scholarly journals Preferred skin tones reproduction of three ethnic groups under different ambient lighting conditions

2020 ◽  
Vol 2020 (28) ◽  
pp. 94-99
Author(s):  
Mingkai Cao ◽  
Ming Ronnier Luo ◽  
Guoxiang Liu

A large-scale experiment was conducted to investigate facial image quality on mobile phones. There were 8 original facial images from 4 skin tone types, each included a male and a female image. Each image was captured at 6500K and they were rendered to have 5 CCT (correlated colour temperature) and 5 Duv (the shifts away from the Blackbody locus) levels via CAT02 chromatic adaptation transform to simulate the effect of the images captured under 25 different lighting conditions. Each image was assessed under 9 ambient lighting conditions( including one dark condition) by 90 observers from 3 ethnic groups (Caucasian, Chinese and South Asian), each 30 observers. Preferred facial skin tone ellipse was established by maximizing the correlation coefficient between the model predicted probability and the preference percentage from the visual results. Four types of preferred skin tones had small differences in hue angle and chroma, but concentrated into a small colour region, about [24.7, 46.1°] for Cab* and hab values respectively. All ethnic group preferred images taken under illuminants having high CCT (6500-8000 K). It was also found that the chroma of the preferred skin tones will slightly increase as the ambient lighting CCT decrease.

2020 ◽  
Vol 2020 (1) ◽  
pp. 10-14
Author(s):  
Mingkai Cao ◽  
Ming Ronnier Luo

This experiment was aimed to study the preference of mobile phone facial images captured under different simulated ambient lightings. The experiment was carried out by assessing the preference of images for two facial images under 11 lightings (5 correlated colour temperature levels at 2 illuminances plus a dark condition). Forty-five images were processed via CAT02 chromatic adaptation transform to simulate the pictures captured under different light environments. The results revealed that the preferred capture region was between 6500 and 8000K around -0.05 Duv. Furthermore, it was found that the preferred skin tones of all the 45 rendered had good agreement under all the ambient lightings of viewing, i.e.to have mean values of L*, Cab*, hab of [76.3 25.1, 46.4°] units under D65/10 o conditions.


2019 ◽  
Vol 2019 (1) ◽  
pp. 231-236
Author(s):  
Rui Peng ◽  
Ming Ronnier Luo ◽  
Mingkai Cao

The purposes of this study was to investigate the chromatic adaptation and adaptive whites on a display under various ambient lighting conditions with different chromaticity and illuminance. An image including black text and white background was rendered by means of the CAT02 chromatic adaptation transform, into 42 different white stimuli varying at 6 CCTs and 7 Duv levels. Twenty observers assessed the neutral white evaluations of each color stimulus via psychophysical experiments. The optimization based on the neutral white stimulus under each ambient lighting condition suggested a lower degree of chromatic adaptation under the conditions with a lower CCT and a lower illuminance level. The results were used to model the adaptive display white and the incomplete adaptation factor (D) for CAT02 under different ambient illumiantions.


2020 ◽  
Vol 2020 (28) ◽  
pp. 25-29
Author(s):  
Yan Lu ◽  
Jie Yang ◽  
Kaida Xiao ◽  
Michael Pointer ◽  
Changjun Li ◽  
...  

Previous research has shown the perceptual importance of skin tone appearance and how it contributes to perceived facial attractiveness, yet facial-colour perceptions may vary with different ethnic groups. This research was designed to explore the cross-cultural effects of the facial skin tone on perceived attractiveness between Caucasian (CA) and Chinese (CH) observers. 80 images of real human faces were used for facial attractiveness assessment by the two groups of observers using the categorical judgment method. The results showed overall similar preference but fine-scale differences in the perception of their own-ethnic facial images and other-ethnic facial images. Both groups of observers tended to use different criteria when judging the facial tone of different ethnic groups. Our findings show the aesthetic difference of different cultures in perceptions and underline the important role of ethnic differences with respect to skin tone preference.


