Journal of Printing Science and Technology
Online ISSN : 1882-4935
Print ISSN : 0914-3319
ISSN-L : 0914-3319
Volume 25, Issue 4
Displaying 1-5 of 5 articles from this issue
  • Unreversible Coding Methods
    Masayuki NAKAJIMA, Takeshi AGUI
    1988 Volume 25 Issue 4 Pages 191-201
    Published: July 30, 1988
    Released on J-STAGE: September 27, 2010
    JOURNAL FREE ACCESS
    This paper presents many unreversible data compression methods for color pre-press images. At first, two kinds of basic unreversible coding method, i.e., general digital data compression algorithms and orthogonal transformation methods like Descrete Cosine Transformation, are introduced. Next, main tasks about international standard for color image at ISO/JTC1/SC2 and CCITT SG VIII are described. The evaluating items for international standard and Adaptive Descrete Cosine Transformation (ADCT) algorithm, which has the highest posibility as the standard, are introduced. These unreversible methods are very useful for data compression of color pre-press image because extremely high compression ratio can be got using them.
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  • Takeshi AGUI, Masatake YOKOYAMA, Masayuki NAKAJIMA, Satoshi IGUCHI
    1988 Volume 25 Issue 4 Pages 202-207
    Published: July 30, 1988
    Released on J-STAGE: September 27, 2010
    JOURNAL FREE ACCESS
    Recently the nesting problems of general plane figures are becoming more important in several industrial field. This paper presents a method of deciding the optimal nesting for cutting out letters from an adhesive sheet. So far these problems have been solved through logistic methods by representing figures with pixels. In this paper, however, we decided relative positions of letters by using movable quantities calculated from coordinate values of letters' outlines. As the results, hight compression ratio was obtained.
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  • Yoshizumi YASUDA, Yasufumi EMORI, Hiroshi WASHIO
    1988 Volume 25 Issue 4 Pages 208-215
    Published: July 30, 1988
    Released on J-STAGE: September 27, 2010
    JOURNAL FREE ACCESS
    In images constructed by binany dots, spatical shift of individual dot is considered as a factor of degrading image quality, and especialy, it causes color fluctuations in resulted images. In this paper, the relation between dot-shifts and color fluctuations of the image has been quantitatively examined by computer simulation. For several typical dot patterns, color fluctuations derived from randum shifts of dots were calculated with and without UCR and plotted on UCS chromaticity diagram, and following conclusions were obtained. (1) Effect of dot shift in dot image on displayed color depends on the dot pattern type used. (2) Color fluctuations in print of Bayer type without UCR are larger than that of other types, but smaller with UCR. (3) As compared with tricolor printing, UCR puts a restraint on fluctuations of brightness of displayed colors, provided that dot shifts occur in each ink plate, but increase fluctuations of brightness, when dot-shifts occur in each dot.
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  • Hiroaki KOTERA
    1988 Volume 25 Issue 4 Pages 216-225
    Published: July 30, 1988
    Released on J-STAGE: September 27, 2010
    JOURNAL FREE ACCESS
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  • The Reaction of TAA with Tannic acid
    Tsuyoshi MORISHIMA, Kazuo FUTAMI, Masanori SAHARA, Tatsuya TOHYAMA
    1988 Volume 25 Issue 4 Pages 226-229
    Published: July 30, 1988
    Released on J-STAGE: September 27, 2010
    JOURNAL FREE ACCESS
    We investigated the reaction of titanium (IV) acetylacetonate complex (TAA) with phenolic compounds (tannic acid) mainly from the standpoint of colorimetry. The relations between the color (chromaticity, color tone, excitation purity) of their reactants and standing time of TAA coating were examined on the basis of the color measurement. We also attempted to decorate metal using their colored reactants. As the results, the films have the reddish yellow colors immediately after the coating of TAA. Their colors decreased with an increase in the standing time for TAA coating.
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