The Experts below are selected from a list of 2079 Experts worldwide ranked by ideXlab platform
Ying Guo - One of the best experts on this subject based on the ideXlab platform.
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Effect of Different Standard Light Sources on the Red Color of Rhodochrosite
DEStech Transactions on Computer Science and Engineering, 2019Co-Authors: Rui-xing Zheng, Ying Guo, Yao Yao, Jia-yi GaoAbstract:Based on the Uniform Color Space CIE1976L*a*b* system, the Color of rhodochrosite is characterized by three elements: lightness L*, chroma C* and hue angle ho. On the basis of the Color analysis of rhodochrosite, the standard D65 light source, A light source and CWF light source were used as experimental light sources to explore the influence of different light sources on the three Color elements of rhodochrosite, and comprehensively analyze the influence of different light sources on rhodochrosite Color. The conclusion is that A light source can improve the L* value and C* value of rhodochrosite to make it more bright and brilliant, which is suitable as the display light source of rhodochrosite; and CWF is not suitable as the illumination light source of rhodochrosite.
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feasibility study on quality evaluation of jadeite jade Color green based on gemdialogue Color chip
Multimedia Tools and Applications, 2019Co-Authors: Ying Guo, Xiang ZongAbstract:The paper studied quality evaluation of Jadeite-jade Color green through GemDialogue. There are five green-related Color codes in GemDialogue, including G2Y, Y2G, G, B2G and G2B. After parametric analysis on three measured Color masks with different combinations, we clarified the Color change rules of different Color codes and zones superimposed by different Color masks. First of all, based on CIE 1976 L*a*b* Uniform Color Space system, the Color range of 728-piece Jadeite-jade Color green was determined: L*∈(5.64, 64.17), h0∈(125.21, 171.10), and C*∈(10.53, 85.89), namely conforming the appearance characteristics of Jadeite-jade Color green. Then, five green-related Color codes in GemDialogue Color chip system were selected to test the Color changes of 50 Color bands with combination of three Color masks in different superposition forms. The changes of Color hue, lightness and chroma between the Color codes and zones before and after combination were considered as the indicators. The results show that changes of hue angle for standard green Color codes is consistent with that of yellow Color codes, but opposite to that of blue Color codes. In the process changing from yellow to blue, the overall lightness moves from high to low values, in line with the sensory fact that naked eyes perceives higher lightness of yellow Color than that of the blue. The overall Color chroma of five Color bands significantly reduces with fading yellow hue and increasing blue hue.
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study on turquoise s green Color grading and quality evaluation of Color based on cie1976 l a b Uniform Color Space
DEStech Transactions on Materials Science and Engineering, 2017Co-Authors: Xueding Wang, Ying Guo, Xin Zhang, Yue Cui, Jun TangAbstract:Based on CIE1976 L * a * b * Uniform Color Space, we quantitatively measure d 52 pieces of green turquoise about L * , a * and b * under illuminant D65. These Colors were divided well into seven categories by Kmeans clustering analysis and the conseque n ce from ANOVA illustrated that there was evident difference among every category ’ s L * , a * and b * . By Fisher discriminant analysis to summarize the difference among various categories, every category ’ s L * , a * and b * were substituted into seven linear discriminant functions to verif y the accuracy of clustering. The accuracy was 98.1% and met requirement to turquoise green Color grading . Combing with naked eyes ’ observation, turquoise ’ s green Color was graded into seven levels for light and chroma, consisting of Fancy Vivid(FV), Fancy Intense(FI), Fancy Deep(FDe), Fancy(F), Fancy Dark(FDa), Fancy Light(FL), Light(L).
