Hue Shift Research Articles

Morphological and Structural Characterization of Algae-Based Nanoformulation

In the present study, confirmation of Spirulina platensis-mediated TiO2NPs formation was indicated by a noticeable shift in hue from white to light yellow. TEM analysis revealed the presence of irregularly distributed nanoparticles with sizes between 50 and 60 nm, while TEM analysis further disclosed a hexagonal structure. EDAX analysis identified elemental composition, with titanium peaks appearing at 4.5 to 5 keV, carbon peaks at 0.5 keV, oxygen peaks at 0.4 to 1.0 keV, silica peaks at 1.7 to 2.0 keV, zinc peaks at 8.0 keV, copper peaks at 7 keV, potassium peaks at 4 keV, phosphorus peaks at 3 keV, and iron peaks at 6 keV. These comprehensive findings confirm the successful synthesis of well-defined Spirulina platensis-mediated TiO2 nanoparticles and provide valuable insights into their structural and elemental characteristics.

Generic color correction for tone mapping operators in high dynamic range imaging.

One of the significant challenges in tone mapping is to preserve the perceptual quality of the tone-mapped images. Traditional tone mapping operators (TMOs) compress the luminance of high dynamic range (HDR) images with little to no consideration of image color information resulting into suboptimal colors. Existing color management algorithms require either manual parameter tuning or introducing lightness and hue shifts. The current study aimed to develop a color correction model in plausible agreement with the psychophysical phenomenon of color appearance perception for optimal color reproduction of tone mapped images. The proposed model leverages CIECAM16 perceptual correlates i.e., lightness, chroma, and hue. It is adaptive and entirely automatic while preserving the lightness of the tone-mapped image and maintaining the hue from the HDR image. Moreover, it does not require any gamut mapping correction algorithm in natural color reproduction. The effectiveness of the model was validated using objective and subjective methods. The experiments revealed that the model achieved optimal color reproduction in terms of the naturalness of the colors.

Colorimetric Analyses of the Optic Nerve Head and Retina Indicate Increased Blood Flow After Vitrectomy.

The purpose of this study was to evaluate the impact of vitrectomy and posterior hyaloid (PH) peeling on color alteration of optic nerve head (ONH) and retina as a surrogate biomarker of induced perfusion changes. Masked morphometric and colorimetric analyses were conducted on preoperative (<1month) and postoperative (<18months) color fundus photographs of 54 patients undergoing vitrectomy, either with (44) or without (10) PH peeling and 31 years of age and gender-matched control eyes. Images were calibrated according to the hue and saturation values of the parapapillary venous blood column. Chromatic spectra of the retinal pigment epithelium and choroid were subtracted to avoid color aberrations. Red, green, and blue (RGB) bit values over the ONH and retina were plotted within the constructed RGB color space to analyze vitrectomy-induced color shift. Vitrectomy-induced parapapillary vein caliber changes were also computed morphometrically. A significant post-vitrectomy red hue shift was noted on the ONH (37.1degrees ± 10.9degrees vs. 4.1degrees ± 17.7degrees, P < 0.001), which indicates a 2.8-fold increase in blood perfusion compared to control (2.6 ± 1.9 vs. 0.9 ± 1.8, P < 0.001). A significant post-vitrectomy increase in the retinal vein diameter was also noticed (6.8 ± 6.4% vs. 0.1 ± 0.3%, P < 0.001), which was more pronounced with PH peeling (7.9 ± 6.6% vs. 3.1 ± 4.2%, P = 0.002). Vitrectomy and PH peeling increase ONH and retinal blood flow. Colorimetric and morphometric analyses offer valuable insights for future artificial intelligence and deep learning applications in this field. The methodology described herein can easily be applied in different clinical settings and may enlighten the beneficial effects of vitrectomy in several retinal vascular diseases.

Color-appearance-matched data in high-dynamic-range luminance conditions

We report color-appearance-matched data under high-dynamic-range luminance conditions. The experimental method and apparatus proposed in a previous study [J. Opt. Soc. Am. A 36, 1940 (2019)JOAOD60740-323210.1364/JOSAA.36.001940] were used to measure perceptual color shifts in the R, G, B, Y, RB, BG, GY, and YR groups of 16 samples under four dual-illumination conditions at luminance levels of (300 and 4500cd/m2), (20 and 300cd/m2), (80 and 4500cd/m2), and (20 and 4,500cd/m2). We observed a decrease in lightness for all samples, and hue shifts toward blue in R, red in reddish YR, and green in BG samples when the luminance changed from low to high. Correlated changes in lightness and chroma, that is, an increase in lightness change and a decrease in chroma change under the highest luminance contrast (20 and 4500cd/m2), were observed for the Y, GY, and YR samples.

