Hue Difference Research Articles

Comparison of hue differences measured by perception versus visual evoked potentials

Comparison of hue differences measured by perception versus visual evoked potentials

Effects of different surface finishing procedures and staining solution applications on lightness, chroma and hue of zirconia-reinforced lithium silicate glass ceramics

Aim: The aim of this study was to evaluate the differences in lightness (ΔL), chroma (ΔC), and hue (ΔH) of zirconia-reinforced glass ceramic (ZLS) samples of various thicknesses, which underwent different surface finishing procedures, after aging and staining solutions. Methodology: Sixty samples of ZLS blocks were produced in two different thicknesses (12x14x1 mm, n=30; 12x14x1.5 mm, n=30), and different surface treatments were applied to them (mechanical polishing or glaze; n=15). After polishing and glazing, all samples were cleaned using an ultrasonic cleaner for 10 minutes. Color measurements were taken using a spectrophotometer before and after autoclave aging and immersion in staining solutions (tea, coffee, and coke), and color values were calculated using the CIEDE2000 formula. The Kolmogorov–Smirnov, Shapiro, three-way ANOVA, and Tukey HSD tests were used for statistical evaluation. Results: The common effects of surface finishing treatment, staining solution, and thickness interaction on ∆L and ∆C values were found to be statistically significant (p<0.05), while the common effect on ∆H values was not found to be significant (p>0.05). The ∆L and ∆H values (5.06 ± 1.60 and 2.95 ± 0.61, respectively) were the highest in the groups with 1 mm thickness, mechanical polishing, and immersion in tea solution. The highest ∆C value (4.21 ± 0.35) was noted for the group with 1 mm thickness, mechanical polishing, and immersion in cola solution. Conclusion: Differences in material thickness and the staining solution affected the lightness, hue, and chroma of the ZLS samples. The difference in the surface finishing procedure affected the hue and chroma but not the lightness. How to cite this article: Korkmaz C. Effects of different surface finishing procedures and staining solution applications on lightness, chroma and hue of zirconia-reinforced lithium silicate glass ceramics. Int Dent Res 2024;14(2):57-67. https://doi.org/10.5577/intdentres.538

Exploring the CIEDE2000 thresholds for lightness, chroma, and hue differences in dentistry

ObjectiveTo evaluate the perceptibility and acceptability CIEDE2000 (KL:KC:KH) thresholds for lightness, chroma and hue differences in dentistry. MethodA Python-based program was developed to conduct a psychophysical experiment based on visual assessments of computer-simulated images of human teeth. The experiment was performed on a calibrated display. A 40-observer panel: dentists and laypersons (male and female; n=10), evalu- ated three subsets of simulated human teeth: the lightness subset (%∆L00 ≥ 98 %), the chroma subset (%∆C00 ≥ 98 %) and the hue subset (%∆H00 ≥ 98 %), using ∆E00 ≥ 5 units. A Takagi-Sugeno-Kang Fuzzy Approximation model was used as fitting procedure, and 50:50 % lightness, chroma and hue CIEDE2000 (1:1:1) and CIEDE2000 (2:1:1) perceptibility (PT00) and accept- ability (AT00) thresholds were calculated. Data was statistically analyzed using t-test (p < 0.05). ResultsThe 50:50 % PT00 for KL=1 were ∆L00=1.04, ∆C00=1.58 and ∆E00=1.01; and for KL=2 were ∆L00=0.51, ∆C00=1.58 and ∆E00=0.71. The 50:50 % AT00 for KL=1 were ∆L00=2.82, ∆C00=3.04 and ∆E00=2.66; and for KL=2 were ∆L00=1.40, ∆C00=3.04 and ∆E00=1.78. PT00 and AT00 ∆H00 may be considered no computable. A significant difference was found between CIEDE2000(1:1:1) and CIEDE2000(2:1:1), between lightness and chroma metrics, and between observer groups. No differences for lightness and chroma PT00 were found between male and female groups. ConclusionsIt is important to use PT00 and AT00 for lightness, chroma and hue specific to evaluate perceptual sensitivity for color changes in the tooth color space. AT00 for lightness and chroma are influenced by the observer's experience and gender. Males and laypersons show more tolerance for changes in chroma (∆C00) and in lightness (∆L00). SignificanceHue and chroma mismatch are more difficult to be accepted in dental color space.

