Pengaruh Level GCR dan UCR dengan Pengaturan Total Ink Limit Terhadap Penyimpangan Warna

Keakuratan warna abu-abu berperan penting dalam pengendalian kualitas warna suatu cetakan. Hal ini karena warna tersebut terdiri dari warna cyan, magenta dan yellow untuk melihat karateristik warna CIEL*a*b. Kalkulasi warna abu-abu ini dapat diatur dengan metode gray component replacement (GCR) dan under color removal (UCR) pada kegiatan pracetak dengan cara mengatur level total ink limit pada printer. Maka tujuan dari penelitian ini adalah untuk mendapatkan level GCR/UCR yang memiliki ∆E a*b terkecil dengan pengaturan total ink limit dan nilai deviasi warna (∆E a*b) dengan 3 variasi pengaturan total ink limit (200%, 300%, 400%) pada target warna FOGRA 27. Hasil penelitian ini menunjukkan bahwa komposisi CMYK ink coverage level GCR/UCR menunjukkan perubahan deviasi/penyimpangan warna (∆E a*b) neutral gray (mid tone) menggunakan FOGRA 27, memperlihatkan bahwa semakin tinggi total ink coverage maka semakin banyak tinta CMYK yang digunakan. Dan nilai deviasi warna (∆E a*b) terkecil adalah GCR Medium 400% dengan nilai ∆E a*b = 3,0 dan nilai penyimpangan warna UCR terkecil sebesar 1,67

Chromaticity Gamut Enhancement by Heptatone Multi-Color Printing

The present paper studies the chromaticity gamut of multi-color printing processes. Heptatone (7-color) printing - the most promising variant of multi-color printing - offers a significantly larger gamut than a conventional CMYK printing process, approaching CRT and film gamuts. The behavior of the process in the device-independent CIE-XYZ and CIE-L*u*v* colorimetric spaces is explored using the compound Neugebauer model developped for this purpose. A simple and straightforward Moiri-free separation process is proposed. The strong point of the proposed separation process is the fact that only 3 different screen layers are needed for any odd number of basic colors including black

Test targets 5.0: A Collaborative effort exploring the use of scientific methods for color imaging and process control

Test Targets is about scholarship that intimately involves faculty and students in the process of writing and publishing. It is a collection if research papers that require collaborative effort over a time span of three academic quarters. Initially, students learned metrology, color management system, and the use of test targets for device optimization and process control. As time goes by, students are encouraged to identify research topics, formulate methodologies, and carry out experiments and data analyses in order to have specific findings. - p.

Prevention of parturient paresis (milk fever) in dairy cows

Parturient paresis (milk fever) is a hypocalcemic disorder of dairy cows associated with the onset of lactation. In these studies, we have evaluated the ability of two calcitropic hormones, 1,25-dihydroxyvitamin D and parathyroid hormone, to prevent parturient paresis;Studies utilizing 1,25-dihydroxyvitamin D and its fluorinated analogues established that these compounds will prevent hypocalcemia if administered at the proper time prior to parturition. These studies confirm earlier work that the vitamin D compounds are effective solely by virtue of their ability to increase intestinal absorption of calcium. The studies also warn of possible renal toxicity that may accompany use of these compounds at high doses;Parathyroid hormone was found to increase plasma calcium concentration in periparturient cows through its activity on bone calcium resorption mechanisms, renal calcium conservation, and intestinal calcium absorption via its stimulation of the production of 1,25-dihydroxyvitamin D. These studies establish that parathyroid hormone can prevent parturient paresis in dairy cattle

Robust image steganography method suited for prining = Robustna steganografska metoda prilagođena procesu tiska