8‐3: Relationship between Metameric Color Matching and Hue Estimation

The metameric color matching and hue estimation experiments were conducted using four LED lightings having different spectral characteristics with five observers. The results showed that color mismatch was found in both experiments and hue shift was predictable using LMS‐based CIECAM16 model.

A Comparative Evaluation of Antimicrobial and Cytotoxic Efficacy of Biosynthesized Silver Nanoparticles and Chemically Synthesized Silver Nanoparticles Against Enterococcus faecalis: An In Vitro Study.

Introduction Effective root canal cleaning and sealing are essential for a successful endodontic procedure. For the purpose of disinfecting root canals, both herbal and non-herbal medications are recommended. This study aimed to analyze the antimicrobialand cytotoxic properties of biosynthesized silver nanoparticles (AgNPs)synthesized from Azadirachta indica/neem and chemically synthesized AgNPs from trisodium citrate (TSC) against oral pathogens to be further used as an irrigant in endodontic treatment. Materials and methods To synthesizeA. indicaAgNPs, powdered fresh A. indicaleaves were weighed, added to double distilled water, heated for 30 minutes, and then combined with silver nitrate solution. TSC was also used to create TSC AgNPs. X-ray diffraction (XRD), scanning electron microscopy (SEM), ocular observation, and the ultraviolet-visible light (UV-vis) spectrum were used to characterize the AgNPs. Studies were conducted on the extract's characteristics, including its cytotoxicity and antibacterial activity. Results The hue shift and peak on the UV-vis spectrophotometer were signs that AgNPs were forming. The XRD pattern showed that the sample included crystalline AgNPs, mostly spherical ones. By using SEM, the presence of AgNPs was also verified. AgNPs that were synthesized showed antimicrobial efficacy against Enterococcusfaecalis. Compared to chemically synthesized AgNPs, A. indica AgNPs showedlower minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values, a bigger zone of inhibition (ZOI), and less cytotoxic action. Conclusion This study demonstrates the minimal cytotoxicity and antibacterial activity of A. indica AgNPs against E. faecalis. This suggests that they might also be employed asroot canal cleaners. Before experimenting with animals or cell lines in clinical trials for endodontic treatment, further research should be done.

Characterizing Probiotic Lactic Acid Bacteria from Buffalo Milk Fermentation (Dadih) for Beef Biopreservation

Beef is a perishable food that can be naturally preserved using antimicrobial chemicals in a procedure known as biopreservation. Probiotic bacteria, or bacteria with the ability to create antimicrobial metabolites, are known as lactic acid bacteria. Fermented foods such as dadih, or fermented buffalo milk, from West Sumatra, Indonesia, contain lactic acid bacteria. This study aims to explore the existence of probiotic lactic acid bacteria in dadih and the effectiveness of utilizing lactic acid bacteria metabolites as biopreservatives in beef for nine days at 4 °C. The DK1 strain of lactic acid bacteria showed the most antibacterial metabolite activity against Salmonella sp. (11.5 mm) and Escherichia coli (13 mm) among the three isolates examined. Probiotic characteristics set the DK1 isolate apart; resistance test results showed over 106 CFU/mL, pH 2–4, a temperature range of 25 °C to 45 °C, and 0.3% bile salt. DK1 isolates tested positive for auto-aggregation 89.2% of the time. The co-aggregation test results for Salmonella sp. and E. coli reveal 46.9% and 53.1%, respectively. The findings of the bio preservation showed that, overall, treated beef contained fewer E. coli and other microorganisms than untreated meat. Furthermore, compared to control beef, metabolite-treated meat showed a shift in hue and a lower, more constant pH value.

Stability and Dependability of Built Building Structures and Factors Contribute to Efflorescence

Modern pigmented concrete products in the early 1950s, coloured concrete products have opened up new possibilities in the field of building and landscape design. Ironically, these coloured concrete products have also opened the door to a new visible phenomenon that is known as efflorescence. The unfortunate reality is that hue shifts in the completed goods are always the adversary, regardless of how carefully the raw materials are chosen or how conscientiously the manufacturing standards are adhered to. Calcium carbonate efflorescence is the likely cause of the colour inconsistencies that are sometimes referred to as fading in many instances. One might wonder how efflorescence might still occur even though the manufacturer has supposedly done everything properly, such as using excellent materials, having a good mix design, exceeding the strength requirements, and meeting the manufacturing schedule. This mind-boggling issue may be answered if one were to do in-depth research into the process underlying efflorescence. Even though a great deal of effort has been put into researching the phenomenon of efflorescence, and even though researchers from all over the world have come to a large extent of an agreement on the mechanism behind the formation of efflorescence, there are still no effective methods that concrete manufacturers can use to prevent the formation of efflorescence on finished concrete products.