Implication and Chemical Composition of Ancient Green Glass from Hong Nang Sida Temple in Champasak, Lao PDR

In southern part of Laos, once prospered under the Khmer Empire in the past, lots of ancient cultural heritage including Hong Nang Sida temple is still preserved. In this study, the chemical compositions, chromaticity and occurrences for five ancient green glasses excavated from Hong Nang Sida temple by Korea Heritage Agency were analyzed, and their implication was examined. As a result, all glasses showed some differences in hue, size, weight and shape, however, the compositions of flux, stabilizer and colorant revealed large differences. These have been identified as potash, soda and lead glass based on their composition. Considering the diversity of composition, it is interpreted that the production location and period of each glass was different. Meanwhile, if it estimates the inflow route reflecting the characteristics of glass, may be possible to infer regional or international exchanges in Laos at the time. This will be important data for understanding not only the ancient glass of Laos but also the glass artifacts technology and trade of Southeast Asian countries in the Khmer Empire cultural sphere.

Analysis of the Saliency of Color-Based Dichoptic Cues in Optical See-Through Augmented Reality.

In a future of pervasive augmented reality (AR), AR systems will need to be able to efficiently draw or guide the attention of the user to visual points of interest in their physical-virtual environment. Since AR imagery is overlaid on top of the user's view of their physical environment, these attention guidance techniques must not only compete with other virtual imagery, but also with distracting or attention-grabbing features in the user's physical environment. Because of the wide range of physical-virtual environments that pervasive AR users will find themselves in, it is difficult to design visual cues that "pop out" to the user without performing a visual analysis of the user's environment, and changing the appearance of the cue to stand out from its surroundings. In this article, we present an initial investigation into the potential uses of dichoptic visual cues for optical see-through AR displays, specifically cues that involve having a difference in hue, saturation, or value between the user's eyes. These types of cues have been shown to be preattentively processed by the user when presented on other stereoscopic displays, and may also be an effective method of drawing user attention on optical see-through AR displays. We present two user studies: one that evaluates the saliency of dichoptic visual cues on optical see-through displays, and one that evaluates their subjective qualities. Our results suggest that hue-based dichoptic cues or "Forbidden Colors" may be particularly effective for these purposes, achieving significantly lower error rates in a pop out task compared to value-based and saturation-based cues.

Effect of Wall Colors and Usage Rates on The Perception of Interior Spaces

In this study, it was aimed to determine the effects of colors and the usage rates in interior spaces on the spatial perceptions of users. With this objective, a living space was designed in a manner that would have three different colors (warm, neutral, and cool) and usage rates at 10%, 50%, and 100% and digital visuals were prepared. A total of 233 subjects participated in the research questionnaire and the data obtained were analyzed. In conclusion, it was determined that the living spaces which were colored at a low rate were perceived more positively according to the Semantic Differentiation Scales compared to the completely colored spaces. The spaces where warm and cool colors were used at the rate of 10% were perceived as more spacious and beautiful compared to the spaces where colors were used at the rates of 50% and 100%, whereas it was observed that when the values received were from positive to negative, they were listed in the form of 10% &amp;gt; 50% &amp;gt; 100%. Despite this, it was determined that the spaces where warm colors were used at the rates of 50% and 100% were perceived as more informal. Furthermore, it was observed that the differences in the colors used on the walls and the usage rates were changing according to gender and professions. Accordingly, it was determined that especially females and interior architects preferred, even more, the spaces with warm colors having a low usage rate.

