The Experts below are selected from a list of 534036 Experts worldwide ranked by ideXlab platform
Carsten Rother - One of the best experts on this subject based on the ideXlab platform.
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Depth Super Resolution by Rigid Body Self-Similarity in 3D
2013 IEEE Conference on Computer Vision and Pattern Recognition, 2013Co-Authors: Michael Hornácek, Christoph Rhemann, Margrit Gelautz, Carsten RotherAbstract:We tackle the problem of jointly increasing the spatial resolution and apparent measurement accuracy of an input low-resolution, noisy, and perhaps heavily quantized depth map. In stark contrast to earlier work, we make no use of ancillary data like a color image at the target resolution, multiple aligned depth maps, or a database of high-resolution depth exemplars. Instead, we proceed by identifying and merging patch correspondences within the input depth map itself, exploiting patch wise scene self-similarity across depth such as repetition of geometric primitives or object symmetry. While the notion of 'single-image' super resolution has successfully been applied in the context of color and intensity images, we are to our knowledge the first to present a tailored analogue for depth images. Rather than reason in terms of patches of 2D pixels as others have before us, our key contribution is to proceed by reasoning in terms of patches of 3D points, with matched patch pairs related by a respective 6 DoF rigid body motion in 3D. In support of obtaining a dense correspondence field in reasonable time, we introduce a new 3D variant of Patch Match. A third contribution is a simple, yet effective patch up scaling and merging technique, which predicts sharp object boundaries at the target resolution. We show that our results are highly competitive with those of alternative techniques leveraging even a color image at the target resolution or a database of high-resolution depth exemplars.
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CVPR - Depth Super Resolution by Rigid Body Self-Similarity in 3D
2013 IEEE Conference on Computer Vision and Pattern Recognition, 2013Co-Authors: Michael Hornácek, Christoph Rhemann, Margrit Gelautz, Carsten RotherAbstract:We tackle the problem of jointly increasing the spatial resolution and apparent measurement accuracy of an input low-resolution, noisy, and perhaps heavily quantized depth map. In stark contrast to earlier work, we make no use of ancillary data like a color image at the target resolution, multiple aligned depth maps, or a database of high-resolution depth exemplars. Instead, we proceed by identifying and merging patch correspondences within the input depth map itself, exploiting patch wise scene self-similarity across depth such as repetition of geometric primitives or object symmetry. While the notion of 'single-image' super resolution has successfully been applied in the context of color and intensity images, we are to our knowledge the first to present a tailored analogue for depth images. Rather than reason in terms of patches of 2D pixels as others have before us, our key contribution is to proceed by reasoning in terms of patches of 3D points, with matched patch pairs related by a respective 6 DoF rigid body motion in 3D. In support of obtaining a dense correspondence field in reasonable time, we introduce a new 3D variant of Patch Match. A third contribution is a simple, yet effective patch up scaling and merging technique, which predicts sharp object boundaries at the target resolution. We show that our results are highly competitive with those of alternative techniques leveraging even a color image at the target resolution or a database of high-resolution depth exemplars.
Julian Bonnerjea - One of the best experts on this subject based on the ideXlab platform.
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Scale-up of monoclonal antibody purification processes
Journal of Chromatography B, 2007Co-Authors: Suzanne Aldington, Julian BonnerjeaAbstract:Mammalian cell culture technology has improved so rapidly over the last few years that it is now commonplace to produce multi-kilogram quantities of therapeutic monoclonal antibodies in a single batch. Purification processes need to be scaled-up to match the improved upstream productivity. In this chapter key practical issues and approaches to the scale-up of monoclonal antibody purification processes are discussed. Specific purification operations are addressed including buffer preparation, chromatography column sizing, aggregate removal, filtration and volume handling with examples given.
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Scale-up of monoclonal antibody purification processes
Journal of Chromatography B: Analytical Technologies in the Biomedical and Life Sciences, 2007Co-Authors: Suzanne Aldington, Julian BonnerjeaAbstract:Mammalian cell culture technology has improved so rapidly over the last few years that it is now commonplace to produce multi-kilogram quantities of therapeutic monoclonal antibodies in a single batch. Purification processes need to be scaled-up to match the improved upstream productivity. In this chapter key practical issues and approaches to the scale-up of monoclonal antibody purification processes are discussed. Specific purification operations are addressed including buffer preparation, chromatography column sizing, aggregate removal, filtration and volume handling with examples given. © 2006 Elsevier B.V. All rights reserved.