A mathematician knits an afghan and counts the number of possible patterns

The Hue Shift afghan consists of 100 squares knit with 10 colours in a manner determined by a diagram. How many ways can you knit a Hue Shift afghan? What makes an afghan a Hue Shift is defined. Then the number of different afghans is determined up to symmetry considering colour order, stripe order, and direction of knitting for each square.

Didactic Panel Illustrating Light Exposure Effects

Abstract A small framed display panel holds a selection of paper and media common in works on paper plus a set of Blue Wool Standards. The selection of materials and design of the panel including two types of glazing are presented, and the purpose of the panel as a tool for explaining the effects of light on materials is discussed. At the centre of the panel are watercolour samples prepared using primary colours in mixed washes that illustrate hue shift resulting from selective fading of one colourant.

Hue-Preserving Color Transforms for LED Wall Virtual Production Workflows

Virtual production using light-emitting diode (LED) wall display technology is gaining popularity in the entertainment industry to produce motion pictures, episodic television, live broadcast, and esports content. This new paradigm typically uses one or more large LED displays that contain millions of individual LEDs that are used to display a virtual background and/or foreground objects from a virtual scene that is simultaneously captured by the digital photographic camera on set, resulting in the so-called “in-camera visual effects.” In a virtual production workflow, digital cameras capture the actors and objects on the set in the foreground while simultaneously capturing the image shown on the LED wall behind the actors. Realtime video game rendering engines update the image shown on the LED wall to compensate for changes in camera location, camera pose, and lens focal length. Modern digital camera workflows typically include color transforms that were not designed to accurately render the large areas of saturated colors that are possible when capturing the image shown on an LED wall. Some examples of a hue shift that can occur in typical workflows are blue to cyan, red to pink, red to orange, and green to yellow. We found that these hue shifts can occur dynamically while racking focus to and from the LED wall and also statically when the LED wall is kept out of focus, which is a common technique that is used to minimize moiré artifacts. This article explores a simple modification of these common color transforms to preserve the hue of the scene while also creating a similar look to the existing color transforms.

Theoretical design, prediction and synthesis of a magenta dye SCFX-AYRL for sustainable coloration of natural fibers in SCF-CO2

A special magenta dye SCFX-AYRL with dichlorotriazine as reactive group, designed as one of supercritical trichromatic dyes, was successfully synthesized for sustainable coloration of natural fibers in supercritical fluid of carbon dioxide (SCF-CO2). The products were characterized and tested by FT-IR, 1H NMR, LC-MS, EA and Uv-Vis spectra. Moreover, Gaussian software was also employed to assist a theoretical design of the dye and its precursor, such as the optimization of structure conformations, the calculation of frontier molecular orbitals and parameters, and the prediction of characteristic absorption wavelength. The obtained results show that the molecular structure and color characteristics of the synthesized dye well met the expected theoretical design and calculations. Particularly, the powerfully excited molecular orbitals facilitated the first electron transition from the highest occupied orbital (HOMO) to the lowest unoccupied molecular orbital (LUMO) by contributing characteristic singlet absorption bands for the precursor and its target dye. Moreover, an energy gap (ΔE) calculation between the LUMO and the HOMO was performed to predict color hue shift, and was well consistent with experimental detects. A successful application of the special dye on natural protein fibers was observed for eco-friendly coloration in SCF-CO2 with high color strength, fixation efficiency over 90.0 %, as well as high brilliant color and fastness.

