This study investigated the colorimetric properties of different veneering materials on core materials. Standardized specimens (10 mm × 10 mm × 1.5 mm) reflecting four core (polyetheretherketone (PEEK), zirconia (ZrO₂), cobalt-chromium-molybdenum alloy (CoCrMo), and titanium oxide (TiO₂); thickness: 1.5 mm) and veneering materials (VITA Mark II, IPS e.max CAD, LAVA Ultimate and VITA Enamic, all...

A vehicle license plate recognition system extracts plate information from a digital image through image processing technology. License plate extraction (LPE) is the premise and key concept of license plate recognition systems. In China, two-row license plates are yellow and dirty. Thus, a novel license plate extraction method based on CIELab color space is proposed in this paper. The method in...

In this paper the effect of heat and ammonia treatment on the change in colour of oak wood (Quercus robur) and comparison of physical and mechanical properties were investigated. Wood specimens were made from heartwood and sapwood in dimensions 30×30×30 mm3. The specimens were subjected to heat treatment at 180oC and 230oC for 2 and 4 hours, others were treated by ammonia for 24 hours. After th...

The ultimate goal of realistic image synthesis is to generate computer imagery that is perceptually indistinguishable from its real-world counterpart. Many rendering techniques have been proposed, making tremendous progress to reach this goal. Now we are faced with two basic questions. How far we are from the goal? How well the existing techniques perform? No doubt a quantitative definition or ...

The design, production and characterization of tailored printable optical filters for visible optical communications are demonstrated. As result, the average color difference between the specified and the produced filters is 32.6, quantified in terms of CIELAB coordinates.

In this study, we present a method of chroma enhancement in the CIELAB color space and compare it with that RGB space. Color image using has disadvantage gamut problem occurs because conversion to is necessary display image. However, since based on human visual perception, quality resulting images expected be higher than space, introduce lookup table reduce calculation costs. Experiments compar...

In this study, the third order polynomial regression (PR) and deep neural networks (DNN) were used to perform color characterization from CMYK CIELAB space, based on a dataset consisting of 2016 samples which produced using Stratasys J750 3D printer. Five output variables including CIE XYZ, logarithm CIELAB, spectra reflectance principal components compared for performance printer characterizat...

Colour changes in Gradia Direct™ composite after immersion in tea, coffee, red wine, Coca-Cola, Colgate mouthwash, and distilled water were evaluated using principal component analysis (PCA) and the CIELAB colour coordinates. The reflection spectra of the composites were used as input data for the PCA. The output data (scores and loadings) provided information about the magnitude and origin of ...

This paper describes a method for constructing a lookup table relating a three-dimensional CMY coordinate system to CMYK colorant amounts in a way that maximizes the utilization of the printer gamut volume. The method is based on an assumption, satisfied by most printers, that adding a black colorant to any combination of CMY colorants does not result in a color with more chroma. Therefore the ...