CiteULike: Tag blind

Focus Area Extraction by Blind Deconvolution for Defining Regions of Interest

Levente Kovacs — 2007-04-27T11:47:37-00:00

Pattern Analysis and Machine Intelligence, IEEE Transactions on, Vol. 29, No. 6. (2007), pp. 1080-1085.

We present an automatic focus area estimation method, working with a single image without a priori information about the image, the camera, or the scene. It produces relative focus maps by localized blind deconvolution and a new residual error-based classification. Evaluation and comparison is performed and applicability is shown through image indexing.

Blind deconvolution through digital signal processing

TG Stockham — 2005-07-28T14:10:33-00:00

Proceedings of the IEEE, Vol. 63, No. 4. (1975), pp. 678-692.

This paper addresses the problem of deconvolving two signals when both are unknown. The authors call this problem blind deconvolution. The discussion develops two related solutions which can be applied through digital signal processing in certain practical cases. The case of reverberated and resonated sound forms the center of the development. The specific problem of restoring old acoustic recordings provides an experimental test. The important effects of noise and non-stationary signals lead to the detailed part of the presentation. In addition, the paper presents results for the case of images degraded by some common forms of blur.

The challenge of information visualization evaluation

Catherine Plaisant — 2005-02-22T22:19:19-00:00

(2004), pp. 109-116.

Hand movements: a window into haptic object recognition.

SJ Lederman — 2006-12-09T19:37:34-00:00

Cognit Psychol, Vol. 19, No. 3. (July 1987), pp. 342-368.

Comparing Methods for Introducing Blind and Visually Impaired People to Unfamiliar Urban Environments

Angeles Espinosa — 2005-11-11T14:08:49-00:00

Journal of Environmental Psychology, Vol. 18, No. 3. (September 1998), pp. 277-287.

This paper reports two experiments which compared the effectiveness of different methods for introducing blind and visually impaired people to the spatial layout of urban environments. In Experiment 1, 30 blind and visually impaired adults learnt a long and complex route through an area of central Madrid (Spain) either by direct experience or by a combination of direct experience and a tactile map or a combination of direct experience and a verbal description of the area. Performance on measures of practical spatial knowledge and of representational spatial knowledge was significantly better in participants in the tactile map condition. In Experiment 2, participants learnt a similar route in an area of Sheffield (Britain) using either just a tactile map or by direct experience. No significant difference was found between the two conditions using the same measures as in Experiment 1.

Blind Deconvolution

JA Cadzow — 2008-03-05T18:35:32-00:00

Digital Signal Processing, Vol. 5, No. 1. (January 1995), pp. 3-20.

The ability to implement deconvolution in a numerically stable fashion is essential in many applications. In blind deconvolution it is required to identify the excitation of a linear system using observations made on the associated system response in which no knowledge of the linear system is presumed. A solution to the blind deconvolution problem is herein presented that is based on maximizing the magnitude of the excitation estimate's kurtosis. Conditions under which this excitation estimate is equal to a scaled and time-shifted version of the actual excitation are provided. Furthermore, an effective algorithm for achieving the kurtosis magnitude maximization is developed. This blind deconvolution algorithm is different from other kurtosis type algorithms in that it: (i) is applicable to a larger class of excitations, (ii) imposes no constraints on the linear system's dynamics, and, (iii) requires no nuisance parameters entailing preknowledge of the excitation's statistics. The utility of this algorithm is illustrated by a number of examples.

Achieving web accessibility

Brian Sierkowski — 2005-03-29T21:18:36-00:00

(2002), pp. 288-291.

Understanding concurrent earcons: Applying auditory scene analysis principles to concurrent earcon recognition

David Mcgookin — 2005-03-29T21:17:06-00:00

ACM Trans. Appl. Percept., Vol. 1, No. 2. (October 2004), pp. 130-155.

A Web navigation tool for the blind

Mary Zajicek — 2005-03-29T21:15:12-00:00

(1998), pp. 204-206.

