Accurately estimating the spectral reflectance of art paintings from low-dimensional multichannel images requires that both image-acquisition hardware with appropriate spectral characteristics and appropriate estimation software be applied to the captured multichannel image. In this study, a system that incorporates both factors is designed and developed on the basis of the minimum-mean-square error criterion. The accuracy of spectral estimation by use of this system is evaluated, and the system's high performance is demonstrated.
Understanding metabolism in live microalgae is crucial for efficient biomaterial engineering, but conventional methods fail to evaluate heterogeneous populations of motile microalgae due to the labelling requirements and limited imaging speeds. Here, we demonstrate label-free video-rate metabolite imaging of live Euglena gracilis and statistical analysis of intracellular metabolite distributions under different culture conditions. Our approach provides further insights into understanding microalgal heterogeneity, optimizing culture methods and screening mutant microalgae.
The spatial distributions of melanin and hemoglobin in human skin are separated by independent-component analysis of a skin color image. The analysis is based on the skin color model with three assumptions: (1) Spatial variation of color in the skin is caused by two pigments, melanin and hemoglobin; (2) the quantities of the two pigments are mutually independent spatially; and (3) linearity holds among the quantities and the observed color signals in the optical density domain. The results of the separation agree well with physiological knowledge. The separated components are synthesized to simulate the various facial color images by changing the quantities of the two separated pigments.
This paper proposes an E-cosmetic function for digital images based on physics and physiologically-based image processing. A practical skin color and texture analysis/synthesis technique is introduced for this E-cosmetic function. Shading on the face is removed by a simple color vector analysis in the optical density domain as an inverse lighting technique. The image without shading is analyzed by a previously introduced technique that extracts hemoglobin and melanin components by independent component analysis. Experimental results using UV-B irradiation and the application of methyl nicotinate on the arms support the physiological validity of the analysis and the effectiveness of the proposed shading removal. We synthesized the way facial images changed due to tanning or alcohol consumption, and compared the synthesized images with images of actual changes in skin color. The comparison shows an excellent match between the synthesized and actual images of changes due to tanning and alcohol consumption. We also proposed a technique to synthesize the change of texture in pigment due to aging or the application of cosmetics. The pyramid-based texture analysis/synthesis technique was used for the spatial processing of texture. Using the proposed technique, we could realistically change the skin color and texture of a 50 year-old woman to that of a 20 year-old woman.
Abstract— A color management system (CMS) such as ICC profile or sRGB space have been proposed for color transformation and reproduction of cross media. In such a CMS, accurate colorimetric characterization of a display device plays a critical role in achieving device‐independent color reproduction. In the case of a CRT, colorimetric characterization based on a GOG model is accurate enough for this purpose. However, there is no effective counterpart in liquid‐crystal displays (LCDs) since the characterization of an LCD has many difficulties, such as channel interaction and non‐constancy of channel chromaticity. In this paper, a new method of display characterization is proposed which is applicable to the assessment of color reproduction of LCDs. The proposed method characterizes an electro‐optical transfer function considering both channel interaction and non‐constancy of channel chromaticity. Experimental results show that the proposed method is very effective in the colorimetry of LCDs.
The image of spectral absorbance in human skin is analyzed by independent component analysis. The spectral absorbance image is estimated from an image with red, green, and blue channels. The qualitative information and spatial distribution of the pigments can be extracted by the independent component analysis. It is shown that the extracted absorption characteristics of the pigments are corresponding to those of hemoglobin and melanin.
In order to satisfy the requirements of the cancelable biometrics construct, cancelable biometrics techniques rely on other authentication factors such as password keys and/or user specific tokens in the transformation process. However, such multi-factor authentication techniques suffer from the same issues associated with traditional knowledge-based and token-based authentication systems. This paper presents a new one-factor cancelable biometrics scheme for protecting IrisCodes. The proposed method is based solely on IrisCodes; however, it satisfies the requirements of revocability, diversity and noninvertibility without deteriorating the recognition performance. Moreover, the transformation process is easy to implement and can be integrated simply with current iris matching systems. The impact of the proposed transformation process on the the recognition accuracy is discussed and its noninvertibility is analyzed. The effectiveness of the proposed method is confirmed experimentally using CASIA-IrisV3-Interval dataset.
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