scholarly journals The impact of transition type on chromatic adaptation under dual lighting conditions

2020 ◽  
Vol 2020 (28) ◽  
pp. 36-41
Author(s):  
Shining Ma ◽  
Peter Hanselaer ◽  
Kees Teunissen ◽  
Kevin A.G. Smet

Over the years, many CATs (chromatic adaptation transform), typically based on the von Kries coefficient rule, have been developed to predict the corresponding colors under different illuminants. However, these CATs were derived for uniform stimuli surrounded by a uniform adapting field. To investigate the adaptation state under spatially complex illumination, an achromatic matching experiment was conducted under dual lighting conditions with three color pairs and two transition types. It has been found that the transition type has an impact on both the equivalent chromaticity and degree of adaptation. These results can help build a comprehensive von Kries based CAT model, with considering the spatial complexity of illumination.

2016 ◽  
Vol 5 (2) ◽  
pp. 47-51
Author(s):  
Lidiya Vasilyevna Privalko

In recent decades floral devices in a natural style has been becoming more common in gardening. In this connection there was a need for the introduction and study of the natural flora of plants in order to attract them to simulate the decorative and resistant plants. The article presents the results of studies of the effect of different light conditions on the habitat features and decorative biomorphological Hylotelephium triphyllum (Haw.) Holub (Crassulaceae DC.) when introduced in SE Donetsk Botanical Garden. This species is found naturally in the flora of Donbass, a decorative, but, according to the results of our analysis, is rarely used in green construction. Bioecological certification of this type has been done. It has been determined that the impact of site lighting conditions on the growth and development of H. triphyllum expressed in significantly smaller numbers of vegetative and generative shoots in the shaded areas. However, since the diameter of the plants does not change, more thickened planting in these areas is not recommended. The author found the dependence of the variation of the biometric data on the lighting conditions. In the study of seasonal dynamics of H. triphyllum the author revealed that the development of above-ground organs of his passes with a positive amount of average daily air temperatures. The growing season lasts an average of 225 days. Start of spring regrowth is observed in the second half of March - early April, flowering - in August - September, fruits - in September - October. Vegetation stops when temperature goes below zero. Illumination of this type of habitat affect the time of vegetation beginning, budding, flowering, fruit set and fruit-bearing. On the shaded areas due to the later start of budding and flowering the most decorative period of H. triphyllum is shorter by an average of 10 days. This type is recommended for creation of group planting, stony hills, dry streams, rock gardens, rockeries, mixborders, curbs, ornamental compositions in the coastal zone of ornamental ponds and fountains in the steppe zone in areas with different light conditions, taking into account the above factors.


Author(s):  
G. G. Derevyanska ◽  
O. Z. Glukhov

<p>This paper considers the problem of geographic links between the urban flora of steppe zone of Ukraine on the example of the industrial agglomeration Donetsk-Makeyevka, in comparison with urban flora of Kherson and Kirovograd. We presented the detailed description of special features of the composition of geographic elements of the agglomeration flora. It strongly reflects the characteristic features of steppe urban flora, because its territory is affected by the anthropogenic influence at large extend. The spectrum of geographic ranges of species from the agglomeration Donetsk-Makeyevka urban flora numbers 6 types, 12 classes and 130 groups of ranges. The urban flora is both represented by species with wide and local ranges, endemics, that point to its significant heterogeneity. However, compared to the flora of Kherson and Kirovograd, the role of holarctic type of ranges in the agglomeration flora (375 species compared to 400 and 522 species, respectively) is reduced in favor of the polyregional type, reflecting active adventization processes. The holarctic class itself is represented by 150 species (16.7%). It far exceeds the number of species of this class in the regional flora (9.2%), since nearly a half of their number in the observed flora is adventive species. Second place by the number of species in the holarctic class belongs to the European and North American group (13; 1.5%). Apart from this, seven more groups of the class, comprising 1-3 species each, are connected with North America. The polyregional type is represented to a large extent by the species of ruderal habitats. The total number of species of this type is 199. The palaearctic class includes the greatest number of ranges of species from the agglomeration urban flora (31); it consists of 175 species (19.5%), that is less than such index for regional flora (27.3%). The European and Old Mediterranean transition type comprises 97 species (10.8%), that is less than in other urban flora of steppe zone (128; 13.3% in Kherson and 171; 18.0% in Kirovograd). The Nomadic type numbers 132 species (14.7%). One more species – Verbascum marschallianum Ivanina et Tzvelev – is related to the Nomadic and European transition type. The Nomadic and Old Mediterranean transition type includes 93 species (10.4%). This all suggests heterogeneity of urban flora of steppe zone of Ukraine due to their wide geographic connections. On the one hand, they have features of regional flora, which was formed under the great influence of Old Mediterranean flora and has a significant number of narrow-range and endemic species. On the other hand, under the impact of urbanization one can observe the reduction of the role of ranges of the Nomadic type and the enhanced role of the polyregional type due to the significant number of adventive species.</p><p> </p>