Color induction in the restoration of architecture in historic city centers

AbstractIn the restoration of historic facades, specialists need to tackle the problem of colors applied to the ornamental elements that appear different on a facade than if they were isolated, because the colors of the surrounding surfaces influence them through color induction. This study evaluates the difference between the colors of ornaments observed in isolation, which we call nominal colors, and on different background colors, which we call induced colors, considering the historic color palette of Valencia as studied by the Color Research Group in Architecture of the Universitat Politècnica de València. The study consisted of the evaluation of 108 color pairs painted on physical cardboards, rated by 26 female students (average age 26.5), under natural lighting conditions, and using the Natural Color System (NCS) Color Atlas for the color match. Results indicate that induced colors have lower NCS blackness compared with nominal ones, and slightly higher or no NCS chromaticness shift. Nominal colors with low chromaticness exhibit an important hue induction effect and tend to shift to a hue that is located opposite to that of the background color in the NCS color circle, this effect being larger when the background has a warm color. The induction effect is larger when ornamental elements and background have similar nominal NCS blackness, and different nominal NCS chromaticness,with nominal hue difference no significant in the induction effect. The colors of ornamental elements that entailed greater induction were those with the lowest NCS chromaticness, and in the case of the background color, those with the highest chromaticness.

Dental and composite resin discoloration induced by different hydraulic calcium silicate-based cements: two-year in vitro assessment.

Few long-term studies assess the discoloration induced by hydraulic calcium silicate-based cement on dental structures. In addition, as far as we know, no long-term study has assessed the discoloration induced by these cement on composite resin. This in vitro study aimed to assess, during a period of two years, the discoloration potential of different hydraulic calcium silicate-based cements (hCSCs) on the enamel/dentin structure and composite resin restoration. A total of 40 enamel/dentin discs were obtained from bovine incisors, and 40 composite resin discs (10 mm in diameter × 2 mm thick) were fabricated. A 0.8 mm-deep cavity was made in the center of each disc and filled with the following hCSCs (n=10): Original MTA (Angelus); MTA Repair HP (Angelus); NeoMTA Plus (Avalon); and Biodentine (Septodont). An initial color measurement was performed (T0 - baseline). After 7, 15, 30, 45, 90, 300 days, and two years, new color measurements were performed to determine the color (ΔE00), lightness (ΔL'), chroma (ΔC'), hue differences (ΔH'), and whiteness index (WID). For enamel/dentin, the ΔE00 was significant among groups and periods (p<0.05). NeoMTA Plus had the greatest ΔE00. The NeoMTA Plus group had the greatest ΔE00 after two years for composite resin. Significant reduction in lightness was observed for all groups after two years (p<0.05). The most significant WID values were observed after 30 days for Biodentine (enamel/dentin) and MTA Repair HP groups (composite resin) (p<0.05). The hCSCs changed the colorimetric behavior of both substrates, leading to greater darkening over time. The Bi2O3 in the Original MTA seems relevant in the short periods of color change assessment.

Exosome Structures Supported by Machine Learning Can Be Used as a Promising Diagnostic Tool.

Principal component analysis (PCA) as a machine-learning technique could serve in disease diagnosis and prognosis by evaluating the dynamic morphological features of exosomes via Cryo-TEM-imaging. This hypothesis was investigated after the crude isolation of similarly featured exosomes derived from the extracellular vehicles (EVs) of immature dendritic cells (IDCs) JAWSII. It is possible to identify functional molecular groups by FTIR, but the unique physical and morphological characteristics of exosomes can only be revealed by specialized imaging techniques such as cryo-TEM. On the other hand, PCA has the ability to examine the morphological features of each of these IDC-derived exosomes by considering software parameters such as various membrane projections and differences in Gaussians, Hessian, hue, and class to assess the 3D orientation, shape, size, and brightness of the isolated IDC-derived exosome structures. In addition, Brownian motions from nanoparticle tracking analysis of EV IDC-derived exosomes were also compared with EV IDC-derived exosome images collected by scanning electron microscopy and confocal microscopy. Sodium-Dodecyl-Sulphate-Polyacrylamide-Gel-Electrophoresis (SDS-PAGE) was performed to separate the protein content of the crude isolates showing that no considerable protein contamination occurred during the crude isolation technique of IDC-derived-exosomes. This is an important finding because no additional purification of these exosomes is required, making PCA analysis both valuable and novel.

