Red Green Blue Pixel Research Articles

A Polyvinyl Alcohol-Based Thermochromic Material for Ultrasound Therapy Phantoms

Temperature estimation is a fundamental step in assessment of the efficacy of thermal therapy. A thermochromic material sensitive within the temperature range 52.5°C–75°C has been developed. The material is based on polyvinyl alcohol cryogel with the addition of a commercial thermochromic ink. It is simple to manufacture, low cost, non-toxic and versatile. The thermal response of the material was evaluated using multiple methods, including immersion in a temperature-controlled water bath, a temperature-controlled heated needle and high-intensity focused ultrasound (HIFU) sonication. Changes in colour were evaluated using both RGB (red, green, blue) maps and pixel intensities. Acoustic and thermal properties of the material were measured. Thermo-acoustic simulations were run with an open-source software, and results were compared with the HIFU experiments, showing good agreement. The material has good potential for the development of ultrasound therapy phantoms.

Full-color micro-LED display with high color stability using semipolar (20-21) InGaN LEDs and quantum-dot photoresist

Red-green-blue (RGB) full-color micro light-emitting diodes (μ-LEDs) fabricated from semipolar (20-21) wafers, with a quantum-dot photoresist color-conversion layer, were demonstrated. The semipolar (20-21) InGaN/GaN μ-LEDs were fabricated on large (4 in.) patterned sapphire substrates by orientation-controlled epitaxy. The semipolar μ-LEDs showed a 3.2 nm peak wavelength shift and a 14.7% efficiency droop under 200 A / cm 2 injected current density, indicating significant amelioration of the quantum-confined Stark effect. Because of the semipolar μ-LEDs’ emission-wavelength stability, the RGB pixel showed little color shift with current density and achieved a wide color gamut (114.4% NTSC space and 85.4% Rec. 2020).

Multi-colour light emission based on pixel-array phosphor layer in LEDs

Phosphor layers are of vital importance for the development of advanced phosphor-converted light-emitting diodes (LEDs). However, owing to the fixed ratio of red-green-blue (RGB) phosphors, it has been difficult for the RGB phosphor layers with conventional structure to tune light emission colours. Herein, we have experimentally fabricated nine types of phosphor layers with patterned RGB pixel array, which consist of tuneable RGB ratio in a planar configuration. Moreover, we carried out optical simulation based on Monte-Carlo theory to assist in adjusting the light-emission colours and the corresponding chromaticity coordinates. The simulations were further verified by the experimental results via samples fabricated by the stencil printing technique. In accordance with the nine types of phosphor layers with patterned pixel arrays in various RGB ratios, we have finally obtained corresponding nine light-emission colours for the applications of LED light emission decoration. These designed advanced pixel-array phosphor layers demonstrate great potential for applications in decorated light emission and display devices with significant implications for industrial improvement in these research areas.

Image-Based Quantitative Analysis of Foxing Stains on Old Printed Paper Documents

We studied the feasibility of image-based quantitative analysis of foxing stains on collections of old (16th–20th century) European books stored in the Rare Book Library of the Seoul National University in Korea. We were able to quantitatively determine the foxing affected areas on books from their photographs using a newly developed image processing software (PicMan) including cultural property characterization applications, specifically. Dimensional and color analysis of photographs were successfully done quantitatively. Histograms of RGB (red, green, blue) pixels of photographs clearly showed the change in color distribution of foxing stains compared to the other areas of the photographs. Several sample images of quantitative measurement of foxing stains and virtually restored images were generated to provide easy visual inspection and comparison between restored images and the original photographs. Image quality, resolution, and digital file format requirements for quantitative analysis are described. Image-based quantitative analysis of foxing stains on paper documents are found to be very promising towards automation for objective characterization of photographs of cultural properties. This technique can be used to create a cultural property digital database. Quantitative and statistical analysis techniques can be introduced to monitor the effect of storage and conservation environment on the cultural properties.

