Ralph Gross

Ralph Gross
Carnegie Mellon University | CMU · H. John Heinz III College

About

64
Publications
32,092
Reads
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14,601
Citations
Citations since 2017
0 Research Items
4827 Citations
20172018201920202021202220230200400600800
20172018201920202021202220230200400600800
20172018201920202021202220230200400600800
20172018201920202021202220230200400600800
Introduction
Skills and Expertise

Publications

Publications (64)
Article
Full-text available
We investigate the feasibility of combining publicly available Web 2.0 data with off-the-shelf face recognition software for the purpose of large-scale, automated individual re-identification. Two experiments illustrate the ability of identifying strangers online (on a dating site where individuals protect their identities by using pseudonyms) and...
Patent
Methods and systems for predicting statistically probable systematically assigned identifiers are disclosed, as are methods and systems for determining the likelihood that a systematically assigned identifier provided by a purported assignee of the identifier is legitimate. In one example, determining the likelihood of legitimacy includes determini...
Article
Full-text available
A close relationship exists between the advancement of face recognition algorithms and the availability of face databases varying factors that affect facial appearance in a controlled manner. The CMU PIE database has been very influential in advancing research in face recognition across pose and illumination. Despite its success the PIE database ha...
Article
Full-text available
Over the past decade, social network sites have experienced dramatic growth in popularity, reaching most demographics and providing new opportunities for interaction and socialization. Through this growth, users have been challenged to manage novel privacy concerns and balance nuanced trade-offs between disclosing and withholding personal informati...
Article
To be presented at BlackHat 2009. Introduction. In 1984, Perrow noted that critical failures are likely outcomes for complex systems whose parts interact in unpredictable ways (1). Increasingly complex information systems also can lead to unexpected failures: we show that interactions across data sources can be exploited to predict private SSNs fro...
Article
A close relationship exists between the advancement of face recognition algorithms and the availability of face databases varying factors that affect facial appearance in a controlled manner. The CMU PIE database has been very influential in advancing research in face recognition across pose and illumination. Despite its success the PIE database ha...
Article
Information about an individual's place and date of birth can be exploited to predict his or her Social Security number (SSN). Using only publicly available information, we observed a correlation between individuals' SSNs and their birth data and found that for younger cohorts the correlation allows statistical inference of private SSNs. The infere...
Chapter
Full-text available
With the emergence of new applications centered around the sharing of image data, questions concerning the protection of the privacy of people visible in the scene arise. In most of these applications, knowledge of the identity of people in the image is not required. This makes the case for image de-identification, the removal of identifying inform...
Conference Paper
With the emergence of new applications centered around the sharing of image data, questions concerning the protection of the privacy of people visible in the scene arise. Recently, formal methods for the de-identification of images have been proposed which would benefit from multi-factor coding to separate identity and non-identity related factors....
Article
With the emergence of new applications centered around the sharing of image data, questions concerning the protection of the privacy of people visible in the scene arise. This problem is particularly pressing for medical face database. While algorithms have been proposed for the de-identification of face images, they either lack a formal privacy pr...
Conference Paper
Full-text available
The increased demand for tighter border and building security has renewed public interest in biometric identification and verification systems. With fingerprint recognition being socially stigmatized, hand geometry-based recognizers have emerged as niche solutions. However, systems currently available in the marketplace require direct contact with...
Conference Paper
A wide range of technological advances have helped to make extensive image and video acquisition close to effortless. As a consequence many applications which capture image data of people for either immediate inspection or storage and subsequent sharing have become possible. Along with these improved recording capabilities, however, come concerns a...
Article
Full-text available
Information about person identity is multimodal. Yet, most person-recognition systems limit themselves to only a single modality, such as facial appearance. With a view to exploiting the complementary nature of different modes of information and increasing pattern recognition robustness to test signal degradation, we developed a multiple expert bio...
Conference Paper
Full-text available
The problem investigated in this paper is the quick identification of free-form 2D objects using a coefficient based indexing technique. We demonstrate that combining implicit polynomial shape descriptors with calibration techniques has the potential to quickly identify images of similar shapes. As a pilot experiment, our approach is evaluated agai...
Conference Paper
Full-text available
The ability to quickly compute hand geometry measurements from a freely posed hand offers advantages to biometric identification systems. While hand geometry systems are not new, typical measurements of lengths and widths of fingers and palms require rigid placement of the hand against pegs. Slight deviations in hand position, finger stretch or pre...
Conference Paper