Effect of thickness of externally characterized stains on optical properties of high-translucency zirconia.

There is insufficient information about the effects of the thickness of externally characterized stains or glazes on CIELAB color parameters and the translucency parameter (TP) of 5mol% yttria partially stabilized zirconia (5Y-PSZ). The present study evaluated the effect of a thickness reduction of the externally characterized or glazed layer on its CIE2000 color parameters and TP00 of 5Y-PSZ. Twenty-eight specimens were sectioned from 5Y-PSZ blanks. Three brands of powdered stains (namely VI, SH, and IV) and a glaze (GL) were used to extrinsically stain the specimen surfaces (n = 7 per group). After measuring the final thickness and color, specimens of each group were carefully ground and finally polished. The reduced thickness was carefully controlled in decrements of 0.02mm on the characterized stains or glazed layers at each reduction cycle until the surface of the un-stained zirconia was exposed. The CIELAB color parameters of specimens were measured using a spectrophotometer. Subsequently, differences in lightness (∆L'), chroma (∆C'), and hue (∆H'), and TP00 values and color differences (ΔE00) were calculated using the CIEDE2000 formula to determine differences between the specimen and the un-stained zirconia at each reduction cycle. A paired-samples t-test, two-way mixed-design analysis of variance, and Pearson correlation coefficient were used to analyze the data (α = 0.05). There were no significant differences in lightness, chroma, hue, or TP00 values before or after glazing or after each reduction cycle of the glazed layer. Mean ΔE00 values ranged between 20.94 and 33.55 after applying the externally characterized stains. With a decreased thickness of the characterized stain layer, there were observed that significant decreases in ∆L', ∆H', ∆C', and ΔE00, and significant increases in TP00. Increasing the thickness of externally characterized stains decreased the lightness and caused the alternation of chroma and hue, whereas these phenomena were not observed in the glazed group. There was a slight change of CIE2000 color parameters and TP00 when the thickness of the characterized layer exceeded 0.06mm. The application and thickness of externally characterized stains can sensitively affect CIE2000 color parameters and translucency of 5Y-PSZ.

A new technique for stain-marking of seeds with safranine to track seed dispersal and seed bank dynamics.

Accurate tracking of seed dispersal is critical for understanding gene flow and seed bank dynamics, and for predicting population distributions and spread. Available seed-tracking techniques are limited due to environmental and safety issues or requirements for expensive and specialized equipment. Furthermore, few techniques can be applied to studies of water-dispersed seeds. Here we introduce a new seed-tracking method using safranine to stain seeds/fruits by immersing in (ex situ) or spraying with (in situ) staining solution. The hue difference value between pre- and post-stained seeds/fruits was compared using the HSV color model to assess the effect of staining. A total of 181 kinds of seeds/fruits out of 233 tested species of farmland weeds, invasive alien herbaceous plants and trees could be effectively stained magenta to red in hue (320–360°) from generally yellowish appearance (30–70°), in which the other 39 ineffectively-stained species were distinguishable by the naked eye from pre-stained seeds. The most effectively stained seeds/fruits were those with fluffy pericarps, episperm, or appendages. Safranine staining was not found to affect seed weight or germination ability regardless of whether seeds were stained ex situ or in situ. For 44 of 48 buried species, the magenta color of stained seeds clearly remained recognizable for more than 5 months after seeds were buried in soil. Tracking experiments using four species (Beckmannia syzigachne, Oryza sativa f. spontanea, Solidago Canadensis, and Acer buergerianum), representing two noxious agricultural weeds, an alien invasive plant, and a tree, respectively, showed that the safranine staining technique can be widely applied for studying plant seed dispersal. Identifying and counting the stained seeds/fruits can be executed by specially complied Python-based program, based on OpenCV library for image processing and Numpy for data handling. From the above results, we conclude that staining with safranine is a cheap, reliable, easily recognized, automatically counted, persistent, environmentally safe, and user–friendly tracking-seed method. This technique may be widely applied to staining most of the seed plant species and the study of seed dispersal in arable land and in disturbed and natural terrestrial or hydrophytic ecological systems.

