scholarly journals Backward Spectral Characterization of Liquid Crystal Display Based on Forward Spectral Characterization

2016 ◽  
Vol 2016 ◽  
pp. 1-8
Author(s):  
Jian-qing Zhang ◽  
Fang Cai ◽  
Xiao-ying Shen ◽  
Zhen Liu ◽  
Ming Zhu
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystal Display ◽  
Color Space ◽  
Spectral Characterization ◽  
Spectral Radiation ◽  
Digital Input ◽  
Space Transformation ◽  
Color Space Transformation ◽  
Characterization Model ◽  
The Difference

A backward spectral characterization for Liquid Crystal Display by the use of rule for the maximum peak of spectral radiation curves changing with the digital input values is proposed; this new model is developed based on forward spectral characterization. It deals with estimation ofRGBused as input to the digital display from known spectral radiation curves. We first investigate the rule for the peak of spectral radiation curves changing with the digital input values of primaries; then the initial digital inputRGBare calculated based on that rule using the known spectral radiation curvesρ0. Third,RGBare inputted into forward spectral characterization model and the corresponding spectral radiation curvesρ1are predicted. Last,RGBare modified according to the difference between predictedρ1and knownρ0, until this difference satisfied the prediction accuracy of the inverse characterization model. The inverse model has the advantage of using the same model for both forward and inverse color space transformation. This improves the accuracy of the color space transformation and reduces the source of errors. Results for 3 devices are shown and discussed; the accuracy of this model is considered sufficient for many applications.

Color Space Transformation using Neural Networks

2019 ◽  
Vol 2019 (1) ◽  
pp. 153-158
Author(s):  
Lindsay MacDonald
Keyword(s):  
Neural Network ◽  
Neural Networks ◽  
Color Space ◽  
Reflectance Spectra ◽  
Network Architectures ◽  
Color Spaces ◽  
Natural Materials ◽  
Space Transformation ◽  
Color Space Transformation

We investigated how well a multilayer neural network could implement the mapping between two trichromatic color spaces, specifically from camera R,G,B to tristimulus X,Y,Z. For training the network, a set of 800,000 synthetic reflectance spectra was generated. For testing the network, a set of 8,714 real reflectance spectra was collated from instrumental measurements on textiles, paints and natural materials. Various network architectures were tested, with both linear and sigmoidal activations. Results show that over 85% of all test samples had color errors of less than 1.0 ΔE2000 units, much more accurate than could be achieved by regression.

A Correspondence-Free Color Chart Design for Color Calibration

2020 ◽  
Vol 2020 (1) ◽  
pp. 100-104
Author(s):  
Hakki Can Karaimer ◽  
Rang Nguyen
Keyword(s):  
Color Space ◽  
Fixed Number ◽  
New Approach ◽  
Color Chart ◽  
Color Calibration ◽  
Space Transformation ◽  
Color Space Transformation ◽  
Chart Design ◽  
Calibration Approach

Colorimetric calibration computes the necessary color space transformation to map a camera's device-specific color space to a device-independent perceptual color space. Color calibration is most commonly performed by imaging a color rendition chart with a fixed number of color patches with known colorimetric values (e. g., CIE XYZ values). The color space transformation is estimated based on the correspondences between the camera's image and the chart's colors. We present a new approach to colorimetric calibration that does not require explicit color correspondences. Our approach computes a color space transformation by aligning the color distributions of the captured image to the known distribution of a calibration chart containing thousands of colors. We show that a histogram-based colorimetric calibration approach provides results that are onpar with the traditional patch-based method without the need to establish correspondences.

