Wyniki wyszukiwania - BazTech

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Niwelacja wpływu przesyłu strumieniowego na jakość kolorystyki obrazów termowizyjnych

Onoszko K., Lis M., Kozierski P.

Pomiary Automatyka Kontrola

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2013

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R. 59, nr 10

1057--1060

PL

W artykule opisany został problem zmiany kolorystyki wynikający z procesu konwersji obrazu. Zmiany te zostały zauważone w czasie analizy termogramów, gdzie istotnym jest właściwe odwzorowanie barw, w celu prawidłowego określenia rozkładu temperatur. Korekcja obrazu oparta jest na obserwacji paska palety barw. W tekście przedstawiona jest krótka analiza statystyczna tego obszaru oraz zaproponowany jest algorytm, którego zadaniem jest niwelacja zaburzeń kompresyjnych.

EN

The paper describes the problem of color changes resulting from the image conversion process. These changes were observed during the analysis of thermograms (Fig. 1.). It is essential to proper representation of color, in order to properly determine the temperature distribution. Defining the transformation is based on the observation of the bar palette (Fig. 1. area 2). The second section presents the brief statistical analysis of the area. Standard deviations of the changes in individual lines are shown in Fig. 2, while changes of the nature of the RGB components in Fig. 3. On the basis of these observations, an algorithm whose task is to correct the disorder is proposed. The concept of improving the color scheme is based on the establishment of the correct color palette, and then replacing the original pixel values with the values of the newly created palette. The fourth section presents the results obtained by the algorithm correction. The last section presents the qualitative and quantitative changes in the image, as well as the places of their occurrence.

2

Combined achromatic and chromatic correction of color images

Lucchese L., Mitra S. K.

Zeszyty Naukowe. Telekomunikacja i Elektronika / Akademia Techniczno-Rolnicza w Bydgoszczy

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2006

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z. 9

25-35

EN

This paper advances a new algorithm for determining the color mapping between two images of the same object or scene taken under different illumination conditions. Yhe proposed algorithm compensates for differences in colors by separately equalizing their achromatic and chromatic components. The eqialization of the 1-D achromatic channel is carried out with a standard technique for gray-level images whereas the equalization of the 2-D chromatic channel is considered as a problem of image warping. This method can also be used to color calibrate a trichromatic sensing device, provided that a color chart is available.

PL

W artykule przedstawiono nowy algorytm służący do określenia odwzo-rowania kolorów pomiędzy dwoma obrazami tego samego obiektu lub sceny, uzyskanymi w różnych warunkach oświetleniowych. Działanie zaproponowa-nego algorytmu oparte jest na zasadzie kompensacji różnic kolorów, co wyko-nuje się niwelując różnice oddzielnie dla składowej achromatycznej i chroma-tycznej. Wyrównanie (niwelacja różnic) w achromatycznym kanale l-D jest dokonywane poprzez wykorzystanie standardowej techniki używanej w przy-padku obrazów czarno-białych, natomiast operacja wyrównania w chroma-tycznym kanale 2-D jest rozpatrywana jako problem deformacji obrazu. Przed-stawiona metoda może być również zastosowana do kalibracji kolorów czujni-ków kolorów, przy założeniu, że referencyjny rozkład kolorów jest znany.

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Correction of colour values of woven fabrics using changes to constructional parameters

Dimitrovski K., Gabrijelčič H.

Autex Research Journal

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2004

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Vol. 4, no. 4

186--192

EN

In practice it happens very frequently that yarn of certain fineness, which creates desired colour effect on the woven fabrics surface, is not available. In consequence an available yarn of different fineness has to be used instead, which can be observed on the woven fabrics as a colour deviation compared with the desired effect. The aim of this research is the possibility of colour values corrections of woven fabrics by changes of constructional parameters. Simulations of woven fabrics are used for this purpose. In the case described weft the yarn of higher fineness is substituted by the yarn of lower fineness and equal colour values. Three possible ways of colour values correction by changes of constructional parameters of the woven fabric are presented. In the first case, the colour difference is corrected by increase of the weft threads density, the second way of correction consists in the change of warp yarn fineness, and the third in decreasing of warp threads density. The basic purpose of all the three types of correction is the equally change of warp and weft contents in one colour rapport of the woven structure. In the experimental part of our work, the colour values L*, a* and b*, and colour differences DE*ab are investigated theoretically (using calculations on the basis of theoretical defined fractions, and L*, a*, and b* values of yarns), as well as spectrophotometrically, on the basis of printouts of simulations of woven fabrics prepared with the use of Arahne CAD system. Two ways of determination of colour values of simulations and three types of corrections are evaluated in the conclusions. It was find out that the correction with the increase of weft thread density is the most successful, and the DE*ab values are minimal.

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Latest results in digital color film restoration

Chambah M., Besserer B., Courtellemont P.

Machine Graphics and Vision

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2002

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Vol. 11, No. 2/3

363-395

EN

Motion picture is not only a theatrical art but also a vivid record of past life. Unfortunately, almost all color films amde since the 1950s are subject to fading that can be arrested only by storing prints at very low temperatures. Photochemical restoration of faded motion prints is impossible. Nowadays, the improvement of computer power allows us to expect digital restoration of motion pictures as acceptable rates. In this paper we present two orginal techniques for restoring faded color image sequences: an assisted and an automated one. The first method consists, in choosing a "reference image" from the sequence, after removing side absorptions introduced by the scanning process, adjusting its colors and contrast, then propagating the correction performed to the whole image sequence. The second method consists in reviving the colors of the image (color enhancement), then balancing them.