2020 ◽  
Vol 11 (5) ◽  
pp. 37-60
Author(s):  
Chiman Kwan ◽  
Jude Larkin

In modern digital cameras, the Bayer color filter array (CFA) has been widely used. It is also widely known as CFA 1.0. However, Bayer pattern is inferior to the red-green-blue-white (RGBW) pattern, which is also known as CFA 2.0, in low lighting conditions in which Poisson noise is present. It is well known that demosaicing algorithms cannot effectively deal with Poisson noise and additional denoising is needed in order to improve the image quality. In this paper, we propose to evaluate various conventional and deep learning based denoising algorithms for CFA 2.0 in low lighting conditions. We will also investigate the impact of the location of denoising, which refers to whether the denoising is done before or after a critical step of demosaicing. Extensive experiments show that some denoising algorithms can indeed improve the image quality in low lighting conditions. We also noticed that the location of denoising plays an important role in the overall demosaicing performance.


2021 ◽  
Author(s):  
Aina Prinzenberg ◽  
Hanneke van der Schoot ◽  
Richard GF Visser ◽  
Leo Marcelis ◽  
Ep Heuvelink ◽  
...  

Abstract LED lighting has emerged as alternative to the current HPS standard in greenhouse production. However little is known about the impact on fruit quality under the different light spectra. We grew a biparental tomato RIL population between September 2019 and January 2020 under two commercial greenhouse supplemental lighting conditions, i.e. HPS, and 95% red/ 5% blue- LED, of about 220 µmol m− 2 s− 1 at maximum canopy height for 16h per day. Differences in Brix and blossom-end rot (BER) between the two light conditions were observed and we studied the genetic influences on those traits, separating genetics located on chromosomes from genetics located in plastids. The Brix value was on average 11% lower under LED than under HPS supplemental lighting. A LED-light specific QTL for Brix was identified on chromosome 6. This QTL can be of interest for breeding for tomato varieties cultivated under LED supplemental lighting. A Brix-QTL on chromosome 2 was found for both light conditions. In our study fewer plants developed BER under LED supplemental lighting than under HPS. We identified a novel genetic locus on chromosome 11 for the incidence of BER that lead to a difference in about 20% of fruits with BER. This genetic component was independent of the light.


2021 ◽  
Vol 67 (3) ◽  
pp. 148-154
Author(s):  
Jaroslav Kubišta ◽  
Peter Surový

Abstract Increasing availability of Unmanned aerial vehicles (UAV) and different software for processing of UAV imagery data brings new possibilities for on-demand monitoring of environment, making it accessible to broader spectra of professionals with variable expertise in image processing and analysis. This brings also new questions related to imagery quality standards. One of important characteristics of imagery is its spatial resolution as it directly impacts the results of object recognition and further imagery processing. This study aims at identifying relationship between spatial resolution of UAV acquired imagery and variables of imagery acquiring conditions, especially UAV flight height, flight speed and lighting conditions. All of these characteristics has been proved as significantly influencing spatial resolution quality and all subsequent data based on this imagery. Higher flight height as well as flight speed brings lower spatial resolution, whereas better lighting conditions lead to better spatial resolution of imagery. In this article we conducted a study testing various heights, flight speeds and light conditions and tested the impact of these parameters on Ground Resolved Distance (GRD). We proved that from among the variables, height is the most significant factor, second position is speed and finally the light condition. All of these factors could be relevant for instance in implementation of UAV in forestry sector, where imagery data must be often collected in diverse terrain conditions and/or complex stand (especially vertical) structure, as well as different weather conditions.


