Green Color Values Research Articles

A Computer-Vision-Based Approach for Nitrogen Content Estimation in Plant Leaves

Nitrogen is an essential nutrient element required for optimum crop growth and yield. If a specific amount of nitrogen is not applied to crops, their yield is affected. Estimation of nitrogen level in crops is momentous to decide the nitrogen fertilization in crops. The amount of nitrogen in crops is measured through different techniques, including visual inspection of leaf color and texture and by laboratory analysis of plant leaves. Laboratory analysis-based techniques are more accurate than visual inspection, but they are costly, time-consuming, and require skilled laboratorian and precise equipment. Therefore, computer-based systems are required to estimate the amount of nitrogen in field crops. In this paper, a computer vision-based solution is introduced to solve this problem as well as to help farmers by providing an easier, cheaper, and faster approach for measuring nitrogen deficiency in crops. The system takes an image of the crop leaf as input and estimates the amount of nitrogen in it. The image is captured by placing the leaf on a specially designed slate that contains the reference green and yellow colors for that crop. The proposed algorithm automatically extracts the leaf from the image and computes its color similarity with the reference colors. In particular, we define a green color value (GCV) index from this analysis, which serves as a nitrogen indicator. We also present an evaluation of different color distance models to find a model able to accurately capture the color differences. The performance of the proposed system is evaluated on a Spinacia oleracea dataset. The results of the proposed system and laboratory analysis are highly correlated, which shows the effectiveness of the proposed system.

Color stability of computer aided design and computer aided manufacture composite ceramic/resin cements after accelerated ageing

Objective: To investigate the color stability of computer aided design and computer aided manufacture (CAD/CAM) composite ceramic/resin cements after accelerated ageing. Methods: Twelve groups (ten samples each group) were used as experimental groups, which were composed of CAD/CAM composite ceramic of three kinds of thickness (0.50, 0.75, 1.00 mm) (Lava Ultimate) associated with resin cements (Variolink N) of four colors (A1, A3, T, BL1). Another three groups of CAD/CAM composite ceramic/resin cements of three different kinds of thickness (0.50, 0.75, 1.00 mm) were used as control groups (ten samples each group). All samples were put into the xenon lamp ageing instrument to implement accelerated ageing. Spectrophotometers were used to measure the lightness (L(*)), red green color value (a(*)) and blue yellow color value (b(*)) of all samples before and after accelerated ageing process, and the changes of color variation (ΔE) was calculated. The effect of composite ceramic thickness and resin cement color on the changes of color variation (ΔE) before and after the ageing of CAD/CAM composite ceramic/resin cement and whether there was an interaction between them were tested by two-way ANOVA. Results: Before and after accelerated ageing, the ΔE of CAD/CAM composite ceramic/resin cements were <3.3. Two-way ANOVA showed that the thickness of CAD/CAM composite ceramics had an effect on ΔE (F=27.025, P<0.001), and the color of resin cement also had an effect on ΔE (F=15.606, P<0.001), but there was no interaction between them (F=0.534, P=0.829). Conclusions: The thickness of CAD/CAM composite ceramics and the color of resin cements could both affect the color stability of composite ceramic/resin cements combination. However, the resulted color change is within the clinically acceptable range.

Application of copper(II) oxide of electrocoagulation products of electroplating waste water as ceramic glaze dyes

This study aims to determine the effect of combustion temperatures and copper(II) oxide concentrations on ceramic glaze color. Electrocoagulation process was carried out using optimum conditions: pH 8, electrocoagulation time of 120 minutes, Al-Fe electrodes, and current density of 1.25 mA/cm2. Experiment variables include combustion temperatures (999, 1060, 1101 °C) and copper(II) oxide concentrations (0.88; 1.76, 2.64, 3.53% ). The results of the coagulant characterization with XRF showed copper(II) content of (22.04 ± 0.73)%. Besides that it also contains of other metals such as Cr, Cd, and Pb however below the detection limit. Coagulant is a metal hydroxide which is dried and calcined formed the oxide. Then, it was applied as a glaze ceramic dye. Based on the analysis of homogeneity using chromameter, the brightness value (L*) increased at the combustion temperature of 999 and 1060 °C, but at a temperature of 1101 °C it decreased. The green color value (a*) decreases when the combustion temperature is raised but the yellow value (b*) increased. When the metal oxide concentration was increased, L* and a* values decreased. While the b* value increased at a concentration of 0.88 to 1.76%, but at a concentration of 2.64 to 3.53% decreased.