Florence Tupin - One of the best experts on this subject based on the ideXlab platform.
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Patch similarity under non Gaussian noise
2016Co-Authors: Charles-alban Deledalle, Florence Tupin, Loïc DenisAbstract:Many tasks in computer vision require to match image parts. While higher-level methods consider image features such as edges or robust descriptors, low-level approaches compare groups of pixels (patches) and provide dense matching. Patch similarity is a key ingredient to many techniques for image registration, stereo-vision, change detection or denoising. A fundamental difficulty when comparing two patches from "real" data is to decide whether the differences should be ascribed to noise or intrinsic dissimilarity. Gaussian noise assumption leads to the classical definition of patch similarity based on the squared intensity differences. When the noise departs from the Gaussian distribution, several similarity criteria have been proposed in the literature. We review seven of those criteria taken from the fields of image processing, detection theory and machine learning. We discuss their theoretical grounding and provide a numerical comparison of their performance under Gamma and Poisson noises.
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How to compare noisy patches? Patch similarity beyond Gaussian noise
International Journal of Computer Vision, 2015Co-Authors: Charles-alban Deledalle, Loïc Denis, Florence TupinAbstract:Many tasks in computer vision require to match image parts. While higher-level methods consider image features such as edges or robust descriptors, low-level approaches (so-called image-based) compare groups of pixels (patches) and provide dense matching. Patch similarity is a key ingredient to many techniques for image registration, stereo-vision, change detection or denoising. Recent progress in natural image modeling also makes intensive use of patch comparison. A fundamental difficulty when comparing two patches from "real" data is to decide whether the differences should be ascribed to noise or intrinsic dissimilarity. Gaussian noise assumption leads to the classical definition of patch similarity based on the squared differences of intensities. For the case where noise departs from the Gaussian distribution, several similarity criteria have been proposed in the literature of image processing, detection theory and machine learning. By expressing patch (dis)similarity as a detection test under a given noise model, we introduce these criteria with a new one and discuss their properties. We then assess their performance for different tasks: patch discrimination, image denoising, stereo-matching and motion-tracking under gamma and Poisson noises. The proposed criterion based on the generalized likelihood ratio is shown to be both easy to derive and powerful in these diverse applications.
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Modeling the distribution of patches with shift-invariance: Application to SAR image restoration
2014 IEEE International Conference on Image Processing (ICIP), 2014Co-Authors: Sonia Tabti, Loïc Denis, Charles-alban Deledalle, Florence TupinAbstract:Patches have proven to be very effective features to model natural images and to design image restoration methods. Given the huge diversity of patches found in images, modeling the distribution of patches is a difficult task. Rather than attempting to accurately model all patches of the image, we advocate that it is sufficient that all pixels of the image belong to at least one well-explained patch. An image is thus described as a tiling of patches that have large prior probability. In contrast to most patch-based approaches, we do not process the image in patch space, and consider instead that patches should match well everywhere where they overlap. In-order to apply this modeling to the restoration of SAR images, we define a suitable data-fitting term to account for the statistical distribution of speckle. Restoration results are competitive with state-of-the art SAR despeckling methods.
Michael Hornácek - One of the best experts on this subject based on the ideXlab platform.
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Depth Super Resolution by Rigid Body Self-Similarity in 3D
2013 IEEE Conference on Computer Vision and Pattern Recognition, 2013Co-Authors: Michael Hornácek, Christoph Rhemann, Margrit Gelautz, Carsten RotherAbstract:We tackle the problem of jointly increasing the spatial resolution and apparent measurement accuracy of an input low-resolution, noisy, and perhaps heavily quantized depth map. In stark contrast to earlier work, we make no use of ancillary data like a color image at the target resolution, multiple aligned depth maps, or a database of high-resolution depth exemplars. Instead, we proceed by identifying and merging patch correspondences within the input depth map itself, exploiting patch wise scene self-similarity across depth such as repetition of geometric primitives or object symmetry. While the notion of 'single-image' super resolution has successfully been applied in the context of color and intensity images, we are to our knowledge the first to present a tailored analogue for depth images. Rather than reason in terms of patches of 2D pixels as others have before us, our key contribution is to proceed by reasoning in terms of patches of 3D points, with matched patch pairs related by a respective 6 DoF rigid body motion in 3D. In support of obtaining a dense correspondence field in reasonable time, we introduce a new 3D variant of Patch Match. A third contribution is a simple, yet effective patch up scaling and merging technique, which predicts sharp object boundaries at the target resolution. We show that our results are highly competitive with those of alternative techniques leveraging even a color image at the target resolution or a database of high-resolution depth exemplars.
