The color perception is related to color objects, vision system and central nervous system. The methods of evaluation, classification and prediction of the color perception are investigated and analyzed in this paper....The color perception is related to color objects, vision system and central nervous system. The methods of evaluation, classification and prediction of the color perception are investigated and analyzed in this paper. The artificial neural networks are used for color perception, clustering and predicting based on the given data obtained from both objective measurement and subjective evaluation.展开更多
The advantage of electronic devices is to eliminate the subjectivity. Based on individual capabilities, visual perception has its disadvantages. The aim of this study was to find out the possible shade difference betw...The advantage of electronic devices is to eliminate the subjectivity. Based on individual capabilities, visual perception has its disadvantages. The aim of this study was to find out the possible shade difference between the upper and lower teeth, visual perception versus spectrophotometry as well as proving that females are better in visual perception of colour matching. 82 subjects (dental students) of this study determined the color of each other’s natural teeth. The color of 1640 teeth (incisors, canines and premolars), was matched by visual perception and by Vita Easyshade spectrophotometer. The matching was focused on the middle third of buccal surfaces of the examined teeth. In this study, it was found that there was a difference of color between the teeth of the upper and lower jaw. The percentage of the accordance between two methods was 28.35% for all examined teeth. The color determination at central incisors showed the highest value of accordance 40.85%. Based on Vitapan 3D Mastershade, the most frequent color was 2M2.展开更多
Purpose: To investigate the characteristics of interaction between color and motion perception in primary open angle glaucoma (POAG) and measure motion perception of B,G and R cones, thus find a more sensitive method ...Purpose: To investigate the characteristics of interaction between color and motion perception in primary open angle glaucoma (POAG) and measure motion perception of B,G and R cones, thus find a more sensitive method to diagnose the visual nerve damage in POAG. Methods : Motion perceptions of B,G and R cones were isolated by blue , green and red vertical line stimulus displayed on the yellow , purple and blue background respectively, then measured the displacement threshold and flicking threshold of motion perception from each cones in POAG, and compared it with the age-match normals.Results:The displacement threshold and flicking threshold of motion perception from B,G and R cones were all damaged in POAG compared with the normals, and the motion perception of G and B cones was deficits more obviously than the R cones.Conclusion: These findings support the suggestion that color provides an input to human motion perception. Magnocellular and parvocellular pathway may be significandy damaged in POAG,展开更多
AIM:To compare the visual perception(color and chromatic-achromatic contrast vision)of a small cohort of COVID-19 patients at the time of infection and after 6mo with that of a healthy population matched for sex and a...AIM:To compare the visual perception(color and chromatic-achromatic contrast vision)of a small cohort of COVID-19 patients at the time of infection and after 6mo with that of a healthy population matched for sex and age.METHODS:A total of 25 patients(9 females,16 males,mean age:54±10y)with COVID-19 hospitalized in the COVID-19 Unit of the University Clinical Hospital of Valladolid were recruited for this preliminary study.Visual perception,as determined by monocular measurement of contrast sensitivity function(CSF)and color vision was assessed in each patient using the Optopad test.The results obtained were then compared with those of a sample of 16 age-and sex-matched healthy controls(5 females,11 males,mean age:50±6y)in which the same measurement procedure was repeated.Statistically significant differences between groups were assessed using the Mann-Whitney U test.Measurements were repeated after a minimum follow-up period of 6mo and statistically significant differences between the two time points in each group were assessed using the Wilcoxon signed rank test.RESULTS:Discrimination thresholds(color and chromatic-achromatic contrast vision)and their corresponding sensitivity,calculated as the inverse of the discrimination threshold,were evaluated.Analysis of the data revealed higher contrast threshold results(i.e.,worse contrast sensitivity)in the COVID-19 group than in the control group for all spatial frequencies studied in the Optopad-CSF achromatic test and most of the spatial frequencies studied in the Optopad-CSF chromatic test for the red-green and blue-yellow mechanisms.In addition,color threshold results in the COVID-19 group were also significantly higher(i.e.,worse color sensitivity)for almost all color mechanisms studied in the Optopad-Color test.At 6mo,most of the differences found between the groups were maintained despite COVID-19 recovery.CONCLUSION:The present results provide preliminary evidence that visual perception may be impaired in COVID-19,even when the infection has passed.Although further research is needed to determine the precise causes of this finding,analysis of CSF and color vision could provide valuable information on the visual impact of COVID-19.展开更多