Color stability of ceromer of different thicknesses and resin adhesive materials of different types after accelerated aging

This study aims to investigate the color stability of ceromer with different thicknesses and different types of resin adhesive materials after accelerated aging and provide references for clinical application and selections. Nine groups of experimental samples were used, and each group contained five samples. We made joint samples with ceromer having three different thicknesses (1.00, 0.75, 0.50 mm) combined with three different resin adhesive materials (RelyX Veneer, RelyX Unicem, Filtek Z350 Flow), respectively. All samples were placed into Xenon Lamp Aging Instrument to implement accelerated aging. Spectrophotometer was used to measure the lightness (L*), red green color value (a*), and blue yellow color value (b*) of all samples before and after accelerated aging. The change of lightness (ΔL), red green color value (Δa), blue yellow color value (Δb), and color variation (ΔE) were also calculated. We investigated the influence of ceromer veneer thicknesses and resin adhesive material types on color variation by two-factor analysis of variance. The thickness and type factors showed significant influence on ΔE values, and exhibited interactions (P < 0.05). The ΔE values of all experimental groups were lower than 3.3. After the accelerated aging process, all L*, a*, and b* values of the experimental groups decreased and the ΔL values were lower than 2.0. Ceromer veneer thickness and resin adhesive material types could affect the color stability of ceromer veneer and resin adhesive materials. The changes in lightness and color in ceromer veneer and resin adhesive materials are considered clinically acceptable after accelerated aging.

Development of variable rate sprayer for oil palm plantation

Development of variable rate sprayer for oil palm plantationThis project describes the design and development of a camera vision with color detection for the variable rate technology (VRT) automated sprayer. In this project, the smart sprayer system was already developed and mounted on the ATV. The automated sprayer system was developed by combination of the electromechanical system, PC parallel port relay board, the controller and visual basic programming software. This smart sprayer system is guided with the camera to detect the presence of weeds. Detection of weeds is based on the green color value from RGB value. The amount or percentage (%) of weeds detected determines the rate of spraying that is controlled by an electric motor and the relay board. In this project, the spray nozzles were modified to be fully open, fully closed and half open. The closing and opening of valves were controlled by the electromechanical system that receives the instruction from the camera vision. Experiments carried out shows that the nozzle is closed when the percentage of weeds detected is less than 2%. It is half open at 3% to 50% and fully open at more than 51%. The application rate of spraying can be determined from the result of the spraying operation.

Diagnostic Value of Quantitative EUS Elastography for Malignant Pancreatic Tumors: Relationship with Pancreatic Fibrosis

EUS elastography has been used to facilitate the diagnosis of pancreatic cancer, but as yet the interpretation of this procedure has been largely subjective. The present study has been designed to validate a quantitative approach for the analysis of EUS elastography, and to assess its relationship with pancreatic fibrosis. 86 patients with malignant pancreatic masses and 28 control subjects without any evidence of pancreatic diseases were examined by EUS elastography. EUS video sequences were subjected to a quantitative analysis based on mean hue histogram analysis. Pancreatic fibrosis was determined by quantitative morphometry in tissue specimens from 36 patients. The mean RGB (red, green, blue) value was significantly higher in the cancer patients compared to the controls (14.0±0.4 vs. 11.5±0.9; p=0.0085), albeit with significant overlap between the groups. In contrast, a much sharper separation between the groups was obtained based on the individual color values for blue, green and red (p<0.0001, respectively). By these means, 100% sensitivity and specificity for the distinction between tumor and normal tissue was obtained for the blue color value, while the red and green color values were less discriminative. The fractional fiber content of the tumors was unrelated to the respective hue histogram color values. Quantitative EUS elastography allows for clear differentiation between malignant pancreatic tumors and normal tissue. Using this approach, we demonstrated that the stiffness of pancreatic tumors is largely independent of their fiber content.

Digital image analysis and chlorophyll metering for phenotyping the effects of nodulation in soybean