Achieving tunable luminescence in rare earth free IRMOF-3 through post synthetic modifications by judicious choice of organic linker

Owing to the high cost of rare earth ions/lanthanides, associated health hazard, mining issues and transport constrain, there is an urgent need of designing rare earth free functional materials. Globally lot of thrust has been given on designing cost effective lanthanides free phosphors for light emitting diodes. In addition to cost efficient and environmentally benign, these lanthanide free phosphors are free from doping induced defects, strain and distortions. Herein, two new functionalized Zn based isoreticular metal organic frameworks (IRMOFs) namely; IRMOF-SMA (sulfamic acid) and IRMOF-DPC (diphenyl phosphonic chloride) were synthesized via post synthetic modification (PSM) using IRMOF-3 for investigating the color tunable luminescence. The synthesized materials were characterized using powder X-ray diffraction (powder XRD), thermogravemetric analysis (TGA), fourier transformed infrared (FTIR), and nuclear magnetic resonance spectroscopy (NMR), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). For the first time, we have demonstrated tuning of intrinsic violet emission from pristine IRMOF-3 via PSM employing organic ligands viz. SMA and DPC. SMA leads to slight shift in emission hue from violet to blue but DPC leads to giant color shift from violet-blue to white light. The shift is correlated to electro negativity difference between sulfur and phosphorus, respectively, in SMA and DPC. Color correlated temperature evaluated for DPC linked IRMOF-3 was more than 5500 K suggest being bluish white (cool white). Enhancement in luminescence lifetime also observed with PSM MOFs compared to pristine sample owing to lowering of non-radiative transitions. This work opens up new avenues in the field of exploring MOFs for lanthanide optoelectronic devices and light emitting diodes and further tuning the light via PSM strategy.

High Molecular Weight λ-Carrageenan Improves the Color Stability of Phycocyanin by Associative Interactions

Phycocyanin is a protein-chromophore structure present in Arthrospira platensis commonly used as a blue-colorant in food. Color losses of phycocyanin can be reduced by electrostatic complexation with λ-carrageenan. The aim of this study was to investigate the effect of molecular weight (MW) of λ-carrageenan on the color stabilization of electrostatic complexes formed with phycocyanin and λ-carrageenan. Samples were heated to 70 or 90°C at pH 3.0 and stored at 25°C for 14 days. The MW of λ-carrageenan was reduced by ultrasound treatments for 15, 30, 60, and 90 min. Prolonged ultrasonication had a pronounced effect on the Mw, which decreased from 2,341 to 228 kDa (0–90 min). Complexes prepared with low MW λ-carrageenan showed greater color changes compared to complexes prepared with high MW λ-carrageenan. The MW had no visible effect on color stability on day 0, but green/yellow shifts were observed during storage and after heating to 70°C. Medium MW showed less color stabilization effects compared to low MW when heated to 70°C. Moreover, for solutions prepared with ultrasonicated λ-carrageenan, significant hue shifts toward green/yellow, and precipitation were observed after a heat treatment at 90°C. In addition, the sizes of the complexes were significantly reduced (646–102 nm) by using ultrasonicated λ-carrageenan, except for the lowest MW λ-carrageenan when heated to 90°C. Overall, these findings demonstrated that decreasing the MW of λC had adverse effects on the color stability of PC:λC complexes heated to 70 and 90°C.

Effects of Saignée and Bentonite Treatment on Phenolic Compounds of Marquette Red Wines.

To improve the phenolic extraction and color stability of red wine made from cold-hardy grapes, two winemaking practices, saignée and bentonite, were applied separately and in combination on Marquette grapes at crushing. The effects of these winemaking strategies on Marquette wine’s basic chemical properties, monomeric and polymeric phenolic compounds were studied, as well as the development of color characteristics from crushing to 5 months of aging. The saignée (9% juice run-off) treatment showed little impact on the phenolic content of the finished wine, but showed an increase in color intensity. A hue shift towards an orange-yellow tone was observed in the bentonite-treated wines, which was associated with a loss of monomeric anthocyanins. The combination of saignée and bentonite showed less impact on removing anthocyanins and wine color, and increased phenolics content, therefore improving the extraction of non-anthocyanins monomeric phenolics. Although this combination treatment led to the highest concentration of tannin content after pressing, this difference between the control and other treatments disappeared over time. These results suggested that the interactions between tannins and other wine compounds still occur after removing proteins in Marquette wines.

