We propose a method to improve existing color-difference formulas with additional visual data from color discrimination experiments. Color-difference formulas are treated as mean functions of Gaussian processes, and the visual data are considered as observations of these processes. Gaussian process regression is applied to predict unknown color differences. The method was evaluated with a combi...

Perceptual image distortion measures can play a fundamental role in evaluating and optimizing imaging systems and image processing algorithms. Many existing measures are formulated to represent “just noticeable differences” (JNDs), as measured in psychophysical experiments on human subjects. But some image distortions, such as those arising from small changes in the intensity of the ambient ill...

The evaluation of visual quality of color images has become very important and challenging task due to explosion of multimedia and graphics content on internet. An image exhibits loss in color information due to introduction of noise, blur, blocking artefacts, channel distortion and also during lossy compression. The primary goal of Image Quality Metric (IQM) is to measure emergence of such dis...

The main objective of this work was to test the performance of major formulas for assessment of small suprathreshold color differences in the blue region. The models examined include CIELAB color space based equations, including CIELAB, CIE94, CIEDE2000, CMC (l:c), BFD (l:c), and formulas based on more uniform color spaces, such as DIN99d, CAM02-SCD, CAM02-UCS, OSA-GP, and OSA-Eu in comparison ...

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 ...