The possibility of having flying machines in complex natural environments presents many exciting possibilities, but also technical challenges. Insects often rely on visual cues for flight and decision making, and rece...The possibility of having flying machines in complex natural environments presents many exciting possibilities, but also technical challenges. Insects often rely on visual cues for flight and decision making, and recent work suggests that the perception of wind force through tactile sensory inputs also provides important information for flight control. However, the extent to which these respective cues might potentially be bound together in the brain to enable accurate decisions remains untested. Here we discuss recent evidence that the brain of insects possesses mechanisms that may allow for the binding of complex multisensory information, and we propose an experiment that could dissect whether insects like bees may have such a capacity. We additionally discuss areas of the bee brain that might facilitate decision making in order to provide a road map forward for future work on understanding the mechanisms of flying in complex natural environments.展开更多
To investigate quantitatively one of the parametric effects——simultaneous color contrast on color appearance and color difference evaluation in complex displays, a set of center/surround combinations of color stimu...To investigate quantitatively one of the parametric effects——simultaneous color contrast on color appearance and color difference evaluation in complex displays, a set of center/surround combinations of color stimuli were displayed on a color monitor and the perceived color shifts of test targets induced by its surrounds were measured using binocular matching method while systematically varying hue difference between target and surround. When the hue difference increased, the magnitude of color shift in test target decreased, but the deflection angle of color shift vector from constant hue line increased. Regression analyses of experimental data indicated that the relationship between hue angle difference and the magnitude of perceived color shifts could be described quantitatively by an exponential function, and a linear function could describe quantitative relationship between hue angle difference and deflection angle of color shift vector from constant hue line.展开更多
RGB displays effectively simulate millions of colors in the eyes of humans by modulating the rela-tive amount of light emitted by 3 differently colored juxtaposed lights （red, green, and blue）. Therelationship betwe...RGB displays effectively simulate millions of colors in the eyes of humans by modulating the rela-tive amount of light emitted by 3 differently colored juxtaposed lights （red, green, and blue）. Therelationship between the ratio of red, green, and blue light and the perceptual experience of thatlight has been well defined by psychophysical experiments in humans, but is unknown in animals.The perceptual experience of an animal looking at an RGB display of imagery designed for humansis likely to poorly represent an animal＇s experience of the same stimulus in the real world. This isdue, in part, to the fact that many animals have different numbers of photoreceptor classes thanhumans do and that their photoreceptor classes have peak sensitivities centered over differentparts of the ultraviolet and visible spectrum. However, it is sometimes possible to generate videosthat accurately mimic natural stimuli in the eyes of another animal, even if that animal＇s sensitivityextends into the ultraviolet portion of the spectrum. How independently each RGB phosphor stimu-lates each of an animal＇s photoreceptor classes determines the range of colors that can be simu-lated for that animal. What is required to determine optimal color rendering for another animal is adevice capable of measuring absolute or relative quanta of light across the portion of the spectrumvisible to the animal （i.e., a spectrometer）, and data on the spectral sensitivities of the animal＇sphotoreceptor classes. In this article, we outline how to use such equipment and information togenerate video stimuli that mimic, as closely as possible, an animal＇s color perceptual experienceof real-world objects.展开更多