Multi-photoactive quantum-dot channels for zinc oxide phototransistors by a surface-engineering patterning process

Red, green, blue (RGB) selective zinc oxide (ZnO) phototransistors with multi-photoactive quantum-dot (QD) channels have been fabricated by a charge-assisted layer-by-layer (LbL) patterning process. QDs were patterned as RGB pixels in multi-photoactive QD channels through the LbL process. The solution-processed ZnO film, which acts as an active-channel layer of the ZnO TFTs, is patterned via a photoinduced surface engineering method to reduce the leakage current of the ZnO TFTs. The average off-current of the patterned ZnO TFTs reduced from 10−10 to 10−11 A. QDs absorb visible light and generate photoelectrons, which are then transferred to the ZnO to produce photocurrents. The device shows photoresponsivity of 9.4 mA/W, 12.5, and 137 A/W to the illumination of 638, 520, and 405 nm wavelength light. Our results suggest a promising way to develop an RGB selective phototransistor that uses QDs as a visible light absorption layer and ZnO as an active channel semiconductor.

Single-Sensor RGB-NIR Imaging: High-Quality System Design and Prototype Implementation

In recent years, many applications using a set of red-green-blue (RGB) and near-infrared (NIR) images, also called an RGB-NIR image, have been proposed. However, RGB-NIR imaging, i.e., simultaneous acquisition of RGB and NIR images, is still a laborious task because existing acquisition systems typically require two sensors or shots. In contrast, single-sensor RGB-NIR imaging using an RGB-NIR sensor, which is composed of a mosaic of RGB and NIR pixels, provides a practical and low-cost way of one-shot RGB-NIR image acquisition. In this paper, we investigate high-quality system designs for single-sensor RGB-NIR imaging. We first present a system evaluation framework using a new hyperspectral image data set we constructed. Different from existing work, our framework takes both the RGB-NIR sensor characteristics and the RGB-NIR imaging pipeline into account. Based on the evaluation framework, we then design each imaging factor that affects the RGB-NIR imaging quality and propose the best-performed system design. We finally present the configuration of our developed prototype RGB-NIR camera, which was implemented based on the best system design, and demonstrate several potential applications using the prototype.

Swingle citrumelo seed vigor and storability associated with fruit maturity classes based on RGB parameters

Citrus seeds normally have low storability. Identifying an optimal fruit harvest time for production of high vigor seeds is important for nurseries; however, identifying this stage for Swingle citrumelo fruits has been based only on visual color examination, and research related to this parameter has been inconsistent. The main objective of this study was to evaluate a red-green-blue (RGB) color measurement system for successful identification of Swingle citrumelo fruits possessing seeds with maximum physiological potential and storability. Fruits were harvested at three ripening stages identified as green (G), greenish-yellow (GY), and yellow (Y) pericarp, photographed, and the images processed using ImageJ software. Data were expressed as the average pixel value of R, G and B color components and a mean RGB pixel value (R+G+B/3). After harvest, seeds were evaluated for water content, germination, seedling emergence, length, dry mass and vigor as measured by the Seed Vigor Imaging System - SVIS (uniformity and vigor indexes) after 0 and 5 months storage (5 °C and 65 % relative humidity). Percentage of ruptured coat seeds was also evaluated after extraction. The R color component provided the best identification of each G, GY and Y fruits. Seeds extracted from GY fruits had higher storage potential compared with seeds from G and Y fruits. Thus, precise fruit ripening classification can be generated using the RGB color system to identify the best time for harvest to obtain seeds with greater physiological and storage potential.

Imaging Evaluation for Simulated RGBW Color LCDs With the Proposed Color Conversion Algorithm

This paper is a comparative evaluation of imaging performance for two types of color liquid crystal displays (LCDs) with Quad RGBW (red, green, blue, and white) and Stripe RGB (red, green, blue) pixel units by means of simulation study. In accordance with the study results, using the proposed color conversion algorithm could achieve color consistence and higher luminance for rendering images with RGBW rather than RGB pixel units. Simultaneously, instrumental color measurement via a spectrometer was done which results also proved that almost same color values of rendering images with RGBW pixel units as well as those images with original RGB pixel units, and higher luminance was achieved. Finally, the pseudocolor phenomenon of rendering images with RGBW pixel units is analyzed and discussed on the basis of human vision model.

