Auto-Exposure Algorithm Based on Luminance Histogram and Region Segmentation

2014 ◽  
Vol 543-547 ◽  
pp. 2278-2282 ◽  
Author(s):  
Zhi Hui Guo ◽  
Yuan Bao Gu ◽  
Hong Tao Yao
Keyword(s):  
Gain Control ◽  
Light Conditions ◽  
Region Segmentation ◽  
Average Brightness ◽  
Lighting Conditions ◽  
Average Luminance ◽  
Front Lighting ◽  
Reference Target ◽  
Normal Light ◽  
Partition Method

This paper proposed an automatic exposure algorithm based on luminance histogram and region segmentation. The method ensures well exposure to the main object under the backlighting or excessive front-lighting conditions, and uses the characteristics of the luminance histogram to judge the scene condition. According to the luminance histogram, if the image under normal light conditions, the method compares the average luminance value of the image with the corresponding reference target brightness value to adjust exposure compensation. If the image under special conditions, the average brightness value will be calculated using fixed-partition method and exposure compensation will be adjusted. The paper combines auto-exposure and auto-gain control to adjust the exposure compensation. As it turns out, this method in a variety of light conditions can achieve well exposure.

scholarly journals Morphological features of Hylotelephium triphillum (Haw.) Holub (Crassulaceae DC.) under different light conditions when introduced into the steppe zone

2016 ◽  
Vol 5 (2) ◽  
pp. 47-51
Author(s):  
Lidiya Vasilyevna Privalko
Keyword(s):  
Fruit Set ◽  
Steppe Zone ◽  
Botanical Garden ◽  
Light Conditions ◽  
Biometric Data ◽  
Habitat Features ◽  
Lighting Conditions ◽  
Air Temperatures ◽  
Natural Flora ◽  
The Impact

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.

scholarly journals Assessment the Visual Clarity of the Projector in Classroom and Innovative Asymmetric Distribution LED Tube Applications

2021 ◽  
Vol 11 (23) ◽  
pp. 11153
Author(s):  
Chun-Hsi Liu ◽  
Chun-Yu Hsiao ◽  
Jyh-Cherng Gu ◽  
Kuan-Yi Liu ◽  
Chih-Hung Chang ◽  
...  
Keyword(s):  
Vertical Plane ◽  
Asymmetric Distribution ◽  
Improvement Strategy ◽  
Vertical Projection ◽  
Lighting Conditions ◽  
Projection Screen ◽  
Switch Control ◽  
Average Luminance ◽  
And Performance ◽  
The Relationship

The paper aims to explore the relationship between the vertical plane luminance on projection screens and human visual clarity in the classroom or meeting room. While controlling the lighting environment conditions of the classroom to create different luminous distributions and luminance on the projection screen, a survey is conducted to understand students’ visual experience about screen clarity during the field experiment. The luminance of each picture on the projection screen is measured under the specified lighting conditions of luminaires in the classroom, and the relationship is formulated between the average luminance on the projection screen and the visual satisfaction based on clarity of experience. This will be useful for further studying the acceptable threshold of luminance distribution in the classroom to provide a better visual clarity and lighting quality of projection screens while teaching. In this study, the measurement and performance evaluation on a projection screen were carried out at a classroom in the National Taiwan University of Science and Technology (NTUST). By using an image luminance meter and analyzing the research results, we propose an improvement strategy for asymmetric luminous distribution design of LED light tube and light switch control mechanism of luminaires to resolve the inadequate luminance of the vertical projection screen area to improve the lighting quality and visual clarity of the projection screen while teaching with the least cost.

Evaluation of four insecticides to protect Nauclea diderrichii (Rubiaceae) seedlings against Orygmophora mediofoveata (Lepidoptera: Noctuidae) shoot borer damage

2017 ◽  
Vol 38 (01) ◽  
pp. 39-45 ◽  
Author(s):  
P.P. Bosu ◽  
E. Acquah ◽  
R.O. Boamah
Keyword(s):  
Seedling Survival ◽  
Iucn Red List ◽  
Tropical Rainforests ◽  
Light Conditions ◽  
Insecticide Treatment ◽  
Shoot Borer ◽  
Trade Name ◽  
Nauclea Diderrichii ◽  
Normal Light ◽  
Lepidoptera Noctuidae