Leaf photosynthesis and rhizobial nitrogen fixation are the two metabolic processes of utmost importance to legume growth and development. As these processes are closely related to each other, measuring of leaf chlorophyll content can provide information on the nodulation and nitrogen fixation status of crop plants. In the present investigation, a number of soybean breeding lines consisting of near-isogenic families which are genetically segregating for the nodulation trait were utilized in field experiments carried out across three growing seasons at Vienna, Austria. For phenotyping leaf chlorophyll content, the Minolta SPAD spectrometer was applied in parallel to a simple leaf digital image analysis procedure based on a commercial digital still camera. The main objectives of the research included the comparison of SPAD metering and image analysis for determination of chlorophyll content, phenotyping of the soybean nodulation vs. non-nodulation characteristic with respect to leaf, agronomic and seed traits, and relating both chlorophyll and image analysis data to seed quality characteristics. Nodulating and non-nodulating soybean lines significantly differed in chlorophyll content from the V5 (five leaves fully developed) soybean developmental stage onwards. Apart from chlorophyll content, leaf size, plant height, number of pods per plant, 1000-seed weight, and seed protein and oil content were also affected by nodulation type. The chlorophyll content of soybean leaves as determined by SPAD metering was significantly correlated ( r = −0.937) to the green color value (RGB color model) of leaf image analysis at the R3 (beginning of pod growth) soybean developmental stage. Both chlorophyll content and leaf image analysis parameters were correlated to 1000-seed weight, seed protein and seed oil content. Thus, it appears that these leaf parameters related to photosynthesis and nitrogen fixation could be utilized to determine the nitrogen status of a soybean crop and subsequently in forecasting seed quality parameters of the harvest product.

Effective soft-decision demosaicking using directional filtering and embedded artifact refinement

Demosaicking is an interpolation process that transforms a color filter array (CFA) image into a full-color image in a single-sensor imaging pipeline. In all demosaicking techniques, the interpolation of the green components plays a central role in dictating the visual quality of reconstructed images because green light is of maximum sensitivity in the human visual system. Guided by this point, we propose a new soft-decision demosaicking algorithm using directional filtering and embedded artifact refinement. The novelty of this approach is twofold. First, we lift the constraint of the Bayer CFA that results in the absence of diagonal neighboring green color values for directionally recovering diagonal edges. The developed directional interpolation method is fairly robust in dealing with the four edge features, namely, vertical, horizontal, 45-deg diagonal, and 135-deg diagonal. In addition, the proposed embedded refinement scheme provides an efficient way for soft-decision-based algorithms to achieve improved results with fewer computations. We have compared this new approach to six state-of-the-art methods, and it can outstandingly preserve more edge details and handle fine textures well, without requiring a high computational cost.

Numerical analysis of endoscopic autofluorescence imaging for cancerous tissue detection

This paper presents an application of numerical analysis to autofluorescence imaging for pathological tissue (mainly cancerous) tissue detection. The analysis was carried out using an application created in MathWorks Matlab. Autofluorescence images produced under ultraviolet illumination whose source was a xenon lamp or a semiconductor laser were subjected to processing. Classifying functions were designed and implemented on the basis of information about discrete red and green color values. The suitability of statistical analysis algorithms for the precise determination of areas corresponding to cancerous lesions at different stages of the disease is demonstrated. The classifying functions were also used in the real-time analysis of images obtained from conventional white-light endoscopy.

Effect of Several Controlled-Release Fertilizers on the Growth of Four Foliage Plants

Five types of controlled-release fertilizers were evaluated in individual experiments on Dieffenbachia amoena Bull., Philodendron scandens subsp. oxycardium Shott. Bunt. and Ficus benjamina L. Precise 12.0N-2.6P-5.0K (12-6-6) an encapsulated liquid fertilizer, applied at 656 kg (569 lb/A) N per ha per year, produced similar Dieffenbachia and Philodendron plant dry weights as 5 impregnated vermiculite and one ureaformaldehyde applied at higher rates of N. In a comparison with a water soluble 20.0N-8.7P-6.6K (20-20-20) fertilizer on Brassaia actinophylla Endl., dry weights and foliage color ratings of Brassaia plants fertilized with the water soluble fertilizer were greater than those of plants receiving the controlled release fertilizers. Ficus height, visual rating, dry weight and differences in green color values of leaves of plants fertilized with Precise 12.0N-2.6P-5.0K (12-6-6) were greater than those receiving other controlled-release fertilizer treatments. In a second experiment, Ficus plants fertilized with high rates of several controlled-release fertilizers and Scott Pro-Grow 25.0N-2.2P-8.2K (25-10-10) rates were equal or better in growth than plants receiving Precise and Osmocote 14.0N-6.1P-ll.6K (14-14-14). Mag Amp 7.ON-I7.4P-4.1K (7-40-6) plants treated with 900 kg/ha (784 Ib/A) and 1200 kg/ha (1045 lb/A) performed poorly in all growth parameters measured. Plant growth from high rates of controlled-release fertilizers surface applied at the beginning of the experiment was equal to that produced with 20.0N-8.7P-16.6K (20-20-20) soluble fertilizer applied weekly at the rate of 1582 kg N/ha (1477 lb/A) per year.