48 research outputs found

    Single-image RGB Photometric Stereo With Spatially-varying Albedo

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    We present a single-shot system to recover surface geometry of objects with spatially-varying albedos, from images captured under a calibrated RGB photometric stereo setup---with three light directions multiplexed across different color channels in the observed RGB image. Since the problem is ill-posed point-wise, we assume that the albedo map can be modeled as piece-wise constant with a restricted number of distinct albedo values. We show that under ideal conditions, the shape of a non-degenerate local constant albedo surface patch can theoretically be recovered exactly. Moreover, we present a practical and efficient algorithm that uses this model to robustly recover shape from real images. Our method first reasons about shape locally in a dense set of patches in the observed image, producing shape distributions for every patch. These local distributions are then combined to produce a single consistent surface normal map. We demonstrate the efficacy of the approach through experiments on both synthetic renderings as well as real captured images.Comment: 3DV 2016. Project page at http://www.ttic.edu/chakrabarti/rgbps

    A preliminary study on the fishery resources of the mangrove swamps of Sundarbans, West Bengal

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    West Bengal holds an important position in fisheries development as the state has all types of captive, culture freshwater and brackish water fisheries. A survey of forest areas of Sundarbans indicates the total annual catch to be 2500 metric tonnes. On average 4,000 persons are engaged in daily fishing with 1.5 kilogrammes of fish catch per fisherman per day and during the 6 months from September to February on an average 6,000 persons are engaged in fishing. About 70% of total catch of fish is collected during this period. Statistical analysis of the data collected for the study has clearly indicated that a rational and scientific exploitation of fish species inhabiting the rivers and creeks of Sundarbans estuary has immense economic potentialities

    Electron collision studies on the CH2+_2^+ molecular ion

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    Calculations are performed for electron collision with the methylene molecular ion CH2+_2^+ in its bent equilibrium geometry, with the goal to obtain cross sections for electron impact excitation and dissociation. The polyatomic version of the UK molecular \Rmat codes was used to perform an initial configuration-interaction calculation on the doublet and quartet states of the CH2+_2^+ ion. Subsequently, scattering calculations are performed to obtain electron impact electronic excitation and dissociation cross sections and, additionally, the bound states of the CH2_2 molecule and Feshbach resonances in the ee-CH2+_2^+ system

    Culture independent molecular analysis of bacterial communities in the mangrove sediment of Sundarban, India

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    Background: Sundarban is the world's largest coastal sediment comprising of mangrove forest which covers about one million hectares in the south-eastern parts of India and southern parts of Bangladesh. The microbial diversity in this sediment is largely unknown till date. In the present study an attempt has been made to understand the microbial diversity in this sediment using a cultivation-independent molecular approach. Results: Two 16 S rRNA gene libraries were constructed and partial sequencing of the selected clones was carried out to identify bacterial strains present in the sediment. Phylogenetic analysis of partially sequenced 16 S rRNA gene sequences revealed the diversity of bacterial strains in the Sundarban sediment. At least 8 different bacterial phyla were detected. The major divisions of detected bacterial phyla were Proteobacteria (alpha, beta, gamma, and delta), Flexibacteria (CFB group), Actinobacteria, Acidobacteria, Chloroflexi, Firmicutes, Planctomycetes and Gammatimonadates. Conclusion: The gammaproteobacteria were found to be the most abundant bacterial group in Sundarban sediment. Many clones showed similarity with previously reported bacterial lineages recovered from various marine sediments. The present study indicates a probable hydrocarbon and oil contamination in this sediment. In the present study, a number of clones were identified that have shown similarity with bacterial clones or isolates responsible for the maintenance of the S-cycle in the saline environment

    Clinical and investigative profile of scrub typhus patients at a tertiary care center in Southern West Bengal, India

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    Background: Scrub typhus, caused by Orientia tsutsugamushi, is an acute febrile illness with symptoms such as fever, chills, and organ failure. The similar clinical presentation in other common diseases such as malaria, dengue fever, and typhoid fever creates difficulty and delay in the clinical diagnosis of scrub typhus. This delay may increase the risk of scrub typhus complications. In India, it is a public health issue with a paucity of data. Aims and Objectives: This study aims to evaluate the clinical characteristics, outcomes, and prognostic factors of patients with scrub typhus. Materials and Methods: This institutional-based observational, cross-sectional study was conducted among consecutively selected 154 adult patients suffering from scrub typhus at a Medical College Hospital situated in the southern part of West Bengal, India. All data were collected according to a pre-designed proforma. At the end of the study, results were analyzed statistically. Results: Younger, females, and homemakers are more susceptible to scrub typhus, mostly in the post-monsoon season from July to November. The incidence of scrub typhus complications is high in the southern part of West Bengal. The case fatality rate of scrub typhus is 6.5%. Male sex, pre-hospitalization duration of illness more than 7 days, presence of diabetes mellitus, serum creatinine (Scr) more than 1.5 mg/dL, serum bilirubin more than 3 mg/dL, systolic blood pressure below 90 mmHg, altered sensorium, and acute respiratory distress syndrome were associated with poor prognosis. Conclusion: A high degree of clinical suspicion is required for the early diagnosis of scrub typhus and the factors associated with poor prognosis must be considered to reduce morbidity and mortality
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