Female cichlid fish living in African great lakes are known to have sensory systems that are adapted to ambient light environments.These sen-sory system adaptations are hypothesized to have influenced the evolution of...Female cichlid fish living in African great lakes are known to have sensory systems that are adapted to ambient light environments.These sen-sory system adaptations are hypothesized to have influenced the evolution of the diverse male nuptial coloration.In rock-dwelling Lake Malawi mbuna cichlids,however,the extent to which ambient light environments influence female sensory systems and potentially associated male nuptial coloration remains unknown.Yet,the ubiquitous blue flank coloration and UV reflection of male mbuna cichlids suggest the potential impacts of the blue-shifted ambient light environment on these cichlid's visual perception and male nuptial coloration in the shallow water depth in Lake Malawi.In the present study,we explored whether and how the sensory bias of females influences intersexual communication in the mbuna cichlid,Metriaclima zebra.A series of choice experiments in various light environments showed that M.zebra females (1)have a pref-erence for the blue-shifted light environment,(2)prefer to interact with males in blue-shifted light environments,(3)do not show a preference between dominant and subordinate males in full-spectrum,long-wavelength filtered,and short-wavelength filtered light environments,and (4)show a"reversed"preference for subordinate males in the UV-filtered light environment.These results suggest that the visual perception of M.zebra females may be biased to the ambient light spectra in their natural habitat by local adaptation and that this sensory bias may influence the evolution of blueand UV reflectivepatterns in male nuptial coloration.展开更多
China’s construction has entered the high-quality development stage,and the building color landscape as the constituent element of the quality of urban artificial landscape has attracted more and more attention.In th...China’s construction has entered the high-quality development stage,and the building color landscape as the constituent element of the quality of urban artificial landscape has attracted more and more attention.In the process of building the building color evaluation system with the appeal of“public participation”,it is necessary to absorb and adopt public opinions,and the color planning practice cannot completely match the public opinions.In this paper,Pingguoyuan Street in Beijing City was taken as an example,and factor grading was constructed based on the relevant principle of“sensitivity grading”by analyzing the coupling relationship between color and urban artificial landscape structure.GIS technology was used to integrate and analyze residents’color sensitivity data obtained by investigation and interview and form the psychological evaluation of residents’color perception of artificial landscape,so as to provide scientific basis for the color planning of Pingguoyuan Street in Beijing City from the perspective of“space justice”.展开更多
Depth perception for night vision （NV） imagery could largely improve scene comprehension. We present a novel scheme to give fused multi-band NV imagery smoothly natural color appearance as well as depth sense from c...Depth perception for night vision （NV） imagery could largely improve scene comprehension. We present a novel scheme to give fused multi-band NV imagery smoothly natural color appearance as well as depth sense from color. Our approach is based on simulating color cues by varying saturation values of each object in the color NV image, in correspondence with the ratio between the infrared and low-light-level sensor outputs which in practice is the depth feature for same materials. We render the NV image segment- by-segment by taking advantage image fusion. Experiments have of image segmentation, dominant shown that the proposed scheme color transfer, saturation variation, and can achieve satisfying results.展开更多
文摘The color perception is related to color objects, vision system and central nervous system. The methods of evaluation, classification and prediction of the color perception are investigated and analyzed in this paper. The artificial neural networks are used for color perception, clustering and predicting based on the given data obtained from both objective measurement and subjective evaluation.
文摘The advantage of electronic devices is to eliminate the subjectivity. Based on individual capabilities, visual perception has its disadvantages. The aim of this study was to find out the possible shade difference between the upper and lower teeth, visual perception versus spectrophotometry as well as proving that females are better in visual perception of colour matching. 82 subjects (dental students) of this study determined the color of each other’s natural teeth. The color of 1640 teeth (incisors, canines and premolars), was matched by visual perception and by Vita Easyshade spectrophotometer. The matching was focused on the middle third of buccal surfaces of the examined teeth. In this study, it was found that there was a difference of color between the teeth of the upper and lower jaw. The percentage of the accordance between two methods was 28.35% for all examined teeth. The color determination at central incisors showed the highest value of accordance 40.85%. Based on Vitapan 3D Mastershade, the most frequent color was 2M2.