Mars-TRP: Classification of Mars imagery using dynamic polling between transferred features

Expeditions on Mars and interest in research orienting around these exploration missions have been accelerating more than ever, recently. Due to lack of active human interference in Mars missions, processing and accurate classification of images taken by the rovers is a very essential part of the system. Proper identification of landforms governs the accessibility of the mobile rovers on Mars’ surface. Moreover, NASA has already collected over two million images from the planet, and more volumes are yet to arrive as these photographs serve as major documents for photogrammetry and studies based on remote sensing. Automatic labeling of incoming images and also making searching of the image database easier in the public interest requires highly accurate image classifiers. Deriving motivation from the above causes, this study intends to implement an efficient supervised multi-class image classifier for identifying Mars imagery. However, this objective is confronted by a major bottleneck. Most datasets that are accurately labeled, portray a highly skewed nature and insufficient data to train a deep model from scratch. The MSL surface imagery labeled dataset captured by the Curiosity rover, that has been considered for this study, is one such dataset with only 6691 images distributed unevenly into 25 classes. These obstacles are less signified in the existing literature and hence this paper addresses these challenges, outperforming the state-of-the-art metrics. Due to the absence of large data volume, a transfer learning based methodology was considered, using very deep convolutional networks pre-trained on ImageNet dataset. But images from Mars often involve a difference in hue, contrast and clarity when compared with images taken on Earth. Hence, the deep model was fine-tuned with our dataset and the extracted feature from the tuned neural network was used for the final classification. It was found that the results obtained from a single pre-trained model were not optimum and that ensemble approaches could unify many such results into a better result. Similar feature vectors were extracted from a few other pre-trained models. The whole setup converges into a dynamic routing module, a novel polling algorithm, which for each image, comes to an agreement about the best set of features while generating the output probability vector. The proposed approach is evaluated by several numeric metrics like accuracy, precision and recall, confusion matrices and roc curves, against the chosen individual pre-trained models and most prominent ensemble methods. Mars-TRP produces a test accuracy of around 88% in the standard test set of MSL surface dataset and an accuracy of 96% in the HiRise dataset, outperforming the individual pre-trained models, all the ensemble baselines and other existing approaches.

Colour discrimination thresholds vary throughout colour space in a reef fish (Rhinecanthus aculeatus)

ABSTRACTAnimals use colour vision in a range of behaviours. Visual performance is limited by thresholds, which are set by noise in photoreceptors and subsequent neural processing. The receptor noise limited (RNL) model of colour discrimination is widely used for modelling colour vision and accounts well for experimental data from many species. In one of the most comprehensive tests yet of colour discrimination in a non-human species, we used Ishihara-style stimulus patterns to examine thresholds for 21 directions at five locations in colour space for the fish Rhinecanthus aculeatus. Thresholds matched RNL model predictions most closely for stimuli near the achromatic point, but exceeded predictions (indicating a decline in sensitivity) with distance from this point. Thresholds were also usually higher for saturation than for hue differences. These changes in colour threshold with colour space location and direction may give insight into photoreceptor non-linearities and post-receptoral mechanisms of colour vision in fish. Our results highlight the need for a cautious interpretation of the RNL model – especially for modelling colours that differ from one another in saturation (rather than hue), and for highly saturated colours distant from the achromatic point in colour space.