2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Pei Xie ◽  
Qing Li ◽  
Tong Zhu ◽  
Minghua Cao ◽  
Runqing Zhao

The vehicle color is considered to be a significant factor affecting driver visibility. The primary objective of this study is therefore to determine the impact of black-and-white striped vehicles (BWVs) on driver visibility through simulation-based experiments. In these experiments, subjects were asked to perform front and rear target identification tasks under daylight and twilight conditions. Then, a 2 (lighting conditions) × 2 (vehicle size) × 5 (vehicle color) analysis of variance was conducted for each task. Under the front identification scenario, the main factors affecting visibility were found to be lighting conditions, vehicle size, vehicle color, and the interactions between these factors. Under the rear identification scenario, lighting conditions and vehicle color were found to be the main factors. The results of this study demonstrate that driver visibility of BWVs is poorer than that of other colors of vehicles and that BWV visibility is susceptible to lighting conditions.


2021 ◽  
Vol 2021 (29) ◽  
pp. 368-373
Author(s):  
Yuechen Zhu ◽  
Ming Ronnier Luo

The goal of this study was to investigate the chromatic adaptation under extreme chromatic lighting conditions using the magnitude estimation method. The locations of the lightings on CIE1976 u′v′ plane were close to the spectrum locus, so the colour purity was far beyond the previous studies, and the data could test the limitations of the existing models. Two psychophysical experiments were carried out, and 1,470 estimations of corresponding colours were accumulated. The results showed that CAT16 gave a good prediction performance for all the chromatic lightings except for blue lighting, and the degree of adaptation was relatively high, that is, D was close to 1. The prediction for blue lightings was modified, the results showed the performance of CAM16 could be improved by correcting the matrix instead of the D values.


Sensors ◽  
2021 ◽  
Vol 21 (23) ◽  
pp. 8026
Author(s):  
Dariusz Pojda ◽  
Agnieszka Anna Tomaka ◽  
Leszek Luchowski ◽  
Michał Tarnawski

Multimodal imaging, including 3D modalities, is increasingly being applied in orthodontics, both as a diagnostic tool and especially for the design of intraoral appliances, where geometric accuracy is very important. Laser scanners and other precision 3D-imaging devices are expensive and cumbersome, which limits their use in medical practice. Photogrammetry, using ordinary 2D photographs or video recordings to create 3D imagery, offers a cheaper and more convenient alternative, replacing the specialised equipment with handy consumer cameras. The present study addresses the question of to what extent, and under what conditions, this technique can be an adequate replacement for the 3D scanner. The accuracy of simple surface reconstruction and of model embedding achieved with photogrammetry was verified against that obtained with a triangulating laser scanner. To roughly evaluate the impact of image imperfections on photogrammetric reconstruction, the photographs for photogrammetry were taken under various lighting conditions and were used either raw or with a blur-simulating defocus. Video footage was also tested as another 2D-imaging modality feeding data into photogrammetry. The results show the significant potential of photogrammetric techniques.


Energies ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 8002
Author(s):  
Katarzyna Bobkowska ◽  
Pawel Burdziakowski ◽  
Jakub Szulwic ◽  
Karolina M. Zielinska-Dabkowska

One of the most important elements during photogrammetric studies is the appropriate lighting of the object or area under investigation. Nevertheless, the concept of “adequate lighting” is relative. Therefore, we have attempted, based on experimental proof of concept (technology readiness level—TRL3), to verify the impact of various types of lighting emitted by LED light sources for scene illumination and their direct influence on the quality of the photogrammetric study of a 3D urban mock-up. An important issue in this study was the measurement and evaluation of the artificial light sources used, based on illuminance (E), correlated colour temperature (CCT), colour rendering index (CRI) and Spectral power distribution (SPD) and the evaluation of the obtained point clouds (seven photogrammetric products of the same object, developed for seven different lighting conditions). The general values of the quality of the photogrammetric studies were compared. Additionally, we determined seventeen features concerning the group of tie-points in the vicinity of each F-point and the type of study. The acquired traits were related to the number of tie-points in the vicinity, their luminosities and spectral characteristics for each of the colours (red, green, blue). The dependencies between the identified features and the obtained XYZ total error were verified, and the possibility of detecting F-points depending on their luminosity was also analysed. The obtained results can be important in the process of developing a photogrammetric method of urban lighting monitoring or in selecting additional lighting for objects that are the subject of a short-range photogrammetric study.


Sign in / Sign up

Export Citation Format

Share Document