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quality evaluation of tourmaline red based on Uniform Color Space
Cluster Computing, 2017Co-Authors: Ying GuoAbstract:Based on the Uniform Color Space $$\hbox {CIE}\,1976\hbox {L}^{{*}}\hbox {a}^{{*}}\hbox {b}^{{*}},$$ the red Colors of 310 tourmalines were conducted with the research of Color Colorimetry. In terms of the quantitative analysis of Color indexes such as lightness, chroma and Color hue, we put forward the eight-class five-level systems for quality evaluation of tourmaline red by K-Means cluster analysis. The systems were sorted from superior to inferior: Fancy Vivid, Fancy Intense, Fancy Deep, Fancy and Fancy Dark. Through Fisher discriminant, the accuracy was proved to be up to 98.7%. Furthermore, we analyzed the effects of different standard light sources (D $$_{65},$$ A and CWF) on tourmaline red in detail. It was pointed out that D $$_{65}$$ could better reflect the Color of non-self-luminous object, which was suitable for quality evaluation of tourmaline red. Light source A significantly improved the chroma and hue of tourmaline red for red tourmaline display. Light source CWF reduced the chroma of tourmaline red, making the hue significantly deviated from the red. Therefore, CWF was not suitable for tourmaline red lighting. Finally, the work discussed the effects of non-Color background lightness and Color background on tourmaline red to derive the following results: (1) in the process of non-Color background lightness transformation, the lightness and chroma of tourmaline red were sensitive and changed significantly, with high synchronism; whereas, the Color hue has unobvious change. The higher lightness and chroma of tourmaline red led to larger effects of non-Color background lightness transformation to visual lightness and saturation. It was thus proved that the non-Color background was suitable for quality evaluation of tourmaline red. (2) In the process of Color background transformation, Color metal alloy background has significantly higher lightness (average lightness 83.81) and chroma (average chroma 39.21) than tourmaline red, with obvious orange hue (average hue angle 74.48). Therefore, Color metal alloy background significantly enhanced the lightness and chroma of tourmaline red, thus greatly contributing to quality evaluation of tourmaline red. However, Color metal alloy background made orange hue obvious, namely strengthening mixed hue of non-mainstream red, which was not conducive to quality evaluation of tourmaline red. Therefore, Color metal alloy background was only suitable for inlaid jewelry material or gemstone display rather than quality evaluation.
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metamerism appreciation of jadeite jade green under the standard light sources d65 a and cwf
Acta Geologica Sinica-english Edition, 2016Co-Authors: Ying Guo, Huan Wang, L I Xiang, Shirong DongAbstract:We tested 288 pieces of the polished cabochon jadeite-jade with high quality green and smooth surfaces using the Colorimeter Color i5 based on the CIE 1976 L*a*b* Uniform Color Space. The Color changes after alternating three CIE standard light sources D65, A and CWF were compared, and the degree of metamerism was evaluated. The results show that the CIE standard light sources D65, A and CWF increase the chroma of green and turn bluish green into vivid green, which are similar or to nearly Colorless and transparent glass-like samples with fine textures. When the three light sources were individually alternated, the lightness of the jadeite-jades showed little change, but the tone changed significantly. Metamerism occurred only in 3 pairs among the 16 samples that were selected by cluster analysis for quality, and the metamerism Colors were highly consistent of L*D65∊(43.47, 46.75), C*D65∊(65.20, 68.80) and ho*D65∊(138.10, 140.23). We can conclude that the jadeite-jade green gradually turns to blue when the Color temperature of the light source increases. But when considering both the light sources and the samples, D65 is more suitable to be the light source of jadeite-jade green when compared with the light sources CWF and A. Compared with the CIE standard green and high chroma green, high-quality jadeite-jade green has a slight yellow tone, low lightness and high chroma. The special metamerism index decreased to 1 when the light source alternated among D65, A and CWF. Therefore, the Color of jadeite-jade green might be slightly influenced by alternating of the light sources.
Ming Ronnier Luo - One of the best experts on this subject based on the ideXlab platform.
