratio) and histogram to verify the better image output. The output value could be according to laser beam on or off and application in laser marking to display the halftoning image, and will observation the differential output marking image in different material as like PC、PE pad、pad of alumina with positive electrodes etc.
Keywords : Halftone Image、Error – Diffusion、PSNR、Histogram、Marking
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Hung, Jui-Hung, and 洪瑞鴻. "Error Correcting Watermarking on Ordered Dithered Halftone Images." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/71745557549510093432.
Full textAbstract:
碩士<br>輔仁大學<br>資訊工程學系<br>100<br>In this paper, we provide a watermarking technology on Ordered Dither Halftone Images. It can be used to detect images whether there has been tampered with, and to recover the tampered image if tampering rates less than a certain extent. The cover image is first partitioned into blocks, then a special scheme is provide to embed Reed-Solomon Code of the cover halftone image into the blocks.
This method can not only assures the integrity of the halftone image, but also can recover it for small modifications during communication.
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Chiu, Shang-Yung, and 邱尚勇. "JPEG Image Compression Technigues Based on Digital Halftone Printing." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/83103340050132875866.
Full textAbstract:
碩士<br>國立海洋大學<br>電機工程學系<br>90<br>Recently due to the fast progress of the personal computer technology, various computer peripheral equipments were developed and are widely used. The inkjet printer is one of the most popular computer peripheral. It has been used for printing text data and image as well, the most application is the image printing. Because the inkjet printer is a binary output device, when we want to print an 8-bit continuous-tone image approximately seven-eighth information in the original images will be lost during the halftoning process. Since we will eventually lose some information during the halftoning process when we print an image using inkjet printers, we can consider incorporating the information loss due to halftoning in the JPEG quantization stage. By doing so, we can reduce the required harddisk space for storing the image data.
In this thesis, we develop JPEG image compression techniques based on digital halftone printing. By incorporating the concepts of halftoning algorithm and the human visual system in the JPEG compression process, we can design a new quantization table that completely conforms to the JPEG image compression standard. We will show that the compression rate can be increase and excellent quality image prints can be obtained by using new quantization table in the JPEG image compression process. The quantization table design procedure proposed in this thesis does not presume a particular halftone algorithm, so all kinds of halftoning algorithm can be used to design the quantization table.
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Chen, Yong-chang, and 陳永昌. "Automatic Optical Proximity Correction of Halftone Phase- shifting Masks." Thesis, 1997. http://ndltd.ncl.edu.tw/handle/32871608198934915783.
Full textAbstract:
碩士<br>國立交通大學<br>光電工程研究所<br>86<br>In this thesis we develop a computer simulation program that can
simulate optical projection systems and can perform automatic
computer generation of a corrected mask pattern for any given
original mask pattern (traditional or halftone). The correction
is done to minimize the mismatch between the image pattern and
the target pattern. We also study the impacts of such mask
correction on the exposure-defocus latitude of the projection
system.
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Chiu, Peng-Yang Steven. "Automatic back-up registration for digital thermal halftone proofing." Thesis, 2002. http://hdl.handle.net/2429/13861.
Full textAbstract:
Proofing in the printing industry is a vital process of predicting and thus reducing
the costs of errors that may show up in the final prints. Digital thermal halftone
proofs are produced off-press and offer dot-for-dot match to the press sheet. To
produce such proofs with images on both sides of the proof sheets accurately
aligned, however, is typically done with skillful manual labor to control and
compensate for the thermal expansion of the images due to the step of laminating
images to the paper. The alignment of the images is called backup registration.
With the introduction of the second generation of thermal proofing media
known as direct-to-paper, the lamination step is unnecessary, thus, it is possible to
design an automatic backup registration method that can be integrated into many
of the existing digital thermal proofing devices.
This thesis proposes a novel approach to automatic backup registration by
detecting the orientation of the proof sheet (geometric detection), and then
adjusting the images on both sides (geometric correction). The geometric
detection uses the surface reflectivity differences between the proof sheet and its
background to determine the edge positions of the sheet. The geometric
correction shifts and rotates the images according to the detected edge positions
and various other factors.
The proposed algorithm is developed and implemented on Creo Products Inc.'s
Spectrum proofing device and numerous two-sided proof samples have been
produced to evaluate the precision of backup registration. Since all the samples
have demonstrated backup registration within the required 1mm precision and
the algorithm is implemented without additional hardware, there is a high
possibility of commercial application for the proposed method.
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Cheng, Ya-Wen, and 鄭雅文. "A Method of Watermark with Modified Hybrid Halftone Dots." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/51240981342945080775.
Full textAbstract:
碩士<br>國立臺灣師範大學<br>圖文傳播學系<br>101<br>In this research, a novel method is proposed to design watermarks with modified hybrid halftone dots. Due to the diversity of microstructures, the amplitude modulation (AM) halftone dots and frequency modulation (FM) halftone dots create different dot gains while printing, which affect the hidden effect of watermarks. Therefore, a density calibration chart is required to help calibrate watermarks with selected parameters. In order to balance the dot gains between AM and FM halftone dots, this research modified the micro-structure of AM halftone dots to make it similar to that of FM halftone dots. However, the different patterns of arrangement can still cause the distinctions of sampling requirements of duplicating equipment, to make the hidden watermarks emerge after duplication. This study employs the experimental method. A density calibration chart were printed out to observe the dot gain effect of modified hybrid halftone dots, which are composed by 1/4 AM and FM halftone dots. At last, the watermark, constituting of modified halftone dots, were printed onto paper, and using a copy machine to testify its effect. The results show that this method successfully balances the dot gain, and makes the watermarks emerge after copied. This technique not only makes the calibration process no longer necessary, but also provides better control of dot gain in any printing condition and long-run printing, to improve the quality of watermark presentations. In addition, the increased dispersion of modified AM halftone dots enhances the detection capability within highlight area and attains the better effect of printed watermarks.