Planning, reasoning, and agents for non-visual navigation of tables and frames

Enrico Pontelli — 2005-03-29T21:14:00-00:00

(2002), pp. 73-80.

Opening the eyes of those who can see to the world of those who can't: a case study

Susan Harrison — 2005-03-29T21:06:57-00:00

(2005), pp. 22-26.

Why make websites accessible?: and how?

Katy Whitelaw — 2005-03-29T21:05:08-00:00

(2003), pp. 259-261.

A domain specific language framework for non-visual browsing of complex HTML structures

E Pontelli — 2005-03-29T21:03:47-00:00

(2000), pp. 180-187.

Semantic bookmarking for non-visual web access

Saikat Mukherjee — 2005-03-29T21:01:16-00:00

(2004), pp. 185-192.

Rendering tables in audio: the interaction of structure and reading styles

Yeliz Yesilada — 2005-03-29T20:59:56-00:00

(2004), pp. 16-23.

Accessibility of Internet websites through time

Stephanie Hackett — 2005-03-29T20:59:01-00:00

(2004), pp. 32-39.

Tension, what tension?: Website accessibility and visual design

Helen Petrie — 2005-03-29T20:57:22-00:00

(2004), pp. 13-18.

Look ma, no mouse!

Jakub Segen — 2005-03-29T20:55:27-00:00

Commun. ACM, Vol. 43, No. 7. (July 2000), pp. 102-109.

Search result exploration: a preliminary study of blind and sighted users' decision making and performance

Melody Ivory — 2005-03-29T20:53:58-00:00

(2004), pp. 1453-1456.

Nonvisual tool for navigating hierarchical structures

Ann Smith — 2005-03-29T20:52:54-00:00

(2004), pp. 133-139.

Hearsay: enabling audio browsing on hypertext content

IV Ramakrishnan — 2005-03-29T20:51:08-00:00

(2004), pp. 80-89.

Evaluating web resources for disability access

Murray Rowan — 2005-03-29T20:49:41-00:00

(2000), pp. 80-84.

The design of auditory user interfaces for blind users

Hilko Donker — 2005-03-29T20:46:19-00:00

(2002), pp. 149-156.

Usability testing with screen reading technology in a Windows environment

Kitch Barnicle — 2005-03-29T20:44:10-00:00

(2000), pp. 102-109.

Accessibility designer: visualizing usability for the blind

Hironobu Takagi — 2005-03-29T20:42:47-00:00

(2004), pp. 177-184.

Designing search engine user interfaces for the visually impaired

Barbara Leporini — 2005-03-29T20:39:52-00:00

(2004), pp. 57-66.

Use of haptic device by blind and sighted people: perception of virtual textures and objects

C Colwell — 2008-02-09T09:51:47-00:00

(1998)

This paper describes a series of studies involving a haptic device which can display virtual textures and 3D objects. The device has potential for simulating real world objects and assisting in the navigation of virtual environments (VEs). Three experiments investigated: (a) whether previous results from experiments using real textures could be replicated using virtual textures

Text formats and web design for visually impaired and dyslexic readers--Clear Text for All

Lindsay Evett — 2006-07-08T20:38:01-00:00

Interacting with Computers, Vol. 17, No. 4. (July 2005), pp. 453-472.

The Royal National Institute of the Blind (RNIB) has produced a Clear Print booklet, which contains recommendations for the production of Clear Print for the blind and partially sighted. The British Dyslexia Association (BDA) has produced a Dyslexia Style Guide, which covers similar issues. Both focus on producing text, which is clear and therefore more easily read, and there is significant overlap between the two. By comparing the two, a set of specifications for the production of text has been generated. Using the specifications should produce clear text for both dyslexic and visually impaired readers. It should improve readability for all. The text specifications plus additional recommendations from the BDA are considered with respect to an existing set of web site design guidelines for dyslexic readers to produce an enhanced set of guidelines compatible with both. These guidelines are recommended to be followed as standard, both for their benefits to visually impaired and dyslexic readers, promoting accessibility for these groups, and for their potential to improve accessibility for all.

