20 research outputs found

    Compression of High-Resolution Satellite Images Using Optical Image Processing

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    This chapter presents a novel method for compressing satellite imagery using phase grating to facilitate the optimization of storage space and bandwidth in satellite communication. In this research work, each Satellite image is first modulated with high grating frequency in a fixed orientation. Due to this modulation, three spots (spectrum) have been generated. From these three spots, by applying Inverse Fourier Transform in any one band, we can recover the image. Out of these three spots, one is center spectrum spot and other spots represent two sidebands. Care should be taken during the spot selection is to avoid aliasing effect. At the receiving end, to recover image we use only one spectrum. We have proved that size of the extracted image is less than the original image. In this way, compression of satellite image has been performed. To measure quality of the output images, PSNR value has been calculated and compared this value with previous techniques. As high-resolution satellite image contains a lot of information, therefore to get detail information from extracted image, compression ratio should be as minimum as possible

    Hierarchical class incremental learning of anatomical structures in fetal echocardiography videos

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    This paper proposes an ultrasound video interpretation algorithm that enables novel classes or instances to be added over time, without significantly affecting prediction abilities on prior representations. The motivating application is fetal echocardiography in midtrimester scans. In this application, a sonographer may acquire multiple video clips of the heart at different points in the full scan. The goal is to make a complete inference of the health of the fetal heart from those multiple clips. To address this scenario, we propose to use an incremental learning approach to build a hierarchical network model that allows for a parallel inclusion of previously unseen anatomical classes without requiring prior data distributions. Super classes are obtained by coarse classification followed by fine classification to allow the model to self-organize anatomical structures in a sequence of categories through a modular architecture. We show that this approach can be adapted with new variable data distributions without significantly affecting previously learned representations. Two extreme situations of new data addition are considered; (1) new class data is available over time with volume and distribution similar to prior available classes, and (2) imbalanced datasets arrive over future time to be learned in a few-shot setting. In either case, availability of data from prior classes is not assumed. Evolution of the learning process is validated using incremental accuracies of fine classification over novel classes and compared to results from an end-to-end transfer learningderived model fine-tuned on a clinical dataset annotated by experienced sonographers. The modularization of subsequent learning reduces the depreciation in future accuracies over old tasks from 6.75% to 1.10% using balanced increments. The depreciation is reduced from 6.95% to 1.89% with imbalanced data distributions in future increments, while retaining competitive classification accuracies in new additions of fine classes with parameter operations in the same order of magnitude in all stages in both cases

    Respondent-specific randomized response technique to estimate sensitive proportion

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    In estimating the proportion of people bearing a stigmatizing characteristic in a community of people, randomized response techniques are plentifully available in the literature. They are implemented essentially using boxes of similar cards of two distinguishable types. In this paper, we propose a more general procedure using five different types of cards. A respondent-specific randomized response technique is also proposed, in which respondents are allowed to build up the boxes according to their own choices. An immediate objective for this change is to enhance, sense of protection of privacy of the respondents. But as by-products, higher efficiency in terms of actual coverage percentages of confidence intervals and related features are demonstrated by a simulation study, and superior jeopardy levels against divulgence of personal secrecy are also reported to be achievable. AMS subject classification: 62D05

    How privacy may be protected in optional randomized response surveys

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    There are materials in literature about how privacy on stigmatizing features like alcoholism, history of tax-evasion, or testing positive in AIDS-related testing may be partially protected by a proper application of randomized response techniques (RRT). The paper demonstrates what amendments are necessary for this approach while applying optional RRTs covering qualitative characteristics, permitting a sampled respondent either to directly reveal sensitive data or choose a randomized response respectively with complementary probabilities. Only a few standard RRTs are illustrated in the text
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