Sensitivity examination of YOLOv4 regarding test image distortion and training dataset attribute for apple flower bud classification

ABSTRACT Applications of convolutional neural network (CNN)-based object detectors in agriculture have been a popular research topic in recent years. However, complicated agricultural environments bring many difficulties for ground truth annotation as well as potential uncertainties for image data quality. Using YOLOv4 as a representation of state-of-the-art object detectors, this study quantified YOLOv4’s sensitivity against artificial image distortions including white noise, motion blur, hue shift, saturation change, and intensity change, and examined the importance of various training dataset attributes based on model classification accuracies, including dataset size, label quality, negative sample presence, image sequence, and image distortion levels. The YOLOv4 model trained and validated on the original datasets failed at 31.91% white noise, 22.05-pixel motion blur, 77.38° hue clockwise shift, 64.81° hue counterclockwise shift, 89.98% saturation decrease, 895.35% saturation increase, 79.80% intensity decrease, and 162.71% intensity increase with 30% mean average precisions (mAPs) for four apple flower bud growth stages. The performance of YOLOv4 decreased with both declining training dataset size and training image label quality. Negative samples and training image sequence did not make a substantial difference in model performance. Incorporating distorted images during training improved the classification accuracies of YOLOv4 models on noisy test datasets by 13 to 390%. In the context of apple flower bud growth-stage classification, except for motion blur, YOLOv4 is sufficiently robust for potential image distortions by white noise, hue shift, saturation change, and intensity change in real life. Training image label quality and training instance number are more important factors than training dataset size. Exposing models to test-image-alike training images is crucial for optimal model classification accuracies. The study enhances understanding of implementing object detectors in agricultural research.

Effects of inter-reflections on the chromatic structure of the light field

Chromatic properties of the effective light in a space are hard to predict, measure and visualise. This is due to complex interactions between materials and illuminants. Here, we describe, measure and visualise the effects of inter-reflections on the structure of the physical light field for diffusely scattering scenes. The spectral properties of inter-reflections vary as a function of the number of bounces they went through. Via a computational model, these spectral variations were found to be systematic and correspond with brightness, saturation and hue shifts. We extended our light-field methods to measure and understand these spectral effects on the first-order properties of light fields, the light density and light vector. We tested the model via a set of computer renderings and cubic spectral illuminance measurements in mock-up rooms under different furnishing scenarios for two types of illuminants. The predicted spectral variations were confirmed and indeed varied systematically within the resulting light field, spatially and directionally. Inter-reflections predominantly affect the light density spectrum and have less impact on the light vector spectrum. It is important to consider these differential effects for their consequences on the colour rendering of 3-dimensional objects and people.

Hue-preserving image enhancement via complementary enhancing terms

Hue-preserving image enhancement is a very challenging and important research topic in image/video processing and computer vision fields. In the past decades, spectral methods, histogram-based methods, and spatial methods are proposed to partially tackle this problem. However, most of them still suffer from the challenges in enhancing color images while preventing hue shift. In this paper, we build two complementary terms in a variational framework for enhancing images: one is for increasing the image brightness, and the other is for strengthening the edge structure. The two enhancing terms are adaptively united to enhance color images and preserve the original hue simultaneously. The existence and uniqueness of minimizer for the proposed variational model are rigorously established. An efficient numerical implementation of our model is also accomplished via the popular split Bregman method. A number of numerical experiments and comparisons with some state-of-the-art methods are conducted to demonstrate the good performance of the newly proposed model.

Contributed Session III: Disentangling object color from illuminant color: The role of color shifts

Research has shown that disentangling surface and illuminant colors was possible based on various scene statistics. This study investigates the statistical cues induced by the chromatic effects of interreflections. We present a numerical analysis of ambiguous spectral pairs, in which the spectral power distribution of the illuminant in one scene matched the surface reflectance function in the other scene and vice versa. If the scenes are flat or convex and perfectly matte (Lambertian), the reflected light spectra of both cases are identical. However, the incident light undergoes interreflections for concave scenes. The spectral power of interreflections will be absorbed spectrally in an exponential way, dependent on the number of interreflections. We found that this causes systematic shifts towards the spectral reflectance peaks, resulting in brightness, saturation and hue shifts. Those paired cases' color differences (CIEDE2000) are so large that humans would be able to observe them if viewed simultaneously. In addition, we find that the color shifts cause qualitatively different gradients for chromatic materials and achromatic light and vice versa. Further psychophysical testing is necessary to see whether the different color shifts for the two cases can be recognized in isolation due to material or light properties. Moreover, the light densities and light vectors are spectrally different for these cases, creating different appearances of 3D objects in non-empty rooms.

Effect of hue shift towards robustness of convolutional neural networks

Computer vision systems become deployed in diverse real time systems hence robustness is a major area of concern. As a vast majority of the AI enabled systems are based on convolutional neural networks based models which use 3-channel RGB images as input. It has been shown that the performance of AI systems, such as those used in classification, is impacted by distortions in the images. To date most work has been carried out on distortions such as noise, blur, compression. However, color related changes to images could also impact the performance. Therefore, the goal of this paper is to study the robustness of these models under different hue shifts.