Contributed Session I: FInD Color Detection and Discrimination in adults with and without color vision deficits: Preliminary results

Color vision deficits are important biomarkers, however, existing tests (e.g., Hardy-Rand-Rittler (HRR) & Farnsworth-Munsell 100 hue test (FM100)) are insensitive and time consuming to administer. FInD is a validated computer-based, generalisable, rapid, self-administered paradigm. We describe FInD Color Detection & FInD Color Discrimination and compare performance against HRR & FM100 tests in 9 color-typical and 4 atypical observers. Chromatic stimuli were presented on a luminance-gamma and cone-isolating calibrated display in 3 charts, each containing 4×4 cells. Each cell contained 1 (detection) or 2 (discrimination) gaussian chromatic patches in 8 Hz luminance noise. Observers reported whether a stimulus was present or whether the 2 stimuli were different in color, respectively. D' was calculated for short, medium or long wavelength-isolating stimuli (detection) or for hue differences in HSV space, centered on the 3 primary and 3 confusion axes at 50% and 100% saturation (discrimination). Detection and Discrimination thresholds for atypical observers were higher than for typical observers, with selective elevation of detection and discrimination thresholds corresponding to classic color deficits. FInD Color Detection & Discrimination tests rapidly and easily identify chromatic sensitivity deficits along the visual pathways and may provide a valuable diagnostic tool.

Printed paper-based devices for detection of food-borne contaminants: New device design and new colorimetric image analysis methods

In this paper, we introduce a paper-based microfluidic device design that allows liquids to flow at a constant rate through the channels. The device pattern is designed based on a flow rate control test. Our proposed device can be easily manufactured by a wax printer and be printed on filter paper. The primary function of the paper device is to measure the concentration of hazardous chemicals such as heavy metals and bacteria in liquids. We also propose two new image analysis metrics, hue difference and chroma magnitude difference, for analyzing the color of images as a means of identifying the concentration of heavy metals in solutions. In addition, we discuss in detail the image processing pipeline for analyzing the devices from the initial image capturing to segmentation and analysis. This paper also discusses future goals and possible directions to take, such as handling the device from different viewpoints.

Research on the colour preference and harmony of the two‐colour combination buildings

AbstractThis study used computer software to design building models with selected colour parameters based on a two‐colour pattern combination, which was then presented on a standard computer screen. Further, the two‐colour combination pattern was adopted to prepare building simulation pictures with 153 colour combinations. A total of six hues were extracted based on the Natural Colour System, and there were also 18 colour samples with different lightness and saturation degrees. The results of the study found that hue difference, lightness difference, chroma difference, and total colour difference have a significant effect on harmony. On the other hand, hue difference, chroma difference, and total colour difference have a significant effect on preference. It is worth noting that lightness difference and architectural colour preferences were negatively related. In addition, there was a high correlation between architectural colour harmony and preference.

Comparison of D65/10° and A/10° illuminant/observer systems for colour measurement of raw pork [pdf