A Novel Steganographic System for Data Hiding in Video/Audio

The rapid development of technology made it easier to send the data accurate and faster to the destination. The most important factor of information technology and communication is the security of the information. This security can be achieved through steganography. Steganography is art and science of invisible communication. This paper mainly focuses on audio and video steganography. Video Steganography hides secret data within a video and audio steganography deals with hiding secret data within audio. The secret data is first compressed, encrypted and then embed into the cover frames in such a way that eight bits of the secret data are divided into 2, 2, 2, 2 and then embedded into the RGB (Red, Green, Blue) pixel values of the cover frames respectively and the remaining 2 bits are inserted in the next pixel of cover frame and so on. The proposed technique is compared with existing LSB (Least Significant Bit) based steganography and the results are found to be encouraging.

Non Conventional Approaches to Reflective Color Displays

ABSTRACT Emissive displays use additive color synthesis provided by two dimensional Red Green Blue pixels arrays; reflective displays would use the subtractive color synthesis from primary Cyan Magenta Yellow colors: several attempts show that photographic like structures using 3 active superposed color layers constitutes a very challenging objective. Beside the transflective mode compromise, most current attempts concern black and white or bicolor reflective displays, as well as reflective micro displays for image projectors. After reviewing these technologies, we consider some new approaches to reflective color displays, including the direct color synthesis using physical colors generation such as light dichroic reflection, diffraction and scattering.

Color Classifier for Symptomatic Soybean Seeds Using Image Processing.

Symptoms associated with fungal damage, viral diseases, and immature soybean (Glycine max) seeds were characterized using image processing techniques. A Red, Green, Blue (RGB) color feature-based multivariate decision model discriminated between asymptomatic and symptomatic seeds for inspection and grading. The color analysis showed distinct color differences between the asymptomatic and symptomatic seeds. A model comprising six color features including averages, minimums, and variances for RGB pixel values was developed for describing the seed symptoms. The color analysis showed that color alone did not adequately describe some of the differences among symptoms. Overall classification accuracy of 88% was achieved using a linear discriminant function with unequal priors for asymptomatic and symptomatic seeds with highest probability of occurrence. Individual classification accuracies were asymptomatic 97%, Alternaria spp. 30%, Cercospora spp. 83%, Fusarium spp. 62%, green immature seeds 91%, Phomopsis spp. 45%, soybean mosaic potyvirus (black) 81%, and soybean mosaic potyvirus (brown) 87%. The classifier performance was independent of the year the seed was sampled. The study was successful in developing a color classifier and a knowledge domain based on color for future development of intelligent automated grain grading systems.

Spectral Imaging through the light microscope: Application to the image analysis of colored structures in histology

Color is an important factor in defining structures in both biological and materials microscopy. Indeed, the field of histology/pathology is founded on the use of special dyes and staining procedures which label features of interest with a defining color. Of particular interest is the use of colorigenic substrates in enzyme linked – immunochemistry on tissue sections and the subsequent measurement of the amount of labeling in a given tissue. Typically, colored image objects such as the red deposit produced by the reaction of AEC (aminoethylcarbazole) substrate with peroxidase enzyme can be detected in RGB (red, green, blue) images by a combination of RGB pixel intensities or by HSI (hue, saturation, intensity) pixel intensities. Using a new color imaging system with spectral image acquisition capabilities, we have develop an imaging algorithm based on the absorption spectra of the colored object and the counter stained surrounding space that provides optimal images of segmentation and morphological measurement.The basic system consists of a low light level CCD coupled to a liquid crystal tunable filter (Cambridge Research Instruments). The filter is based on the Lyot-type birefringent filter and provides continuous wavelength selection from 400 - 720 nm with wavelength dependent resolution of about 10 nm at 500 nm. The system is controlled by a Silicon Graphic workstation and Isee software written by Inovision Corp. Spectral images, i.e., images at a given wavelength, can be obtained and the intensity of objects with in a given image can be sampled as a function of wavelength for microspectro -photometric or -fluorometric analysis.