U ovoj doktorskoj dizertaciji prezentirana je robustna steganografska metoda razvijena i prilagođena za tisak. Osnovni cilj metode je pružanje zaštite od krivotvorenja ambalaže. Zaštita ambalaže postiže se umetanjem više bitova informacije u sliku pri enkoderu, a potom maskiranjem informacije kako bi ona bila nevidljiva ljudskom oku. Informacija se pri dekoderu detektira pomoću infracrvene kamere. Preliminarna istraživanja pokazala su da u relevantnoj literaturi nedostaje metoda razvijenih za domenu tiska. Razlog za takav nedostatak jest činjenica da razvijanje steganografskih metoda za tisak zahtjeva veću količinu resursa i materijala, u odnosu na razvijanje sličnih domena za digitalnu domenu. Također, metode za tisak često zahtijevaju višu razinu kompleksnosti, budući da se tijekom reprodukcije pojavljuju razni oblici procesiranja koji mogu kompromitirati informaciju u slici [1]. Da bi se sačuvala skrivena informacija, metoda mora biti otporna na procesiranje koje se događa tijekom reprodukcije. Kako bi se postigla visoka razina otpornosti, informacija se može umetnuti unutar frekvencijske domene slike [2], [3]. Frekvencijskoj domeni slike možemo pristupiti pomoću matematičkih transformacija. Najčešće se koriste diskretna kosinusna transformacija (DCT), diskretna wavelet transformacija (DWT) i diskretna Fourierova transformacija (DFT) [2], [4]. Korištenje svake od navedenih transformacija ima određene prednosti i nedostatke, ovisno o kontekstu razvijanja metode [5]. Za metode prilagođene procesu tiska, diskretna Fourierova transformacija je optimalan odabir, budući da metode bazirane na DFT-u pružaju otpornost na geometrijske transformacije koje se događaju tijekom reprodukcije [5], [6]. U ovom istraživanju korištene su slike u cmyk prostoru boja. Svaka slika najprije je podijeljena u blokove, a umetanje informacije vrši se za svaki blok pojedinačno. Pomoću DFT-a, ???? kanal slikovnog bloka se transformira u frekvencijsku domenu, gdje se vrši umetanje informacije. Akromatska zamjena koristi se za maskiranje vidljivih artefakata nastalih prilikom umetanja informacije. Primjeri uspješnog korištenja akromatske zamjene za maskiranje artefakata mogu se pronaći u [7] i [8]. Nakon umetanja informacije u svaki slikovni blok, blokovi se ponovno spajaju u jednu, jedinstvenu sliku. Akromatska zamjena tada mijenja vrijednosti c, m i y kanala slike, dok kanal k, u kojemu se nalazi umetnuta informacija, ostaje nepromijenjen. Time nakon maskiranja akromatskom zamjenom označena slika posjeduje ista vizualna svojstva kao i slika prije označavanja. U eksperimentalnom dijelu rada koristi se 1000 slika u cmyk prostoru boja. U digitalnom okruženju provedeno je istraživanje otpornosti metode na slikovne napade specifične za reprodukcijski proces - skaliranje, blur, šum, rotaciju i kompresiju. Također, provedeno je istraživanje otpornosti metode na reprodukcijski proces, koristeći tiskane uzorke. Objektivna metrika bit error rate (BER) korištena je za evaluaciju. Mogućnost optimizacije metode testirala se procesiranjem slike (unsharp filter) i korištenjem error correction kodova (ECC). Provedeno je istraživanje kvalitete slike nakon umetanja informacije. Za evaluaciju su korištene objektivne metrike peak signal to noise ratio (PSNR) i structural similarity index measure (SSIM). PSNR i SSIM su tzv. full-reference metrike. Drugim riječima, potrebne su i neoznačena i označena slika istovremeno, kako bi se mogla utvrditi razina sličnosti između slika [9], [10]. Subjektivna analiza provedena je na 36 ispitanika, koristeći ukupno 144 uzorka slika. Ispitanici su ocijenjivali vidljivost artefakata na skali od nula (nevidljivo) do tri (vrlo vidljivo). Rezultati pokazuju da metoda posjeduje visoku razinu otpornosti na reprodukcijski proces. Također, metoda se uistinu optimizirala korištenjem unsharp filtera i ECC-a. Kvaliteta slike ostaje visoka bez obzira na umetanje informacije, što su potvrdili rezultati eksperimenata s objektivnim metrikama i subjektivna analiza

Computer synthesis of spectroradiometric images for color imaging systems analysis