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performance comparison of Uniform Color Spaces by integrating into a tone mapping operator
2018Co-Authors: Muhammad Usman Khan, Muhammad Safdar, Muhammad Farhan Mughal, Ming Ronnier LuoAbstract:Typically, tone mapping operators are used to map luminance of high dynamic range (HDR) scenes to that of a displayable range. The goal of this study was to compare the performance of different Uniform Color Spaces (CIELAB, ICTCP, and Jazbz) by integrating them into a tone mapping operator. The Contrast Limited Adaptive Histogram Equalization-based Tone Mapping Operator (CLAHE-TMO) was used here. For this purpose, the HDR radiance map of a given scene was first constructed from multiple exposures of the scene captured by using an ordinary RGB camera. The radiance map was then transformed to a Uniform Color Space for the application of TMO on its lightness channel. A psychophysical experiment was conducted using pair comparison method to compare performance of different Uniform Color Spaces. Tone mapped images were compared in four different contexts: preference, naturalness, contrast, and texture details. The experimental results are reported here.
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perceptually Uniform Color Space for image signals including high dynamic range and wide gamut
Optics Express, 2017Co-Authors: Muhammad Safdar, Guihua Cui, Youn Jin Kim, Ming Ronnier LuoAbstract:A perceptually Uniform Color Space has been long desired for a wide range of imaging applications. Such a Color Space should be able to represent a Color pixel in three unique and independent attributes (lightness, chroma, and hue). Such a Space would be perceptually Uniform over a wide gamut, linear in iso-hue directions, and can predict both small and large Color differences as well as lightness in high dynamic range environments. It would also have minimum computational cost for real time or quasi-real time processing. Presently available Color Spaces are not able to achieve these goals satisfactorily and comprehensively. In this study, a Uniform Color Space is proposed and its performance in predicting a wide range of experimental data is presented in comparison with the other state of the art Color Spaces.
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a Uniform Color Space based upon ciecam97s
9th Congress of the International Colour Association, 2002Co-Authors: Ming Ronnier LuoAbstract:This paper describes a new Uniform Color Space which was derived by modifying CIECAM97s to fit available large Color difference datasets including CII-Zhu, OSA, Guan, BFDB- Textile, BFDB-Paint and Munsell. Testing results show that the new Color Space fit the above experimental datasets better than the current best CIELAB and IPT Spaces.
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llab model for Color appearance and Color difference evaluation
Color Imaging: Device-Independent Color Color Hard Copy and Graphic Arts, 1996Co-Authors: Ming Ronnier LuoAbstract:An ideal system of Colorimetry should provide measures agreeing to what we see in three respects: Color specification, difference and appearance. A successful method to quantify these measures depends upon the reliability of psychophysical experimental data. These data sets have been accumulated and were used to derive the LLAB model. The model includes two parts: a chromatic adaptation transform and a Uniform Color Space. Tristimulus values under a particular set of illuminant/observer conditions are transformed to those of D65/2 degree(s) conditions via a chromatic adaptation transform. A modified version of CIELAB is then used to calculate six perceived attributes: lightness (LL), redness-greenness (AL), yellowness-blueness (BL), Colorfulness (CL), hue angle (hL) and hue composition (HL). The model gives similar degree of prediction in comparison with the other state of the art models using the accumulated data sets. The LLAB model demonstrates that it is possible to achieve a system, which provides precise measures to quantify Color match, difference and appearance.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Yuncong Yang - One of the best experts on this subject based on the ideXlab platform.
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human facial complexion recognition of traditional chinese medicine based on Uniform Color Space
International Journal of Pattern Recognition and Artificial Intelligence, 2014Co-Authors: Li Zhuo, Jing Zhang, Yuncong Yang, Yan CaoAbstract:Face diagnosis of Traditional Chinese Medicine (TCM) is carried out by observing the human facial complexion to obtain the disease diagnostic results. The morbidity of the organs can be revealed by the human facial complexion, so the Color Space based on human visual system will be more conducive to facial complexion recognition. It is much suitable to measure and distinguish facial complexion by Uniform Lab Color Space, as it has the characteristic of isometry and high resolving power. First, the skin blocks in the human facial region are extracted by locating the eye position and mouth corner accurately. Second, the statistical characteristic of Color histogram and the characteristic of aberration chromatic in Lab Color Space are introduced to extract the facial complexion feature. At last, the support vector machine (SVM) is used to evaluate the performance of facial complexion recognition. The experimental results show the complexion feature proposed in this paper can achieve the better performance, with the facial complexion recognition rate up to 81%.
