OBJECTIVE The aim of the present investigation is to identify tooth shade among a group of Sudanese patients. MATERIALS AND METHODS Total number of patients was 227. Participant's age ranged from 15 to 72 years, which, was divided into four groups. The tooth included in the study was either right or left sounds maxillary central incisor. Vita Easyshade was used to select the tooth shade. Inve...

In the ceramic industry half-tone images are often generated from a small number of separations with the result that inks are printed over each other to achieve the final print. This study investigates whether an n-modified spectral Neugebauer-based model, which has been used quite successfully to predict reflectance for prints on paper substrates, can be used to predict the color of half-tone ...

Traditional methods of image permanence testing have tracked changes in image appearance (changes in density, color balance, and/or Dmin stain) with densitometric endpoint criteria. Densitometric filter sets were optimized for specific colorant systems, for example, the Status A filter set to measure chromogenic photographic materials like those processed in RA-4 chemistry. Modern digital print...

We developed a quantitative evaluation method for luminance and color uniformity on a display screen. In this paper, we report the analysis result of a viewer perception of luminance and color uniformity. In experiments, observers subjectively evaluated Mura images which were showed on the light emitting diode (LED) backlight screen by adjusting the luminance of each LED. We measured the lumina...

We focus on a recently proposed regression framework termed lattice regression, as applied to the construction of multidimensional color management look-up tables from empirical measurements. The key idea of lattice regression is that the construction of a look-up table should take into account the interpolation function used in its final implementation. Lattice regression solves for the look-u...

In this study, an image-based measurement system was developed for human facial skin colour, involving the development of a digital imaging system, collection colour from 60 subjects, generation different characterization models, and performance evaluation. The factors that affect characterization, including training datasets (two charts collected dataset), mathematical mapping methods (linear ...

Passerina del Frusinate is an autochthonous wine grape variety, which grows in the Lazio region that is currently being evaluated by local wine producers. In this study, colour properties (CIELab coordinates), bioactive compounds (total polyphenols and flavan-3-ols), HPLC-DAD phenolic acid profiles and in vitro biological activity of monovarietal Passerina del Frusinate white wines and the effe...

Using a paired comparison paradigm, various gamut mapping algorithms were evaluated using simple rendered images and artificial gamut boundaries. The test images consisted of simple rendered spheres floating in front of a gray background. Using CIELAB as our device-independent color space, cut-off values for lightness and chroma, based on the statistics of the images, were chosen to reduce the ...

For precision color matching, visual sensitivity to small color difference is an essential factor. Small color differences can be measured by the just noticeable difference (JND) ellipses. The points on the ellipse represent colours that are just noticably different from the colour of the centre point. Mathematically, such an ellipse can be described by a positive definite quadratic differentia...