基金This research was supported by National Nature Science Foundation,NO.39470743
文摘Purpose: To investigate the characteristics of interaction between color and motion perception in primary open angle glaucoma (POAG) and measure motion perception of B,G and R cones, thus find a more sensitive method to diagnose the visual nerve damage in POAG. Methods : Motion perceptions of B,G and R cones were isolated by blue , green and red vertical line stimulus displayed on the yellow , purple and blue background respectively, then measured the displacement threshold and flicking threshold of motion perception from each cones in POAG, and compared it with the age-match normals.Results:The displacement threshold and flicking threshold of motion perception from B,G and R cones were all damaged in POAG compared with the normals, and the motion perception of G and B cones was deficits more obviously than the R cones.Conclusion: These findings support the suggestion that color provides an input to human motion perception. Magnocellular and parvocellular pathway may be significandy damaged in POAG,
基金Supported by the Institute of Health CarlosⅢ(No.COV20/00539)。
文摘AIM:To compare the visual perception(color and chromatic-achromatic contrast vision)of a small cohort of COVID-19 patients at the time of infection and after 6mo with that of a healthy population matched for sex and age.METHODS:A total of 25 patients(9 females,16 males,mean age:54±10y)with COVID-19 hospitalized in the COVID-19 Unit of the University Clinical Hospital of Valladolid were recruited for this preliminary study.Visual perception,as determined by monocular measurement of contrast sensitivity function(CSF)and color vision was assessed in each patient using the Optopad test.The results obtained were then compared with those of a sample of 16 age-and sex-matched healthy controls(5 females,11 males,mean age:50±6y)in which the same measurement procedure was repeated.Statistically significant differences between groups were assessed using the Mann-Whitney U test.Measurements were repeated after a minimum follow-up period of 6mo and statistically significant differences between the two time points in each group were assessed using the Wilcoxon signed rank test.RESULTS:Discrimination thresholds(color and chromatic-achromatic contrast vision)and their corresponding sensitivity,calculated as the inverse of the discrimination threshold,were evaluated.Analysis of the data revealed higher contrast threshold results(i.e.,worse contrast sensitivity)in the COVID-19 group than in the control group for all spatial frequencies studied in the Optopad-CSF achromatic test and most of the spatial frequencies studied in the Optopad-CSF chromatic test for the red-green and blue-yellow mechanisms.In addition,color threshold results in the COVID-19 group were also significantly higher(i.e.,worse color sensitivity)for almost all color mechanisms studied in the Optopad-Color test.At 6mo,most of the differences found between the groups were maintained despite COVID-19 recovery.CONCLUSION:The present results provide preliminary evidence that visual perception may be impaired in COVID-19,even when the infection has passed.Although further research is needed to determine the precise causes of this finding,analysis of CSF and color vision could provide valuable information on the visual impact of COVID-19.
文摘The possibility of having flying machines in complex natural environments presents many exciting possibilities, but also technical challenges. Insects often rely on visual cues for flight and decision making, and recent work suggests that the perception of wind force through tactile sensory inputs also provides important information for flight control. However, the extent to which these respective cues might potentially be bound together in the brain to enable accurate decisions remains untested. Here we discuss recent evidence that the brain of insects possesses mechanisms that may allow for the binding of complex multisensory information, and we propose an experiment that could dissect whether insects like bees may have such a capacity. We additionally discuss areas of the bee brain that might facilitate decision making in order to provide a road map forward for future work on understanding the mechanisms of flying in complex natural environments.
文摘To investigate quantitatively one of the parametric effects——simultaneous color contrast on color appearance and color difference evaluation in complex displays, a set of center/surround combinations of color stimuli were displayed on a color monitor and the perceived color shifts of test targets induced by its surrounds were measured using binocular matching method while systematically varying hue difference between target and surround. When the hue difference increased, the magnitude of color shift in test target decreased, but the deflection angle of color shift vector from constant hue line increased. Regression analyses of experimental data indicated that the relationship between hue angle difference and the magnitude of perceived color shifts could be described quantitatively by an exponential function, and a linear function could describe quantitative relationship between hue angle difference and deflection angle of color shift vector from constant hue line.