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Uniform Color Space based facial complexion recognition for Traditional Chinese Medicine
2014 13th International Conference on Control Automation Robotics & Vision (ICARCV), 2014Co-Authors: Jing Zhang, Chao Wang, Li Zhuo, Yuncong YangAbstract:Face diagnosis of Traditional Chinese Medicine (TCM) is carried out by observing the facial complexion to obtain the disease diagnostic results. Color Space based on human visual system will be more conducive to facial complexion recognition, which is more suitable to measure and distinguish facial complexion. Uniform Color Space based facial complexion recognition for TCM is proposed in this paper, which include: (1) the skin blocks in the human facial region are extracted by locating the eye position and mouth corner accurately; (2) the statistical characteristic of Color histogram and the characteristic of aberration chromatic in Lab Color Space are introduced to extract the facial complexion feature; (3) the support vector machine (SVM) is used to evaluate the performance of facial complexion recognition. The experimental results show the proposed complexion feature can achieve good performance, with the facial complexion recognition rate up to 81%.
Masahiko Yachida - One of the best experts on this subject based on the ideXlab platform.
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face detection from Color images using a fuzzy pattern matching method
IEEE Transactions on Pattern Analysis and Machine Intelligence, 1999Co-Authors: Haiyuan Wu, Qian Chen, Masahiko YachidaAbstract:This paper describes a new method to detect faces in Color images based on the fuzzy theory. We make two fuzzy models to describe the skin Color and hair Color, respectively. In these models, we use a perceptually Uniform Color Space to describe the Color information to increase the accuracy and stableness. We use the two models to extract the skin Color regions and the hair Color regions, and then comparing them with the prebuilt head-shape models by using a fuzzy theory based pattern-matching method to detect face candidates.
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face detection by fuzzy pattern matching
International Conference on Computer Vision, 1995Co-Authors: Qian Chen, Haiyuan Wu, Masahiko YachidaAbstract:The paper describes an approach to detect faces whose size and position are unknown in an image with a complex background. The candidates of faces are detected by finding out "face like" regions in the input image using the fuzzy pattern matching method. The perceptually Uniform Color Space is used in our research in order to obtain reliable results. The skin Color that is used to detect face like regions, is represented by a model developed by us called skin Color distribution function. The skin Color regions are then extracted by estimating a measure that describes how well the Color of a pixel looks like the skin Color for each pixel in the input image. The faces which appear in images are modeled as several 2 dimensional patterns. The face like regions are extracted by a fuzzy pattern matching approach using these face models. The face candidates are then verified by estimating how well the extracted facial features fit a face model which describes the geometrical relations among facial features. >
Alan Chalmers - One of the best experts on this subject based on the ideXlab platform.
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Uniform Color Space based high dynamic range video compression
IEEE Transactions on Circuits and Systems for Video Technology, 2019Co-Authors: Ratnajit Mukherjee, Kurt Debattista, Thomasbashford Rogers, Maximino Bessa, Alan ChalmersAbstract:Recently, there has been a significant progress in the research and development of the high dynamic range (HDR) video technology and the state-of-the-art video pipelines are able to offer a higher bit depth support to capture, store, encode, and display HDR video content. In this paper, we introduce a novel HDR video compression algorithm, which uses a perceptually Uniform Color opponent Space, a novel perceptual transfer function to encode the dynamic range of the scene, and a novel error minimization scheme for accurate chroma reproduction. The proposed algorithm was objectively and subjectively evaluated against four state-of-the-art algorithms. The objective evaluation was conducted across a set of 39 HDR video sequences, using the latest x265 10-bit video codec along with several perceptual and structural quality assessment metrics at 11 different quality levels. Furthermore, a rating-based subjective evaluation ( $n=40$ ) was conducted with six sequences at two different output bitrates. Results suggest that the proposed algorithm exhibits the lowest coding error amongst the five algorithms evaluated. Additionally, the rate–distortion characteristics suggest that the proposed algorithm outperforms the existing state-of-the-art at bitrates ≥ 0.4 bits/pixel.