Spectral radiance backward characterization model for liquid crystal display based on key wavelengths

2021 ◽  
Vol 18 (6) ◽  
pp. 065701
Author(s):  
Xiangcai Ma ◽  
Dawei Zhang ◽  
Jiqing Lian ◽  
Xiaohong Wang
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystal Display ◽  
Spectral Radiance ◽  
Characterization Model

A Novel Piece-Wise Linear Algorithm for Human Skin Segmentation

2015 ◽  
Vol 743 ◽  
pp. 317-320
Author(s):  
Ravi Subban ◽  
Pasupathi Perumalsamy ◽  
G. Annalakshmi
Keyword(s):  
Skin Color ◽  
Color Space ◽  
Skin Detection ◽  
Color Spaces ◽  
Color Component ◽  
Skin Segmentation ◽  
Space Transformation ◽  
Color Space Transformation ◽  
Comprehensive Knowledge ◽  
Novel Method

This paper presents a novel method for skin segmentation in color images using piece-wise linear bound skin detection. Various color schemes are investigated and evaluated to find the effect of color space transformation over the skin detection performance. The comprehensive knowledge about the various color spaces helps in skin color modeling evaluation. The absence of the luminance component increases performance, which also supports in finding the appropriate color space for skin detection. The single color component produces the better performance than combined color component and reduces computational complexity.

Hygromechanical Analysis of Liquid Crystal Display Panels

2013 ◽  
Vol 135 (4) ◽  
Author(s):  
Toru Ikeda ◽  
Tomonori Mizutani ◽  
Kiyoshi Miyake ◽  
Noriyuki Miyazaki
Keyword(s):  
Boundary Layer ◽  
Liquid Crystal ◽  
Numerical Analysis ◽  
Diffusion Coefficients ◽  
Liquid Crystal Display ◽  
Fem Analysis ◽  
Contact Condition ◽  
Henry's Law ◽  
Henry’S Law ◽  
The Difference

Liquid crystal displays (LCDs) are getting larger, and the homogeneity of an LCD panel is becoming very important for the quality of the display. Inhomogeneity in an LCD panel can be caused by inhomogeneity of its materials and the defective production process, warpage of the panel due to changes in the temperature and humidity, and so on. In this study, we developed a scheme of hygromechanical analysis to reduce the warpage of an LCD. First, we measured the diffusion coefficients and Henry's law coefficients of the respective components of an LCD using a thermogravimetric analyzer (TGA) under controlled humidity. We then measured the coefficients of moisture expansion (CME) of the components using a humidity-controlled thermomechanical analyzer (TMA). We analyzed the hygromechanical deformations of the respective components, a polarizing plate and an LCD panel using the finite element method (FEM) with measured diffusion coefficients, Henry's law coefficients and the CMEs of the respective components. The analyzed deformations of the respective components corresponded quantitatively with the deformations measured experimentally. However, the analyzed deformation of the polarizing plate did not correspond with the measured deformation perfectly. A polarizing plate is made by sandwiching a polarizer between two sheets of protection film. We ignored the effect of the thin boundary layer between the polarizer and its protecting film in this analysis, and the effect of this boundary layer on the diffusion of moisture may have caused the difference between the analysis and the measurement. The expected warpage of the analyzed LCD corresponded qualitatively with the measured warpage. However, the numerical analyzed strains near the edge of the LCD panel strongly shifted to the compression side compared to the experimental measured strains. A possible reason for this shift was the difference in the boundary condition at the edge of the LCD panel between the numerical analysis and the experimental measurement. The actual edge of the LCD panel was fastened by a bezel, and the contact condition between the LCD panel and the bezel was ambiguous. To perform a quantitative analysis, we will need to investigate the contact condition between the LCD panel and the bezel and introduce it to the numerical analysis. This is left for a future study. We qualitatively investigated the warpage of LCDs with two types of protecting film and different directions of polarizing plates using the developed technique of FEM analysis.

scholarly journals Color Edge Detection Based on the Fusion of Intensity and Chromatic Differences

2020 ◽  
Vol 8 (6) ◽  
pp. 1038-1041
Keyword(s):  
Edge Detection ◽  
Color Space ◽  
Mathematical Methods ◽  
Image Intensity ◽  
Space Transformation ◽  
Color Space Transformation ◽  
Intensity Information

Edge detection is the name for a set of mathematical methods which target at classifying points in an image at which the image intensity varies sharply or, has discontinuities. The paper tries to find the solution for detecting color edges based on color and intensity information of two new images H-image and T-image crafted on color space transformation, that will produce two-resulted edges derivates of H-image and T-image and are at last coalesced to obtain final edge.

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