1,721,356 research outputs found
Computational imaging and the fourth Amendment
No full textThesis: S.M. in Technology and Policy, Massachusetts Institute of Technology, Engineering Systems Division, 2015.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Cataloged from student-submitted PDF version of thesis. "This thesis was supervised by Nicholas A. Ashford, Professor of Technology and Policy, School of Engineering, and Ramesh Raskar Associate Professor, Program in Media Arts & Sciences. Ramesh Raskar supervised the technical aspect of chapters 2, 3, and 4"--Page 2.Includes bibliographical references (pages 118-131).Great levels of computational power and new kinds of sensors are being embedded into today's mobile devices. Through computation and new algorithms, the power of these sensors is being harnessed to form full images of scenes around corners and behind walls. This technology has great benefits and can revolutionize human-computer interaction and disaster response, however, it poses interesting questions about privacy and surveillance when anyone with a mobile device, including the police, have the ability to see what was previously invisible. An analysis of federal laws and Supreme Court precedents show that the expectation of privacy test is not appropriate when an advanced imaging technology is in widespread use. The lesson drawn by this thesis is that by establishing legislation that defends privacy as a right, and defines it in a human-centric fashion, regulations can be instated that protect privacy while allowing new technologies to be developed. This thesis addresses computational imaging in the context of privacy in two steps. First, architectures are presented for capturing images around corners using sound, and through walls using Radio-Frequencies (RF). Then, federal laws and relevant court cases are analyzed to show that the legal precedent is unclear in the context of widely-distributed imaging technologies which can see into a space without entering it. Through this analysis, policy recommendations are given for a new regulatory framework which can protect privacy without sacrificing innovation.by Hisham Bedri.S.M. in Technology and Polic
Automated retinal imaging and trend analysis – a tool for health monitoring
Full text linkKarin Roesch, Tristan Swedish, Ramesh Raskar MIT Media Lab, Massachusetts Institute of Technology, Cambridge, MA, USA Abstract: Most current diagnostic devices are expensive, require trained specialists to operate and gather static images with sparse data points. This leads to preventable diseases going undetected until late stage, resulting in greatly narrowed treatment options. This is especially true for retinal imaging. Future solutions are low cost, portable, self-administered by the patient, and capable of providing multiple data points, population analysis, and trending. This enables preventative interventions through mass accessibility, constant monitoring, and predictive modeling. Keywords: next-generation imaging technology, early disease indicators, predictive health assessment, predictive analysis, mass accessibilit
Slow Display
Full text linkAuthors
References
Cited By
Index Terms
Publication
Reviews
Comments
Table of Contents
How can we show our 16 megapixel photos from our latest trip on a digital display? How can we create screens that are visible in direct sunlight as well as complete darkness? How can we create large displays that consume less than 2W of power? How can we create design tools for digital decal application and intuitive-computer aided modeling
Reinterpretable Imager: Towards Variable Post-Capture Space, Angle and Time Resolution in Photography
No full textWe describe a novel multiplexing approach to achieve tradeoffs in space, angle and time resolution in photography. We explore the problem of mapping useful subsets of time-varying 4D lightfields in a single snapshot. Our design is based on using a dynamic mask in the aperture and a static mask close to the sensor. The key idea is to exploit scene-specific redundancy along spatial, angular and temporal dimensions and to provide a programmable or variable resolution tradeoff among these dimensions. This allows a user to reinterpret the single captured photo as either a high spatial resolution image, a refocusable image stack or a video for different parts of the scene in post-processing.
A lightfield camera or a video camera forces a-priori choice in space-angle-time resolution. We demonstrate a single prototype which provides flexible post-capture abilities not possible using either a single-shot lightfield camera or a multi-frame video camera. We show several novel results including digital refocusing on objects moving in depth and capturing multiple facial expressions in a single photo
Simultaneous whole‐animal 3D imaging of neuronal activity using light‐field microscopy
Full text linkNotes: Robert Prevedel*, Young‐Gyu Yoon*, Maximilian Hoffmann, Nikita Pak, Gordon Wetzstein, Saul Kato, Tina Schrödel, Ramesh Raskar, Manuel Zimmer, Edward S Boyden** & Alipasha Vaziri** (* equal contributions, ** co-corresponding authors)High-speed, large-scale three-dimensional (3D) imaging of neuronal activity poses a major challenge in neuroscience. Here we demonstrate simultaneous functional imaging of neuronal activity at single-neuron resolution in an entire Caenorhabditis elegans and in larval zebrafish brain. Our technique captures the dynamics of spiking neurons in volumes of ~700 μm × 700 μm × 200 μm at 20 Hz. Its simplicity makes it an attractive tool for high-speed volumetric calcium imaging
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Correspondence Author:
No full textWe present a novel method to reduce the effect of specularities in digital im-ages. Our approach relies on a simple modification of the capture setup: a multi-flash camera is used to take multiple pictures of the scene, each one with a differ-ently positioned light source. We then formulate the problem of specular highlights reduction as solving a Poisson equation on a gradient field obtained from the in-put images. The obtained specular reduced image is further refined in a matting process with the maximum composite of the input images. Experimental results are demonstrated on real and synthetic images. The entire setup can be conceivably packaged into a self-contained device, no larger than existing digital cameras
- …