2020 ◽  
Vol 26 (2) ◽  
Author(s):  
Alessandro Belmonte

AbstractThis paper investigates the consequences for inter-group conflicts of terrorist attacks. I study the 2015 Baga massacre, a large scale attack conducted by Boko Haram at the far North-East state of Borno, Nigeria, as a quasi-natural experiment and examine a set of attitudes in the aftermath of the event of Christians and Muslims throughout the country. Comparing individuals, outside the region of Borno, interviewed by Afrobarometer immediately after the massacre and those interviewed the days before within same regions and holding fixed a number of individual characteristics, I document that the informational exposure to the event rendered Christians less amiable to neighboring Muslims and Muslims less likely to recognize the legitimacy of the state. Nonetheless, Muslims increased their view of the elections as a device to remove leaders in office, event that took place 2 months later with the election of the challenger, Muhammadu Buhari. My findings indicate that terrorist attacks may generate a relevant and heterogeneous backlash across ethnic groups.


Mathematics ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 195
Author(s):  
Adrian Sergiu Darabant ◽  
Diana Borza ◽  
Radu Danescu

The human face holds a privileged position in multi-disciplinary research as it conveys much information—demographical attributes (age, race, gender, ethnicity), social signals, emotion expression, and so forth. Studies have shown that due to the distribution of ethnicity/race in training datasets, biometric algorithms suffer from “cross race effect”—their performance is better on subjects closer to the “country of origin” of the algorithm. The contributions of this paper are two-fold: (a) first, we gathered, annotated and made public a large-scale database of (over 175,000) facial images by automatically crawling the Internet for celebrities’ images belonging to various ethnicity/races, and (b) we trained and compared four state of the art convolutional neural networks on the problem of race and ethnicity classification. To the best of our knowledge, this is the largest, data-balanced, publicly-available face database annotated with race and ethnicity information. We also studied the impact of various face traits and image characteristics on the race/ethnicity deep learning classification methods and compared the obtained results with the ones extracted from psychological studies and anthropomorphic studies. Extensive tests were performed in order to determine the facial features to which the networks are sensitive to. These tests and a recognition rate of 96.64% on the problem of human race classification demonstrate the effectiveness of the proposed solution.


2015 ◽  
Vol 282 (1805) ◽  
pp. 20150120 ◽  
Author(s):  
Robert A. McCleery ◽  
Adia Sovie ◽  
Robert N. Reed ◽  
Mark W. Cunningham ◽  
Margaret E. Hunter ◽  
...  

To address the ongoing debate over the impact of invasive species on native terrestrial wildlife, we conducted a large-scale experiment to test the hypothesis that invasive Burmese pythons ( Python molurus bivittatus ) were a cause of the precipitous decline of mammals in Everglades National Park (ENP). Evidence linking pythons to mammal declines has been indirect and there are reasons to question whether pythons, or any predator, could have caused the precipitous declines seen across a range of mammalian functional groups. Experimentally manipulating marsh rabbits, we found that pythons accounted for 77% of rabbit mortalities within 11 months of their translocation to ENP and that python predation appeared to preclude the persistence of rabbit populations in ENP. On control sites, outside of the park, no rabbits were killed by pythons and 71% of attributable marsh rabbit mortalities were classified as mammal predations. Burmese pythons pose a serious threat to the faunal communities and ecological functioning of the Greater Everglades Ecosystem, which will probably spread as python populations expand their range.


Author(s):  
Stanley N. Roscoe ◽  
Scott G. Hasler ◽  
Dora J. Dougherty

The proficiency with which pilots can make takeoffs and landings using a periscope as the only source of outside visibility was studied under various conditions of flight. A detailed determination was made of the effects of variations in image magnification upon landing accuracy. Speed of transition to flight by periscope was related to flight experience. Effects of various weather, runway surface, and ambient lighting conditions upon flight by periscope were investigated.


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