BACKGROUND In pork colour measurements, the value of each parameter depends on the type of illuminant used. The spectra of D65 and A illuminants show great differences, with illuminant A having greater emission in the red part of the visible spectrum. Therefore, its application in the colour measurements of the pork longissimus muscle should result in larger changes in redness (Δa*) and hue angle (Δh°) and higher correlation between Δa* and Δh° and pH48 and WHC. The purpose of this study was to compare the suitability of the illuminant/observer systems D65/10° and A/10° for colour measurements of pork longissimus muscle, using the CIELAB and CIELCh systems. METHODS The study involved 168 samples of longissimus lumborum muscle taken from 168 carcasses (mean weight 90.2 ±6.0 kg) of pigs slaughtered on an industrial processing line. The moisture content, crude protein, intramuscular fat content, WHC, and pH48 were determined. Colour measurements using CIELAB and CIELCh scales were carried out with both D65/10° and A/10° illuminant/observer systems and reflectance measurements. The chromatic absorbance value at 525 nm (A525p) and the relative amounts of MbO2, MetMb, and Mb were calculated according to methods proposed by Krzywicki (1979) and AMSA (2012). Meat samples were illuminated and differences in the values of colour parameters (ΔL*, Δa*, Δb*, ΔC*, Δh°), chromatic absorbance at 525 nm (ΔA525p), and in the relative amounts of chemical forms of myoglobin (ΔMbO2, ΔMetMb, ΔMb) were determined. In addition, hue difference (ΔH) and total difference (ΔE) were calculated. RESULTS The values of correlation coefficients between moisture content (especially crude protein and intramuscular fat, and colour parameters) were low and often statistically insignificant. Higher and mostly significant values of correlation coefficients were found between colour parameters and WHC and pH48. The A/10° system resulted in higher values of correlation coefficients than D65/10° between (I) WHC, pH48 and (II) h°, Δa* and Δh°. At the same time, in the A/10° system the combined effect of the relative amounts of myoglobin chemical forms on the variation of h° values and the combined effect of changes (Δ) in their amounts on the variation of Δh° and ΔH and ΔE were greater than in D65/10°, with the greatest effect of these changes (Δ) in the amount of MetMb. CONCLUSIONS Replacement of the illuminant/observer D65/10° system with the A/10° system in colour measurements of raw pork longissimus muscle changed the proportion of pigments and the relative number of chemical forms of myoglobin in influencing the values of colour parameters, primarily h°. Therefore, using the A/10° system for colour measurements allows us to better capture the differences (Δ) in redness Δa* and especially in hue angle (Δh°), as well as hue difference (ΔH) and total difference (ΔE), with an increase in the relative amount of MetMb becoming the main determinant of these differences (Δ). At the same time, measurements using the A/10° system increased the correlation coefficients between WHC and pH48 and changes in redness (Δa*) and hue angle (Δh°). Therefore, the A/10° system compared to the D65/10° system may be more useful for measuring the colour stability of raw pork, especially the determination of Δh° and ΔH and ΔE. >.

Comparison of D65/10&deg; and A/10&deg; illuminant/observer systems for colour measurement of raw pork.

In pork colour measurements, the value of each parameter depends on the type of illuminant used. The spectra of D65 and A illuminants show great differences, with illuminant A having greater emission in the red part of the visible spectrum. Therefore, its application in the colour measurements of the pork longissimus muscle should result in larger changes in redness (&Delta;a*) and hue angle (&Delta;h&deg;) and higher correlation between &Delta;a* and &Delta;h&deg; and pH48 and WHC. The purpose of this study was to compare the suitability of the illuminant/observer systems D65/10&deg; and A/10&deg; for colour measurements of pork longissimus muscle, using the CIELAB and CIELCh systems. The study involved 168 samples of longissimus lumborum muscle taken from 168 carcasses (mean weight 90.2 &plusmn;6.0 kg) of pigs slaughtered on an industrial processing line. The moisture content, crude protein, intramuscular fat content, WHC, and pH48 were determined. Colour measurements using CIELAB and CIELCh scales were carried out with both D65/10&deg; and A/10&deg; illuminant/observer systems and reflectance measurements. The chromatic absorbance value at 525 nm (A525p) and the relative amounts of MbO2, MetMb, and Mb were calculated according to methods proposed by Krzywicki (1979) and AMSA (2012). Meat samples were illuminated and differences in the values of colour parameters (&Delta;L*, &Delta;a*, &Delta;b*, &Delta;C*, &Delta;h&deg;), chromatic absorbance at 525 nm (&Delta;A525p), and in the relative amounts of chemical forms of myoglobin (&Delta;MbO2, &Delta;MetMb, &Delta;Mb) were determined. In addition, hue difference (&Delta;H) and total difference (&Delta;E) were calculated. The values of correlation coefficients between moisture content (especially crude protein and intramuscular fat, and colour parameters) were low and often statistically insignificant. Higher and mostly significant values of correlation coefficients were found between colour parameters and WHC and pH48. The A/10&deg; system resulted in higher values of correlation coefficients than D65/10&deg; between (I) WHC, pH48 and (II) h&deg;, &Delta;a* and &Delta;h&deg;. At the same time, in the A/10&deg; system the combined effect of the relative amounts of myoglobin chemical forms on the variation of h&deg; values and the combined effect of changes (&Delta;) in their amounts on the variation of &Delta;h&deg; and &Delta;H and &Delta;E were greater than in D65/10&deg;, with the greatest effect of these changes (&Delta;) in the amount of MetMb. Replacement of the illuminant/observer D65/10&deg; system with the A/10&deg; system in colour measurements of raw pork longissimus muscle changed the proportion of pigments and the relative number of chemical forms of myoglobin in influencing the values of colour parameters, primarily h&deg;. Therefore, using the A/10&deg; system for colour measurements allows us to better capture the differences (&Delta;) in redness &Delta;a* and especially in hue angle (&Delta;h&deg;), as well as hue difference (&Delta;H) and total difference (&Delta;E), with an increase in the relative amount of MetMb becoming the main determinant of these differences (&Delta;). At the same time, measurements using the A/10&deg; system increased the correlation coefficients between WHC and pH48 and changes in redness (&Delta;a*) and hue angle (&Delta;h&deg;). Therefore, the A/10&deg; system compared to the D65/10&deg; system may be more useful for measuring the colour stability of raw pork, especially the determination of &Delta;h&deg; and &Delta;H and &Delta;E. >.