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CVPR - Depth Super Resolution by Rigid Body Self-Similarity in 3D
2013 IEEE Conference on Computer Vision and Pattern Recognition, 2013Co-Authors: Michael Hornácek, Christoph Rhemann, Margrit Gelautz, Carsten RotherAbstract:We tackle the problem of jointly increasing the spatial resolution and apparent measurement accuracy of an input low-resolution, noisy, and perhaps heavily quantized depth map. In stark contrast to earlier work, we make no use of ancillary data like a color image at the target resolution, multiple aligned depth maps, or a database of high-resolution depth exemplars. Instead, we proceed by identifying and merging patch correspondences within the input depth map itself, exploiting patch wise scene self-similarity across depth such as repetition of geometric primitives or object symmetry. While the notion of 'single-image' super resolution has successfully been applied in the context of color and intensity images, we are to our knowledge the first to present a tailored analogue for depth images. Rather than reason in terms of patches of 2D pixels as others have before us, our key contribution is to proceed by reasoning in terms of patches of 3D points, with matched patch pairs related by a respective 6 DoF rigid body motion in 3D. In support of obtaining a dense correspondence field in reasonable time, we introduce a new 3D variant of Patch Match. A third contribution is a simple, yet effective patch up scaling and merging technique, which predicts sharp object boundaries at the target resolution. We show that our results are highly competitive with those of alternative techniques leveraging even a color image at the target resolution or a database of high-resolution depth exemplars.
Ekambir Sidhu - One of the best experts on this subject based on the ideXlab platform.
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Performance evaluation of microstrip patch antenna using plywood as substrate for fixed satellite and earth exploration applications
2017 International Conference On Smart Technologies For Smart Nation (SmartTechCon), 2017Co-Authors: Parshant Rawat, Divesh Mittal, Mayank Sharma, Bhavneet Kaur, Damanpreet Singh, Ekambir SidhuAbstract:A rectangular microstrip patch antenna employing wood as substrate has been propounded in this paper. A piece of wood having the dielectric constant of εr=4.1 and thickness of 4.8 mm has been designed as the dielectric material between the radiating patch and ground. The copper having thickness of 0.25 mm has been used for the purpose of designing the patch, ground and feed line. Various feeding techniques has been used to feed the microstrip patch antenna and width of feed line has been set nearly across 50 Ω for impedance matching and minimum reflection losses. Various antenna characteristics like gain (dB), directivity (dBi), HPBW, return loss (dB), impedance (ohms) has been analyzed and the value of VSWR should be less than 2 corresponding to its resonant frequency which is the maximum acceptable value of VSWR. CST Microwave Studio 2016 has been used for the simulation of antenna delineation. E5071C Network Analyzer and Anechoic Chamber has been used for the pragmatically fabrication and testing of propounded antenna. It has been analyzed that simulated results closely match with pragmatic result.
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Performance analysis of microstrip patch antenna using CSRR and PSRR techniques for WLAN, WiMAX, Wi-Fi and IMT applications
2016 International Conference on Wireless Communications Signal Processing and Networking (WiSPNET), 2016Co-Authors: Divesh Mittal, Avneet Kaur, Lovepreet Singh, Ashish Sharma, Ekambir SidhuAbstract:This paper demonstrates the performance analysis of different CSRR and PSRR techniques in microstrip patch antenna design. In this paper, the performance of conventional rectangular microstrip patch antenna with defected ground structure has been analysed by employing different complementary split-ring resonator (rectangular and circular shape) and planar split-ring resonator (M and mho shape) structures on the patch of antenna. It has been observed that there is significant improvement in impedance bandwidth and return loss by employing different CSRR and PSRR structures on conventional microstrip patch antenna. The proposed antennas have been designed and simulated in CST-Microwave Studio 2014. The performance of antenna designs has been analysed in terms of return loss (S11), impedance bandwidth, gain, directivity and VSWR. It has been concluded that rectangular CSRR leads to drastic improvement in return loss and M shaped PSRR leads to improvement in gain, directivity and impedance bandwidth of antenna. These antenna designs have been fabricated and tested practically using E5071C network analyser and anechoic chamber. It has been concluded that the practical results closely match with the simulated results. The proposed antennas can be used for WLAN, Wi-MAX, Wi-Fi and IMT applications.