Is Love Blind? The Effects of Experience and Infatuation on the Perception of Love: Interpersonal Sensitivity, Part II

Maya Aloni — 2004-12-28T16:47:05-00:00

Journal of Nonverbal Behavior, Vol. 28, No. 4., 287.

Detection of pedestrian crossings with projective invariants from image data

Tadayoshi Shioyama — 2004-12-28T16:27:50-00:00

Measurement Science and Technology, Vol. 15, No. 12., 2400.

A Secure Three-Move Blind Signature Scheme for Polynomially Many Signatures

Masayuki Abe — 2008-08-15T09:38:02-00:00

Advances in Cryptology — EUROCRYPT 2001 (2001), pp. 136-151.

Known practical blind signature schemes whose security against adaptive and parallel attacks can be proven in the random oracle model either need five data exchanges between the signer and the user or are limited to issue only logarithmically many signatures in terms of a security parameter. This paper presents an efficient blind signature scheme that allows a polynomial number of signatures to be securely issued while only three data exchanges are needed. Its security is proven in the random oracle model. As an application, a provably secure solution for double-spender-traceable e-cash is presented.at]

Security of Blind Digital Signatures

Ari Juels — 2008-08-05T05:59:43-00:00

Advances in Cryptology - CRYPTO '97: 17th Annual International Cryptology Conference, Santa Barbara, California, USA, August 1997. Proceedings (1997), 150.

Blind digital signatures were introduced by Chaum. In this paper, we show how security and blindness properties for blind digital signatures, can be simultaneously defined and satisfied, assuming an arbitrary one-way trapdoor permutation family. Thus, this paper presents the first complexity-based proof of security for blind signatures.

Efficient Quantum-immune Blind Signatures

Markus Rückert — 2008-08-04T05:58:24-00:00

(25 Jul 2008)

We present an idea for the the first quantum-immune blind signature scheme. Our scheme is provably secure, efficient, and round-optimal.

Provably Secure air Blind Signatures with Tight Revocation

Masayuki Abe — 2008-08-05T05:51:06-00:00

Advances in Cryptology — ASIACRYPT 2001 (2001), pp. 583-601.

A fair blind signature scheme allows the trustee to revoke blindness so that it provides authenticity and anonymity to honest users while preventing malicious users from abusing the anonymity to conduct blackmail etc. Although plausible constructions that offer efficient tricks for anonymity revocation have been published, security, especially one-more unforgeability and revocability against adaptive and parallel attacks, has not been studied well. We point out a concrete vulnerability of some of the previous schemes and present an efficient fair blind signature scheme with a security proof against most general attacks. Our scheme offers tight revocation where each signature and issuing session can be linked by the trustee.

Provably Secure Partially Blind Signatures

Masayuki Abe — 2008-08-05T05:49:06-00:00

Advances in Cryptology — CRYPTO 2000 (2000), pp. 271-286.

Partially blind signature schemes are an extension of blind signature schemes that allow a signer to explicitly include necessary information (expiration date, collateral conditions, or whatever) in the resulting signatures under some agreement with the receiver. This paper formalizes such a notion and presents secure and efficient schemes based on a widely applicable method of obtaining witness indistinguishable protocols. We then give a formal proof of security in the random oracle model. Our approach also allows one to construct secure fully blind signature schemes based on a variety of signature schemes.

Concurrently-Secure Blind Signatures Without Random Oracles or Setup Assumptions

Carmit Hazay — 2008-08-05T08:51:33-00:00

Theory of Cryptography (2007), pp. 323-341.

We show a new protocol for blind signatures in which security is preserved even under arbitrarily-many concurrent executions. The protocol can be based on standard cryptographic assumptions and is the first to be proven secure in a concurrent setting (under any assumptions) without random oracles or a trusted setup assumption such as a common reference string. Along the way, we also introduce new definitions of security for blind signature schemes.