Peningkatan Kualitas Citra Termal Menggunakan Metode Blind Deconvolution

Temperature is a quantity that indicates the degree of heat of an object. The higher the temperature of an object, the hotter the object. Thermal imagery is an image created with thermal infrared spectrum that utilizes the temperature of an object. Sensing on this spectrum is based on differences in the temperature of the object and its emission power in the image which is reflected by the difference in hue or color. The sensor used in thermal images is noncamera based on scanning. In thermal imagery, there is a problem, namely blurred / blurred images that make it difficult to obtain information about objects. Blurred thermal images are caused by hot spots or rising temperatures. Thermal images often experience problems due to the large amount of diffraction fog in thermal imaging caused by the refractive index decreases as the wavelength increases. Blind deconvolution is a method that can be used to restore images that experience blur effects without having to know the value of the Point Spread Function (PSF). The process of improving the quality of thermal images is carried out using the blind deconvolution method which consists of 3 stages, namely finding the kernel value, looking for the convolution and estimation values ( ). Blind deconvolution method can be applied in improving the quality of thermal images by reducing the blur effect found in the image

Tooth discoloration induced by the different phases of a calcium aluminate cement: One-year assessment.

To assess the discoloration of teeth treated with the different phases of calcium aluminate cement (CAC), in comparison with the conventional CAC and mineral trioxide aggregate (MTA). Fifty bovine incisors were prepared and filled. Two millimeters of the filling was removed to fabricate a cervical plug with the following cements (n=10): CA(CaO.Al2 O3 ); CA2 (CaO.2Al2 O3 ); C12 A7 (12CaO.7Al2 O3 ); CAC and MTA. The initial color measurement was performed and after 7, 15, 30, 45, 90, 180, and 365 days new color measurements were performed to determine the color (ΔE00 ), lightness (ΔL'), chroma (ΔC'), hue differences (ΔH'), and the whiteness index (WID ). ΔE00 was significant for groups (p=0.036) and periods (p < 0.05). The greater ΔE00 was observed after 365 days for CAC (12.8). C12 A7 (7.2) had the smallest ΔE00 . ΔL' and ΔC' were significant for groups and periods (p < 0.05). ΔH' was significant for periods (p < 0.05). After 365 days, significant reduction in lightness was observed for all groups. For CA, CA2 , CAC, and MTA groups, the WID values decreased over time (p < 0.05). The tested cements changed the color behavior of the samples, resulting in greater teeth darkening over time. There is no long-term study assessing the discoloration induced by the different phases of CAC.