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High gain substrate slotted microstrip patch antenna design for X-band satellite uplink applications
2016 Progress in Electromagnetic Research Symposium (PIERS), 2016Co-Authors: Divesh Mittal, Avneet Kaur, Maninder Singh, Raveena Bhatoa, Anshula Garg, Ekambir SidhuAbstract:This paper presents high gain substrate slotted microstrip patch antenna design for X-band satellite applications. The proposed antenna has been designed by using the substrate of Flame Retardant 4 (FR4) having dielectric constant εr of 4.4. The ground, patch and the feedline are made of copper material having thickness of 0.02mm and conductivity of 5.58 × 106 Siemens/m. The proposed antenna has been fed through microstrip feedline via impedance transformer. The impedance transformer has been used to match the impedance of proposed antenna to 50Ω impedance of the SMA connector used to feed power to the designed antenna. The proposed antenna has been designed and simulated using CST Microwave Studio 2014. The proposed antenna covers the X-band satellite uplink (7.9 GHz-8.4 GHz) frequency band making it suitable to be employed for satellite communication applications. Apart, the proposed antenna finds its applications in indoor location and RFID tag (tracking equipment) applications. The simulated antenna design has been practically fabricated and tested by using Network Analyser E5071C and anechoic chamber. It has been observed that the practical results closely match with the simulated antenna results, thus signifying that the proposed antenna design can be feasibly employed for proposed applications.
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High directivity FR4 substrate slotted defected ground microstrip patch antenna for X-band applications
2016 International Conference on Global Trends in Signal Processing Information Computing and Communication (ICGTSPICC), 2016Co-Authors: Divesh Mittal, Avneet Kaur, Aman Nag, Ekambir SidhuAbstract:The paper emphasizes on the design and performance analysis of high directivity FR4 substrate slotted defected ground microstrip patch antenna for X-Band applications. The antenna has been fed by microstrip feedline via impedance transformer to match the impedance of proposed antenna with the 50Ω impedance of co-axial connector used for feeding power to the antenna. The propounded antenna has been devised and simulated in CST Microwave Studio 2014. This antenna resonates at frequency of 7.94 GHz with the minimal return loss of -81.25 dB, high gain of 8.5 dB and directivity of 8.12 dBi. The proposed antenna has been designed using Flame Retardant 4 (FR4) substrate of dielectric constant, εr=4.4 sandwiched between copper patch and ground plane. The designed antenna has compact area and operating bandwidth of 560 MHz (7.67 GHz-8.22 GHz). The designed antenna can be suitably employed for X-band applications-military, satellite to earth downlink, earth to satellite uplink, radio determination and ultra-wide band applications. The antenna has been fabricated and efficaciously tested using E5071C network analyser and anechoic chamber. It has been perceived that the practical results match with the simulated results.
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Novel dual circular stacked microstrip patch antenna design for S-band UWB applications
2016 International Conference on Control Computing Communication and Materials (ICCCCM), 2016Co-Authors: Aman Nag, Divesh Mittal, Avneet Kaur, Ekambir SidhuAbstract:In this paper, the design and performance analysis of dual circular stacked microstrip patch antenna for S-band applications has been proposed. In the proposed antenna design, the substrate of material FR 4 having dielectric constant 4.4 have been used. The ground, patch and feedline are of copper material. The proposed antenna has two circular stackings on the patch and the antenna has impedance bandwidth of 110 MHz with operating frequency ranging from 3.34 GHz to 3.45 GHz. In the proposed antenna design, the stacking has been employed to enhance the directivity and return loss. The proposed antenna design has been fed by microstrip feedline having impedance of 49.36 Ω. The performance of antenna has been analyzed in terms of return loss (dB), impedance bandwidth (MHz), directivity (dBi), gain (dB), VSWR and impedance (ohms). The proposed antenna design resonates at 3.40 GHz frequency with minimum return loss of -41.55 dB, gain of 4.45 dB and directivity of 6.47 dBi. The proposed antenna can be used for S-band (2GHz-4 GHz) applications. The proposed antenna has been designed and simulated using CST Microwave Studio 2014. The proposed antenna has been successfully fabricated and tested using E5071C network analyzer and anechoic chamber. It has been observed that the CST simulated antenna results closely match with the practically fabricated results of the proposed antenna.