AbstractNauclea diderrichii(De Wild and Th. Dür.) (common name Kusia and trade name, Opepe) is an evergreen tree found throughout the tropical rainforests of West Africa. It is heavily exploited for its timber and listed as vulnerable on the IUCN Red List of Threatened Species. The shoot borerOrygmophora mediofoveataHamps, which attacks the nursery stage, has hampered attempts to establishN. diderrichiiplantations in Ghana. This study examined the potential of four insecticides to protectN. diderrichiiseedlings fromO. mediofoveataattack and damage. Four insecticides–Pyrinex (chlorpyrifos), Dursban (chlorpyrifos), Cerox (dimethoate) and Golan (acetamiprid)–were applied to four-month-oldN. diderrichiiseedlings growing in full sunlight and under shade (80% of normal light), to evaluate their effects on incidence of attack, survival, severity of damage and growth. Insecticide treatment and light conditions had variable effects on the damage and growth of the seedlings after six months of evaluation. Seedling survival was not significantly influenced by the insecticide treatment. Percent survival of insecticide-treated seedlings did not differ significantly from that of control seedlings in full sun; however, under shade survival of treated seedlings was significantly higher than control seedlings. Nonetheless, control seedlings in full sun had higher survival (92.5%) than those under shade (62.5%). Insecticide-treated seedlings in full sun had lower incidence of shoot borer attack than those under shade. In full sun, dieback incidence following shoot borer attack was significantly lower for insecticide-treated than control seedlings. Growth in height and girth of seedlings was influenced positively by both insecticide and light, with girth especially being significantly lower under shade conditions. Currently,N. diderrichiiseedlings are typically raised under shade; however, this study shows that raising seedlings in full sun with insecticide application could result in faster and better growth.

scholarly journals Genetic Mapping of the Tomato Quality Traits Brix and Blossom-end Rot Under Supplemental LED and HPS Lighting Conditions

2021 ◽  
Author(s):  
Aina Prinzenberg ◽  
Hanneke van der Schoot ◽  
Richard GF Visser ◽  
Leo Marcelis ◽  
Ep Heuvelink ◽  
...  
Keyword(s):  
Genetic Locus ◽  
Chromosome 2 ◽  
Light Conditions ◽  
Chromosome 11 ◽  
Greenhouse Production ◽  
Lighting Conditions ◽  
Blossom End Rot ◽  
Supplemental Lighting ◽  
Brix Value ◽  
The Impact

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.

scholarly journals Smart Monitoring of the Status of Driver Using the Dashboard Vehicle Camera

2020 ◽  
Vol 9 (01) ◽  
pp. 01-07
Author(s):  
Dr. S. Praveen Chakkravarthy
Keyword(s):  
Elevated Level ◽  
Light Conditions ◽  
Specific Calculation ◽  
Lighting Conditions ◽  
The Status

One of the potential approaches to lessen the quantity of mishaps in rush hour gridlock is to follow the driver's condition. In this paper, a new driver observing calculation, which works on a video caught from the camera situated in the instrument board in the vehicle, is introduced. The calculation analyzes the nearness of the driver's head in each edge and checks whether the driver has bizarrely long closed eyes, regardless of whether the driver looks sideways, and whether the driver's head has dropped for quite a while. The calculation is tried utilizing ten unique recordings recorded under various light conditions. The calculation for the most part accomplishes superior, while for a few lighting conditions a specific calculation redesigning would be vital to keep up an elevated level of precision.

scholarly journals Limits of cross-modal plasticity? Short-term visual deprivation does not enhance cardiac interoception, thermosensation, or tactile spatial acuity

2021 ◽  
Author(s):  
Dominika Radziun ◽  
Laura Crucianelli ◽  
H. Henrik Ehrsson
Keyword(s):  
Healthy Volunteers ◽  
Washout Period ◽  
Visual Deprivation ◽  
Control Group ◽  
Light Conditions ◽  
Complete Darkness ◽  
Short Term ◽  
Experimental Conditions ◽  
Normal Light ◽  
Experimental Group

In the present study, we investigated the effect of short-term visual deprivation on discriminative touch, cardiac interoception, and thermosensation by asking 64 healthy volunteers to perform four behavioral tasks. The experimental group contained 32 subjects who were blindfolded and kept in complete darkness for 110 minutes, while the control group consisted of 32 volunteers who were not blindfolded but were otherwise kept under identical experimental conditions. Both groups performed the required tasks three times: before and directly after deprivation (or control) and after an additional washout period of 40 minutes, in which all participants were exposed to normal light conditions. Our results showed that short-term visual deprivation had no effect on any of the senses tested. This finding suggests that short-term visual deprivation does not modulate basic bodily senses and extends this principle beyond tactile processing to the interoceptive modalities of cardiac and thermal sensations.

scholarly journals Table top surface appraisal by school children under different lighting conditions tested in the Senselab

2019 ◽  
Vol 111 ◽  
pp. 02040 ◽  
Author(s):  
Marco A. Ortiz ◽  
Dadi Zhang ◽  
Philomena M. Bluyssen
Keyword(s):  
School Children ◽  
Test Chamber ◽  
Surface Finishing ◽  
Light Conditions ◽  
Lighting Conditions ◽  
Randomized Design

To find out whether a surface finishing was preferred under different lighting conditions by school children, in the light test chamber of the SenseLab, 335 children from previous studied schools were asked to assess a desk surface during different light conditions. A two-way randomized design was used to test children’s assessments for six school desks table tops (brown, yellow and grey wood, and, normal, matt and reflective white), under three different light conditions: energizing, calming, and focusing. A statistically relevant relationship was found for the three wooden surfaces, but none for the white ones. Such results may be due to the fact that better contrast between the participants’ form and the surface appeared with the wooden-like surfaces, as opposed to that with the white surfaces. Similarly, white surfaces’ characteristics seemed to be more difficult to assess (mattness, reflectiveness, opacity) as opposed to those for the wooden-like surfaces (colour yellow, brown, grey).

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