Search results for "COLOR"
showing 10 items of 2721 documents
Intelligent eye
2010
This paper describes Intelligent Eye, a mobile phone interactive leisure guide that offers location-based multimedia information. The information offered is related to the user's position, so the main goal of this work is the development of an efficient system to detect where the user is pointing his/her camera at by means of a content-based image retrieval algorithm (CBIR). The CBIR procedure uses color histograms in the HS color space extracted from images, and employs Kullback-Leibler divergence as the similarity measure. Intelligent Eye can be used in a wide range of camera-equipped mobile phones; however, efficiency is improved if GPS data is available. In order to outperform other sys…
Analyzing the metrics of the perceptual space in a new multistage physiological colour vision model
2009
In this work, the metric of a new multistage colour vision model, ATTD05, is assessed and a new colour difference formula is suggested. Firstly, the uniformity of the ATTD05 colour space was compared with that of CIECAM02 for some Munsell samples, because if the model yields a uniform perceptual space, we will be able to implement a colour difference formula as a Euclidian distance between two points. Secondly, we developed a new space based on the perceptual descriptors of the model: brightness, hue, colourfulness, and saturation. After that, we calculated the free parameters of the space that better fit the measured and experimental data of two datasets (small-magnitude and large-magnitud…
Application Of Anamorphic Systems To Directional Pseudocolor Encoding
1988
An optical nonsymmetrical imaging system composed of two anamorphic spectrum analyzers in cascade is implemented. This system can provide an undistorted final image in spite of the geometrical distortion effects in the intermediate Fourier plane. The introduction of chromatic sector filters in this plane provides a real-time technique to pseudocolor encode the spatial frequency information of a black-and-white transparency. In this way, greater discrimination is achieved in the angular orientation of object details that generate the same spatial frequencies. Experimental pseudocolored images, obtained with a symmetrical system and a nonsymmetrical system, of a black-and-white transparency a…
How Quickly Can We Predict Users’ Ratings on Aesthetic Evaluations of Websites? Employing Machine Learning on Eye-Tracking Data
2020
This study examines how quickly we can predict users’ ratings on visual aesthetics in terms of simplicity, diversity, colorfulness, craftsmanship. To predict users’ ratings, first we capture gaze behavior while looking at high, neutral, and low visually appealing websites, followed by a survey regarding user perceptions on visual aesthetics towards the same websites. We conduct an experiment with 23 experienced users in online shopping, capture gaze behavior and through employing machine learning we examine how fast we can accurately predict their ratings. The findings show that after 25 s we can predict ratings with an error rate ranging from 9% to 11% depending on which facet of visual ae…
Robustness of texture parameters for color texture analysis
2006
This article proposes to deal with noisy and variable size color textures. It also proposes to deal with quantization methods and to see how such methods change final results. The method we use to analyze the robustness of the textures consists of an auto-classification of modified textures. Texture parameters are computed for a set of original texture samples and stored into a database. Such a database is created for each quantization method. Textures from the set of original samples are then modified, eventually quantized and classified according to classes determined from a precomputed database. A classification is considered incorrect if the original texture is not retrieved. This metho…
Electromagnetic spectrum and color vision
2004
In most of occasions the maps, drawings and printed images are elaborated thinking that the observer will visualize them with illuminants like the light of the day. With these illuminants, for example the CIE D/sub 65/, we can distinguish the great quantity of colors that it is capable the human eye. But if the illuminant has a very different spectrum than the light of day, for example the light of acetylene, the number of colors that we are able to distinguish can decrease drastically.
Enhanced detection of contrast regions in echocardiograms by adaptive quantization
2002
The statistics of ultrasound echo images are governed by Rayleigh statistics. The authors derive some experimentally verifiable predictions of this theory, compare them with experimental results obtained from echocardiographic images, and derive a new color coding scheme, (adaptive quantization) that is adapted to the signal-dependent noise predicted by theory. This results in some technical advantages and in an improved discrimination of regions of the echo image that are enhanced by echo contrast material. >
Tooth discoloration and internal bleaching after the use of ledermix paste with various bleaching agents ? An in vitro study
2018
Background To assess the reversal of discolouration caused by Ledermix using various bleaching agents. Material and Methods Twenty six extracted human mandibular premolars were taken and divided into four groups. Six teeth were divided into three each which are taken as positive and negative controls. The remaining twenty are divided into two groups (n=10). After conventional access preparation, the Ledermix paste was sealed in the pulp chamber for twelve weeks. The paste was removed by a rinse with sodium hypochlorite (NaOCl). Then the pulp chamber was sealed with a mixture of Sodium perborate and distilled water for group 1 and group 2 was sealed with Sodium tetraborate for 1 to 12 weeks.…
Concerning the calculation of the color gamut in a digital camera
2006
Several methods to determine the color gamut of any digital camera are shown. Since an input device is additive, its color triangle was obtained from their spectral sensitivities and it was compared with the theoretical sensors of Ives-Abney-Yule and MacAdam. On the other hand, the RGB digital data of the optimal or MacAdam colors were simulated to transform them into XYZ data according to the colorimetric profile of the digital camera. From this, the MacAdam limits associated to the digital camera are compared with the corresponding ones of the CIE-1931 XYZ standard observer, resulting that our color device has much smaller MacAdam loci than those of the colorimetric standard observer. Tak…
<title>Stereoacuity determination at changing contrast of colored stereostimuli</title>
2003
Studies are focused on design and appraisal of an objective test for assessment of the stereovision quality in unfavorable conditions. Stereostimuli of different colors are used while the contrast of one of the stimulus being varied. Tests are based on principles of black-and-white and two primary color random dot stereotests. Experiments are divided by the method of stimuli display and separation: 1) stereoeffect is obtained haploscopically - by use of spectacles with color filters (blue and red) or prisms, 2) stimuli separation is obtained by liquid crystal shutters when both eye stimuli are demonstrated with a different delay. The stereovision threshold is determiend at different stimuli…