Efficient Blind and Partially Blind Signatures Without Random Oracles

Tatsuaki Okamoto — 2008-08-05T06:48:08-00:00

Theory of Cryptography (2006), pp. 80-99.

This paper proposes a new efficient signature scheme from bilinear maps that is secure in the standard model (i.e., without the random oracle model). Our signature scheme is more effective in many applications (e.g., blind signatures, group signatures, anonymous credentials etc.) than the existing secure signature schemes in the standard model such as the Boneh-Boyen [6], Camenisch-Lysyanskaya [10], Cramer-Shoup [15] and Waters [33] schemes (and their variants). The security proof of our scheme requires a slightly stronger assumption, the 2SDH assumption, than the SDH assumption used by Boneh-Boyen. As typical applications of our signature scheme, this paper presents efficient blind signatures and partially blind signatures that are secure in the standard model. Here, partially blind signatures are a generalization of blind signatures (i.e., blind signatures are a special case of partially blind signatures) and have many applications including electronic cash and voting. Our blind signature scheme is much more efficient than the existing secure blind signature schemes in the standard model such as the Camenisch-Koprowski-Warinsch [8] and Juels-Luby-Ostrovsky [22] schemes, and is also almost as efficient as the most efficient blind signature schemes whose security has been analyzed heuristically or in the random oracle model. Our partially blind signature scheme is the first one that is secure in the standard model and it is very efficient (almost as efficient as our blind signatures). We also present a blind signature scheme based on the Waters signature scheme.

AcceSS: accessibility through simplification & summarization

Bambang Parmanto — 2007-10-03T10:44:29-00:00

(2005), pp. 18-25.

Accessibility Transformation Gateway

Bambang Parmanto — 2008-06-11T13:10:55-00:00

(2005)

Combining haptic and braille technologies: design issues and pilot study

Christophe Ramstein — 2006-06-13T19:18:00-00:00

(1996), pp. 37-44.

A pocket-PC based navigational aid for blind individuals

MH Choudhury — 2008-05-15T09:26:56-00:00

Virtual Environments, Human-Computer Interfaces and Measurement Systems, 2004. (VECIMS). 2004 IEEE Symposium on (2004), pp. 43-48.

This paper describes a pocket-PC based electronic travel aid (ETA) that helps a blind individual navigate through indoor environments. The system detects surrounding obstacles using ultrasonic range sensors and the travel direction using an electronic compass. The acquired information is processed by a pocket-PC to generate a virtual acoustic environment where nearby obstacles are recognizable to the user. This virtual environment is played back through stereo headphones, so that the user can perceive surrounding obstacles and the direction of the Earth's magnetic North, using spatialized 3D sounds. The paper describes the instrumental and computational aspects of the design and presents the results, demonstrating the improvement in blind travel achieved with the system.

Whole brain functional connectivity in the early blind.

Y Liu — 2007-11-25T14:52:04-00:00

Brain, Vol. 130, No. Pt 8. (August 2007), pp. 2085-2096.

Early visual deprivation can lead to changes in the brain, which may be explained by either of two hypotheses. The general loss hypothesis has been proposed to explain maladjustments, while the compensatory plasticity hypothesis may explain a superior ability in the use of the remaining senses. Most previous task-based functional MRI (fMRI) studies have supported the compensatory plasticity hypothesis, but it has been difficult to provide evidence to support the general loss hypothesis, since the blind cannot execute visual tasks. The study of resting state fMRI data may provide an opportunity to simultaneously detect the two aspects of changes in the blind. In this study, using a whole brain perspective, we investigated the decreased and increased functional connectivities in the early blind using resting state fMRI data. The altered functional connectivities were identified by comparing the correlation coefficients of each pair of brain regions of 16 early blind subjects (9 males; age range: 15.6-29.3 years, mean age: 22.1 years) with the corresponding coefficients of gender- and age-matched sighted volunteers. Compared with the sighted subjects, the blind demonstrated the decreased functional connectivities within the occipital visual cortices as well as between the occipital visual cortices and the parietal somatosensory, frontal motor and temporal multisensory cortices. Such differences may support the general loss hypothesis. However, we also found that the introduction of Braille earlier in life and for longer daily practice times produced stronger functional connectivities between these brain areas. These findings may support the compensatory plasticity hypothesis. Additionally, we found several increased functional connectivities between the occipital cortices and frontal language cortices in those with early onset of blindness, which indicate the predominance of compensatory plasticity. Our findings indicate that changes in the functional connectivities in the resting state may be an integrated reflection of general loss and compensatory plasticity when a single sensory modality is deprived.

