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UV-spectrophotometer is light absorbance measurement device. It is used to measure the solution for checking the concentration. However, it is very expensive. This is a problem for the chemical education which doesn't have this device enough for every student. It is not difficult to create the hand-made spectrophotometer. However, it is difficult to get the data same with the spectrophotometer. We...
How to choose lighting source to enhance a gratifying ambience so as to improve impression and evaluation of the fruits was investigated in this study. Firstly, a laboratory functioning with controllable LED light source and physical quantity measurement was constructed. Secondly, subjective visual satisfaction experiments on the testees with LED light source combining with different color temperature,...
The appearance of an object depends on the color as well as the direction of a light source illuminating the object. The progress of LEDs enables us to capture the images of an object under multispectral and multidirectional light sources. Separating diffuse and specular reflection components in those images is important for preprocessing of various computer vision techniques such as photometric stereo,...
The acquisition of surface material properties and lighting conditions is a fundamental step for photo-realistic Augmented Reality (AR). In this paper, we present a new method for the estimation of diffuse and specular reflectance properties of indoor real static scenes. Using an RGB-D sensor, we further estimate the 3D position of light sources responsible for specular phenomena and propose a novel...
The work documented in this paper gives a working knowledge of mapping the spectral lines in the emission spectra of physical objects to their corresponding wavelengths. In simpler terms RGB triplets in the spectrogram image are mapped to their corresponding wavelengths on the visible spectrum. Peaks of CIE RGB color matching functions are directly mapped one on one to peaks of the R, G and B intensity...
An approach to detect and remove cast shadows of moving objects was proposed in this paper. Gaussian mixture model with only one learning rate a was used for background subtraction and modeling. Initial classification of foreground pixels into object pixels and shadow pixels were performed using saturation property of HSV color space. In the hue difference or brightness ratio based shadow detection...
This paper presents photometric and geometric measurement methods based on a multi-primary image projector. The projector is primarily configured with a light source component and an image projection component. The light source, which can be programmed vis a computer, can reproduce any spectral curve. Spatial images are projected by a digital mirror device (DMD) chip that provides rapid control of...
In this paper, a back lighting color image enhancement method using color saturation and image fusion is presented. First, the saturation component of color image is computed by using HSV or HSI color space. Then, two different exposed images are generated by using weighting function method. Next, the enhanced image is obtained by fusing input color image and two different exposed images. Finally,...
This paper deals with design and development of a device used for measurement of colour changes of granulate polymer material which is produced by recycling technology. Individual parts of design from the point of hardware and software are described. Description of user application in MATLAB programming environment is introduced. Relative measurement of reference sample set is also presented.
Metamerism is a phenomenon where two objects recognized as having different colors under one light are also recognized as having the same color under another light. This research proposes technology for actualizing artistic illusion that exploits metamerism. Specifically, the purpose of the research relates to automatic calculation of blending ratios of oil paints that cause metamerism to occur under...
The optimization matching procedure for specific LED spectrum matching is proposed by the normalized correlation coefficient and generalized reduced gradient method in this study. The different spectrum means different color temperature, color rendering index, and lighting quality features. However, the specific spectrum for human centric lighting or light therapy may not be achieved by single light...
We demonstrate the first array of asynchronous event pixels that react to temporal color contrast of three different color spectra. The three different spectra are transduced into photo currents by stacked photo diodes. Temporal changes of the contrast of these three spectra are quantified as pulse density modulated signals and conveyed off-chip by the Address Event Representation (AER) protocol....
This paper investigates the correlation between color quality and energy efficiency of indoor lighting control. The color quality, in terms of visual performance and comfort, is quantified using three measurements: illuminance, Color Rendering Index, and Correlated Color Temperature. Several experiments have been conducted to evaluate the potential energy savings of using different portions of light...
Working under low light conditions is of particular interest in machine vision applications such as night vision, tone-mapping techniques, low-light imaging, photography, and surveillance cameras. This work aims at investigating the perception of color at low light situations imposed by physical principles governing photon emission. The impact of the probabilistic nature of photon emission on our...
Knowing the RGB spectral sensitivities of a camera is useful for several image processing applications. However, camera manufacturers seldom provide this information. Calibration methods for determining them can be daunting, requiring either sophisticated instruments or carefully controlled lighting. This paper presents a quick and easy method that provides a reasonable approximation of the camera...
Metamerism is a phenomenon where two objects recognized as having different colors under one light are also recognized as having the same color under another light. This research proposes technology for actualizing artistic illusion that exploits metamerism. Specifically, the purpose of the research relates to automatic calculation of blending ratios of oil paints that cause metamerism to occur under...
The aim of this research is to evaluate the performance of different uniform colour spaces and colour rendering indices on the colour fidelity of light sources. To achieve this aim, a psychophysical experiment was carried out which invited 10 observers to assess the colour differences of the identical samples viewed under two sources, using simultaneous colour matching and grey scale method. Percentages...
The color is a feature derived from perceptual light that is reflected on objects, as such, represents a physical property. However, progress has been made in building mathematical models to define it more clearly. Light sources play an important role in the perception of colors and one of the measures to characterize their effect is the Correlated Color Temperature (CCT). The CCT is a measure used...
Specularity is a common phenomenon in the real world and can provide both challenges and opportunities for computer vision algorithms. In this paper, we propose a new method to detect specularities in real time. This method is based on an unnormalized version of the Wiener Entropy which is commonly used in audio spectral analysis. Experiment results demonstrate our proposed methodology's efficacy...
Robust people re-identification is one of the most challenging task, and still an unsolved problem for several applications in video surveillance. A large number of approaches use colors as main features for object description, which are in fact important cues for re-identification. However, colors captured by a camera suffer from unknown and changing global and local illumination conditions in the...
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