A technique to perform full spectral based color calculations through an extension of OpenGL has been created. This method of color computations is more accurate than the standard RGB model that most computer graphics algorithms utilize. By maintaining full wavelength information in color calculations, it is also possible to interactively simulate and display many important color phenomena such as metamerism and fluorescence. This technique is not limited to creating simple images suitable for interactive display, however. Using this extension, it is also possible to synthesize spectroradiometric images of arbitrary spatial and spectral resolution, for use in color imaging system analysis

Preferences and tolerances in color image reproduction

Observer preferences in the color reproduction of pictorial images have been a topic of debate for many years. Through a series of three psychophysical experiments we are trying to better understand the differences and trends in observer preferences for pictorial images, determine if cultural biases on preference exist, and finally generate a set of preferred color reproduced images for future experimentation and evaluation. The first experiment was a survey of observers rating the importance of commonly used image characteristics terms in correlation to color image quality. The data collected demonstrated that observer preferences remain relatively constant while judging color attributes between different media and for various image content. Experiment I also aided in the decision to utilize five dimensions of manipulation to generate preferred color reproductions, for Experiments II and in. The dimensions were, lightness (gamma adjustment to L*), contrast (sigmoid adjustment to L*), chroma (multiplicative factor on Cab* at a given hab), hue rotation, and color balance (additive adjustments to a* and b*). The second experiment was a rank order of image preference conducted at several research facilities around the world. The results yielded that statistical difference between peak preferences of image quality between cultures may exist but that the cultural difference is most likely not of practical significance for most applications. Furthermore, the shape of the preference curves across cultures is very similar so any cultural bias present is small. The final experiment was an adjustment experiment, in which observers were asked to generate the most preferred image possible. The observer variability (inter-observers) and repeatability (intra-observer) in generating preferred images were analyzed. The analysis of Experiment HI yielded that the intra-observer repeatability of an observer is about half of the variation between observers. Furthermore the analysis demonstrated that preferences on images with faces have a much tighter range of preference in comparison to images without faces. Finally, a cross analysis of Experiment II and HI was completed by the generation of preferred image sets from the results of the two experiments. The resultant images proved to be a good visualization of the range of variability in making preferred images from the color dimensions provided, and also visually demonstrated that the two techniques, (making one color adjustment at a time verses compounding color adjustments) of generating preferred images result in similar solutions

Test Targets 8.0: A Collaborative effort exploring the use of scientific methods for color imaging and process control

Publishing is both a journey and a destination. In the case of Test Targets, the act of creating and editing content, paginating and managing digital assets, represents the journey. The hard copy is the result or destination that readers can see and touch. Like the space exploration program, everyone saw the spacecraft that landed on the moon. It was the rocket booster that made the journey from the earth to the moon possible. This article portrays the process of capturing ideas in the form of digital data. It also describes the process of managing digital assets that produces the Test Targets publication

The Development of a Novel Blood-Brain Barrier, Organ-on-a-Chip System and the Identification of Erythrocytes as a Key Contributor to Age-Associated Neurological Decline

Advancements in modern medicine have greatly extended human life expectancy. However, with the onset of age-associated conditions such as Alzheimer’s disease, autoimmune disorders, and certain cancers, healthy aging is becoming an increasingly pressing issue. Blood exchanges between young and old partners demonstrate old blood can cause detrimental effect to the young animal, notably on the brain tissue. However, the complexity of blood makes it difficult to identify what role the individual factors play in the aggregate observed effect. This dissertation seeks to explore the potential effects of erythrocytes on the brain as we age. Erythrocyte morphology and rigidity changes as mammals age, altering their physical dynamics as they flow within the capillary bed. This impacts downstream biological events, such as the release of reactive oxygen species and hemoglobin, potentially compromising the blood-brain barrier. This work outlines the development of the next generation of blood exchange tools to further understand the role of blood in aging. Additionally, this work aims to develop a novel blood-brain barrier, organ-on-a-chip and to test the impact of erythrocytes on the brain. In doing so, we identify erythrocytes as a critical contributor to age-associated neurological decline