The plastic human brain cortex.

A Pascual-Leone — 2005-11-27T02:05:08-00:00

Annu Rev Neurosci, Vol. 28 (2005), pp. 377-401.

Plasticity is an intrinsic property of the human brain and represents evolution's invention to enable the nervous system to escape the restrictions of its own genome and thus adapt to environmental pressures, physiologic changes, and experiences. Dynamic shifts in the strength of preexisting connections across distributed neural networks, changes in task-related cortico-cortical and cortico-subcortical coherence and modifications of the mapping between behavior and neural activity take place in response to changes in afferent input or efferent demand. Such rapid, ongoing changes may be followed by the establishment of new connections through dendritic growth and arborization. However, they harbor the danger that the evolving pattern of neural activation may in itself lead to abnormal behavior. Plasticity is the mechanism for development and learning, as much as a cause of pathology. The challenge we face is to learn enough about the mechanisms of plasticity to modulate them to achieve the best behavioral outcome for a given subject.

Blind deconvolution of images using optimal sparse representations

MM Bronstein — 2006-04-01T01:51:59-00:00

Image Processing, IEEE Transactions on, Vol. 14, No. 6. (2005), pp. 726-736.

The relative Newton algorithm, previously proposed for quasi-maximum likelihood blind source separation and blind deconvolution of one-dimensional signals is generalized for blind deconvolution of images. Smooth approximation of the absolute value is used as the nonlinear term for sparse sources. In addition, we propose a method of sparsification, which allows blind deconvolution of arbitrary sources, and show how to find optimal sparsifying transformations by supervised learning.

Relative optimization for blind deconvolution

AM Bronstein — 2006-04-01T01:51:15-00:00

Signal Processing, IEEE Transactions on [see also Acoustics, Speech, and Signal Processing, IEEE Transactions on], Vol. 53, No. 6. (2005), pp. 2018-2026.

We propose a relative optimization framework for quasi-maximum likelihood (QML) blind deconvolution and the relative Newton method as its particular instance. Special Hessian structure allows fast Newton system construction and solution, resulting in a fast-convergent algorithm with iteration complexity comparable to that of gradient methods. We also propose the use of rational infinite impulse response (IIR) restoration kernels, which constitute a richer family of filters than the traditionally used finite impulse response (FIR) kernels. We discuss different choices of nonlinear functions that are suitable for deconvolution of super- and sub-Gaussian sources and formulate the conditions under which the QML estimation is stable. Simulation results demonstrate the efficiency of the proposed methods.

Blind deconvolution via cumulant extrema

JA Cadzow — 2006-03-29T20:44:38-00:00

Signal Processing Magazine, IEEE, Vol. 13, No. 3. (1996), pp. 24-42.

Classical deconvolution is concerned with the task of recovering an excitation signal, given the response of a known time-invariant linear operator to that excitation. Deconvolution is discussed along with its more challenging counterpart, blind deconvolution, where no knowledge of the linear operator is assumed. This discussion focuses on a class of deconvolution algorithms based on higher-order statistics, and more particularly, cumulants. These algorithms offer the potential of superior performance in both the noise free and noisy data cases relative to that achieved by other deconvolution techniques. This article provides a tutorial description as well as presenting new results on many of the fundamental higher-order concepts used in deconvolution, with the emphasis on maximizing the deconvolved signal's normalized cumulant

Blind Separation of Superimposed Shifted Images Using Parameterized Joint Diagonalization

Efrat Be'ery — 2008-02-28T04:12:51-00:00

IEEE Transactions on Image Processing, Vol. 17, No. 3. (March 2008), pp. 340-353.