文摘RGB displays effectively simulate millions of colors in the eyes of humans by modulating the rela-tive amount of light emitted by 3 differently colored juxtaposed lights （red, green, and blue）. Therelationship between the ratio of red, green, and blue light and the perceptual experience of thatlight has been well defined by psychophysical experiments in humans, but is unknown in animals.The perceptual experience of an animal looking at an RGB display of imagery designed for humansis likely to poorly represent an animal＇s experience of the same stimulus in the real world. This isdue, in part, to the fact that many animals have different numbers of photoreceptor classes thanhumans do and that their photoreceptor classes have peak sensitivities centered over differentparts of the ultraviolet and visible spectrum. However, it is sometimes possible to generate videosthat accurately mimic natural stimuli in the eyes of another animal, even if that animal＇s sensitivityextends into the ultraviolet portion of the spectrum. How independently each RGB phosphor stimu-lates each of an animal＇s photoreceptor classes determines the range of colors that can be simu-lated for that animal. What is required to determine optimal color rendering for another animal is adevice capable of measuring absolute or relative quanta of light across the portion of the spectrumvisible to the animal （i.e., a spectrometer）, and data on the spectral sensitivities of the animal＇sphotoreceptor classes. In this article, we outline how to use such equipment and information togenerate video stimuli that mimic, as closely as possible, an animal＇s color perceptual experienceof real-world objects.
文摘Female cichlid fish living in African great lakes are known to have sensory systems that are adapted to ambient light environments.These sen-sory system adaptations are hypothesized to have influenced the evolution of the diverse male nuptial coloration.In rock-dwelling Lake Malawi mbuna cichlids,however,the extent to which ambient light environments influence female sensory systems and potentially associated male nuptial coloration remains unknown.Yet,the ubiquitous blue flank coloration and UV reflection of male mbuna cichlids suggest the potential impacts of the blue-shifted ambient light environment on these cichlid's visual perception and male nuptial coloration in the shallow water depth in Lake Malawi.In the present study,we explored whether and how the sensory bias of females influences intersexual communication in the mbuna cichlid,Metriaclima zebra.A series of choice experiments in various light environments showed that M.zebra females (1)have a pref-erence for the blue-shifted light environment,(2)prefer to interact with males in blue-shifted light environments,(3)do not show a preference between dominant and subordinate males in full-spectrum,long-wavelength filtered,and short-wavelength filtered light environments,and (4)show a"reversed"preference for subordinate males in the UV-filtered light environment.These results suggest that the visual perception of M.zebra females may be biased to the ambient light spectra in their natural habitat by local adaptation and that this sensory bias may influence the evolution of blueand UV reflectivepatterns in male nuptial coloration.
文摘China’s construction has entered the high-quality development stage,and the building color landscape as the constituent element of the quality of urban artificial landscape has attracted more and more attention.In the process of building the building color evaluation system with the appeal of“public participation”,it is necessary to absorb and adopt public opinions,and the color planning practice cannot completely match the public opinions.In this paper,Pingguoyuan Street in Beijing City was taken as an example,and factor grading was constructed based on the relevant principle of“sensitivity grading”by analyzing the coupling relationship between color and urban artificial landscape structure.GIS technology was used to integrate and analyze residents’color sensitivity data obtained by investigation and interview and form the psychological evaluation of residents’color perception of artificial landscape,so as to provide scientific basis for the color planning of Pingguoyuan Street in Beijing City from the perspective of“space justice”.
基金supported by the National Natural Science Foundation of China(No.60502042)the Shanghai Rising-Star Program(No.06QA14003)
文摘Depth perception for night vision （NV） imagery could largely improve scene comprehension. We present a novel scheme to give fused multi-band NV imagery smoothly natural color appearance as well as depth sense from color. Our approach is based on simulating color cues by varying saturation values of each object in the color NV image, in correspondence with the ratio between the infrared and low-light-level sensor outputs which in practice is the depth feature for same materials. We render the NV image segment- by-segment by taking advantage image fusion. Experiments have of image segmentation, dominant shown that the proposed scheme color transfer, saturation variation, and can achieve satisfying results.