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Huang, Win-Bin, and 黃文彬. "Researches on Compression, Halftone and Watermark in Multimedia System." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/38379450672806353842.
Full textAbstract:
博士<br>國立成功大學<br>資訊工程學系碩博士班<br>97<br>Recently, high visual quality and efficient compression rate are the most important issues in multimedia compression system. Besides, image authentication and copyright protection become more and more essential in our digital life. Four important topics, wavelet image compression, halftone image processing, the speedup of video compression and image watermarking, in multimedia system are presented in this paper. In the first research, the hardware implementation of a modified efficient SPIHT coder is presented. Set Partitioning in Hierarchical Trees (SPIHT) is a highly efficient technique for compressing Discrete Wavelet Transform (DWT) decomposed images. Though its compression efficiency is a little less famous than Embedded Block Coding with Optimized Truncation (EBCOT) adopted by JPEG2000, SPIHT has a straight forward coding procedure and requires no tables. These make SPIHT the more appropriate algorithm for lower cost hardware implementation. The modifications include a simplification of coefficient scanning process, a 1-D addressing method instead of the original 2-D arrangement of wavelet coefficients, and a fixed memory allocation for the data lists instead of a dynamic allocation approach required in the original SPIHT. Although the distortion is slightly increased, it facilitates an extremely fast throughput and easier hardware implementation.
In the second research, a hybrid neural network based method for halftoning and inverse halftoning of digital images is presented. The halftone image is performed by Single-Layer Perceptron neural network (SLPNN), and its corresponding continuous-tone image is reconstructed by Radial-Basis Function neural network (RBFNN). The combined training procedure produces halftone images and the corresponding continuous tone images at the same time. The PSNR performance and visual image quality of these contone images achieved is comparable to the well-known inverse halftoning methods. Moreover, the halftone images obtained are also visually good.
In the third research, the speedup of H.264/AVC coders by examining the predicted modes in a code block is described. In a rate-distortion optimized H.264/AVC (H.264/RDO) coder, the best mode with the minimal Lagrange cost is selected after calculating the rate-distortion (R-D) cost which simultaneously considers the distortion and the required number of bits in all possible modes. H.264/RDO coders achieve a good balance between bit rate and image distortion, but lots of additional computing power is required. The proposed method, called two-staged mode decision (TSMD), only executes the modes which might be the best mode used in H.264/RDO coders with other modes disabled. TSMD employs a two-staged decision process: the first stage is to predict some probable encoding modes according to the information when one encodes the preceding macro-blocks and video frames. The second stage refines the decision with either the pre-computed look-up-table or the pre-constructed Back-Propagation Neural (BPN) network. According to our experiment results, over 50% of the computation time is reduced with a small loss in Peak Signal-to-Noise ratio (PSNR) and a slight bit-rate is incremented which are not easily sensed by human eyes. All programs are based on the H.264/AVC standard reference software, JM 9.2.
In the last research, a feature-based robust digital image watermarking algorithm is proposed to achieve the goal of image authentication and protection simultaneously. The Hessian-Affine feature detector is at first adopted to extract characteristic regions of an image in the proposed watermark embedding scheme. Then the copyright watermark is embedded into these characteristic regions according to the local orientation of each pixel. Moreover, the remainder regions are applied for image authentication by using block-wise fragile watermarking method. Similarly, the proposed watermark detection scheme follows the above procedure to extract the copyright watermark and the authentic information independently and blindly from watermarked images. Various attacks are also applied to the watermarked images in order to examine the robustness of our algorithm. The experimental results show that the proposed watermarking algorithm can resist most removal and geometric attacks. Besides, changes of an image will be reflected in our hidden watermarks.
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chao-yi, Chang, and 張兆逸. "Watermarking of Ordered Dither Halftone Images by Bit Interleavin." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/87713688160820867897.
Full textAbstract:
碩士<br>輔仁大學<br>資訊工程學系<br>96<br>In this paper, we present a blind watermarking method to embed watermarks into dithered halftone images by pairing the sub-images derived from a new bit-interleaving method. The embedded watermark is thus undeletable. The search space of encoding is dispersed into the whole image through this new bit interleaving to great decrease the chance of disturbances in the local grey value. Combining the bit interleaving method with a variety of sub-image pairing methods, we can increase the distance of encoding and thus increase the robustness or embedding capacity. Totally speaking, the proposed method increases the embedding capacity with good visual quality, security and robustness against the cropping and tampering attacks.
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wei, Li-Ching, and 韋立青. "Inverse Halftone Using the Genetic Algorithm and A Codebook." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/12629630972199407764.
Full textAbstract:
碩士<br>立德管理學院<br>應用資訊研究所<br>93<br>In this research, the author proposes a method to inverse the halftone image using the genetic algorithm and a Codebook. There are several technology existed to inverse the halftone image. Most of them used template tables and calculated referred to the variation of the environment. However, none of them can provide the optimal templates and then the quality of inversed halftone can not be enhanced.
In This research, the genetic algorithm is proposed to search for the best template with weights.Also, the codebook is used in this application to enhance the inverse effect for in our method. The codebook is widely used in our method compression technology. Therefore, the combination of using the genetic algorithm and codebook is proposed in the research. In our experiments, our method outperforms of other methods.
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Kao, Yen-Hsiang, and 高彥翔. "Boundary processing on the watermark by hybrid halftone dots." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/80182588945021557515.
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