We consider the blind separation of source images from linear mixtures thereof, involving different relative spatial shifts of the sources in each mixture. Such mixtures can be caused, e.g., by the presence of a semi-reflective medium (such as a window glass) across a photographed scene, due to slight movements of the medium (or of the sources) between snapshots. Classical separation approaches assume either a static mixture model or a fully convolutive mixture model, which are, respectively, either under- or over-parameterized for this problem. In this paper, we develop a specially parameterized scheme for approximate joint diagonalization of estimated spectrum matrices, aimed at estimating the succinct set of mixture parameters: the static (gain) coefficients and the shift values. The estimated parameters are, in turn, used for convenient frequency-domain separation. As we demonstrate using both synthetic mixtures and real-life photographs, the advantage of the ability to incorporate spatial shifts is twofold: Not only does it enable separation when such shifts are present, but it also warrants deliberate introduction of such shifts as a simple source of added diversity whenever the static mixing coefficients form a singular matrix -- thereby enabling separation in otherwise inseparable scenes.

Space-Variant Restoration of Images Degraded by Camera Motion Blur

Michal Sorel — 2008-02-14T10:33:17-00:00

IEEE Transactions on Image Processing, Vol. 17, No. 2. (February 2008), pp. 105-116.

We examine the problem of restoration from multiple images degraded by camera motion blur. We consider scenes with significant depth variations resulting in space-variant blur. The proposed algorithm can be applied if the camera moves along an arbitrary curve parallel to the image plane, without any rotations. The knowledge of camera trajectory and camera parameters is not necessary. At the input, the user selects a region where depth variations are negligible. The algorithm belongs to the group of variational methods that estimate simultaneously a sharp image and a depth map, based on the minimization of a cost functional. To initialize the minimization, it uses an auxiliary window-based depth estimation algorithm. Feasibility of the algorithm is demonstrated by three experiments with real images.

Watermarking Digital 3-D Volumes in the Discrete Fourier Transform Domain

Vassilios Solachidis — 2008-02-15T07:44:06-00:00

IEEE Transactions on Multimedia, Vol. 9, No. 7. (November 2007), pp. 1373-1383.

In this paper, a robust blind watermarking method for 3-D volumes is presented. A bivalued watermark is embedded in the Fourier transform magnitude of the 3-D volume. The Fourier domain has been selected because of its scaling and rotation invariance. Furthermore, in order to decrease the detection time, a special symmetry of the watermark is exploited. The proposed method is proven to be resistant to 3-D lowpass filtering, noise addition, scaling, translation, cropping and rotation. Experimental results prove the robustness of this method against the above-mentioned attacks.

`Print and Scan' Resilient Data Hiding in Images

Kaushal Solanki — 2007-02-28T17:12:24-00:00

IEEE Transactions on Information Forensics and Security, Vol. 1, No. 4. (December 2006), pp. 464-478.

Print-scan resilient data hiding finds important applications in document security and image copyright protection. This paper proposes methods to hide information into images that achieve robustness against printing and scanning with blind decoding. The selective embedding in low frequencies scheme hides information in the magnitude of selected low-frequency discrete Fourier transform coefficients. The differential quantization index modulation scheme embeds information in the phase spectrum of images by quantizing the difference in phase of adjacent frequency locations. A significant contribution of this paper is analytical and experimental modeling of the print-scan process, which forms the basis of the proposed embedding schemes. A novel approach for estimating the rotation undergone by the image during the scanning process is also proposed, which specifically exploits the knowledge of the digital halftoning scheme employed by the printer. Using the proposed methods, several hundred information bits can be embedded into images with perfect recovery against the print-scan operation. Moreover, the hidden images also survive several other attacks, such as Gaussian or median filtering, scaling or aspect ratio change, heavy JPEG compression, and rows and/or columns removal