85 research outputs found

    Learning Raw Image Denoising with Bayer Pattern Unification and Bayer Preserving Augmentation

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    In this paper, we present new data pre-processing and augmentation techniques for DNN-based raw image denoising. Compared with traditional RGB image denoising, performing this task on direct camera sensor readings presents new challenges such as how to effectively handle various Bayer patterns from different data sources, and subsequently how to perform valid data augmentation with raw images. To address the first problem, we propose a Bayer pattern unification (BayerUnify) method to unify different Bayer patterns. This allows us to fully utilize a heterogeneous dataset to train a single denoising model instead of training one model for each pattern. Furthermore, while it is essential to augment the dataset to improve model generalization and performance, we discovered that it is error-prone to modify raw images by adapting augmentation methods designed for RGB images. Towards this end, we present a Bayer preserving augmentation (BayerAug) method as an effective approach for raw image augmentation. Combining these data processing technqiues with a modified U-Net, our method achieves a PSNR of 52.11 and a SSIM of 0.9969 in NTIRE 2019 Real Image Denoising Challenge, demonstrating the state-of-the-art performance. Our code is available at https://github.com/Jiaming-Liu/BayerUnifyAug.Comment: Accepted by CVPRW 201

    Cyclosporin A and FK506 Block Induction of the Epstein-Barr Virus Lyric Cycle by Anti-Immunoglobulin

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    AbstractThe Epstein-Barr virus (EBV) BZLF1 gene is expressed early upon induction of the viral lytic cycle and its protein product is unique in its ability to disrupt viral latency in some latently infected cell lines. Anti-immunoglobulin (anti-Ig) treatment of the Burkitt's lymphoma cell line Akata, which bears surface IgG, has previously been shown to synchronously induce transcription of the BZLF1 gene (K. Takada and Y. Ono, 1989, J. Virol. 63, 445-449). We have previously shown that anti-Ig induction of Akata cells activates expression of the tumor necrosis factor alpha (TNF-α) gene via a calcineurin-dependent mechanism (Goldfeld et al., 1992, Proc. Natl. Acad. Sci. USA 89, 12198-12201). Here, we report that anti-Ig induction of the EBV lytic cycle in Akata cells can be blocked by the immunosuppressants cyclosporin A and FK506. Furthermore, we demonstrate that synergistic induction by phorbol ester and calcium ionophore of a BZLF1 promoter-driven reporter construct in an EBV-negative BL cell line can be inhibited by addition of cyclosporin A. Thus, analogous to activation of TNF-α gene in Akata cells, anti-Ig induction of the BZLF1 promoter is most likely mediated by calcineurin and probably involves translocation to the nucleus of a transcription factor sequestered in the cytoplasm. As such, immunosuppressants may be useful probes for dissecting B cell activation pathways involved in regulating EBV gene transcription

    Covariant transport equation and gravito-conductivity in generic stationary spacetimes

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    We find a near detailed balance solution to the relativistic Boltzmann equation under the relaxation time approximation with a collision term which differs from the Anderson–Witting model and is dependent on the stationary observer. Using this new solution, we construct an explicit covariant transport equation for the particle flux in response to the generalized temperature and chemical potential gradients in generic stationary spacetimes, with the transport tensors characterized by some integral functions in the chemical potential and the relativistic coldness. To illustrate the application of the transport equation, we study probe systems in Rindler and Kerr spacetimes and analyze the asymptotic properties of the gravito-conductivity tensor in the near horizon limit. It turns out that both the longitudinal and lateral parts (if present) of the gravito-conductivity tend to be divergent in the near horizon limit. In the weak field limit, our results coincide with the non-relativistic gravitational transport equation which follows from the direct application of the Drude model
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