Online social networks such as Friendster, MySpace, or the Facebook have experienced exponential growth in membership in recent years. These networks oer attractive means for inter- action and communication, but also raise privacy and security concerns. In this study we survey a representative sample of the members of the Facebook (a social network...
Article
Advances in camera and computing equipment hardware in recent years have made it increasingly simple to capture and store extensive amounts of video data. This, among other things, creates ample opportunities for the sharing of video sequences. In order to protect the privacy of subjects visible in the scene, automated methods to de-identify the im...
Article
Active Appearance Models (AAMs) are generative parametric models that have been successfully used in the past to model faces. Anecdotal evidence, however, suggests that the performance of an AAM built to model the variation in appearance of a single person across pose, illumination, and expression (a Person Specific AAM) is substantially better tha...
Conference Paper
Full-text available
Discriminatory information about person identity is multimodal. Yet, most person recognition systems are unimodal, e.g. the use of facial appearance. With a view to exploiting the complementary nature of different modes of information and increasing pattern recognition robustness to test signal degradation, we developed a multiple expert biometric...
Conference Paper
Full-text available
Subspace methods such as PCA, LDA, ICA have become a standard tool to perform visual learning and recognition. In this paper we propose representational oriented component analysis (ROCA), an extension of OCA, to perform face recognition when just one sample per training class is available. Several novelties are introduced in order to improve gener...
Chapter
Full-text available
The last decade has seen automatic face recognition evolve from small scale research systems to a wide range of commercial products. Driven by the FERET face database and evaluation protocol, the currently best commercial systems achieve verification accuracies comparable to those of fingerprint recognizers. In these experiments , only frontal face...
Conference Paper
Full-text available
With the proliferation of inexpensive video surveillance and face recognition technologies, it is increasingly possible to track and match people as they move through public spaces. To protect the privacy of subjects visible in video sequences, prior research suggests using ad hoc obfuscation methods, such as blurring or pixelation of the face. How...
Conference Paper
A dramatic increase or decrease in the number of people appearing at a location can be an indicator that something has happened that may be of interest to law-enforcement, public health, or security. This work demonstrates how low quality camera images can be used to automatically alert when an unusual number of people are absent or present at a lo...
Conference Paper
Participation in social networking sites has dramatically increased in recent years. Services such as Friendster, Tribe, or the Facebook allow millions of individuals to create online profiles and share personal information with vast networks of friends - and, often, unknown numbers of strangers. In this paper we study patterns of information revel...
Conference Paper
Active Appearance Models (AAMs) are generative parametric models that have been successfully used in the past to track faces in video. A variety of video applications are possible, including dynamic pose estimation for real-time user interfaces, lip-reading, and expression recognition. To construct an AAM, a number of training images of faces with...
Article
Full-text available
The non-rigid motion of a driver's head (i.e. the motion of their mouth, eye-brows, cheeks, etc) can tell us a lot about their mental state; e.g. whether they are drowsy, alert, aggressive, comfortable, tense, distracted, etc. In this paper, we describe our recent research on non- rigid face tracking. In particular, we present both 2D and 3D algori...
Article
Face recognition algorithms have to deal with significant amounts of illumination variations between gallery and probe images. State-of-the-art commercial face recognition algorithms still struggle with this problem. We propose a new image preprocessing algorithm that compensates for illumination variations in images. From a single brightness image...
Article
Active Appearance Models (AAMs) are generative parametric models that have been successfully used in the past to track faces in video. A variety of video applications are possible, including dynamic head pose and gaze estimation for real-time user interfaces, lip-reading, and expression recognition. To construct an AAM, a number of training images...
Article
Full-text available
Active Appearance Models (AAMs) are generative para- metric models that have been successfully used in the past to track faces in video. A variety of video applications are possible, including dynamic pose estimation for real- time user interfaces, lip-reading, and expression recogni- tion. To construct an AAM, a number of training images of faces...
Article
Full-text available
Arguably the most important decision to be made when developing an object recognition algorithm is selecting the scene measurements or features on which to base the algorithm. In appearance-based object recognition, the features are chosen to be the pixel intensity values in an image of the object. These pixel intensities correspond directly to the...
Article
Since the Lucas-Kanade algorithm was proposed in 1981 image alignment has become one of the most widely used techniques in computer vision. Applications range from optical flow, tracking, and layered motion, to mosaic construction, medical image registration, and face coding. Numerous algorithms have been proposed and a variety of extensions have b...
Article
Full-text available
The last decade has seen automatic face recognition evolve from small-scale research systems to a wide range of commercial products. Driven by the FERET face database and evaluation protocol, the currently best commercial systems achieve verification accuracies comparable to those of fingerprint recognizers. In these experiments, only frontal face...
Article
Full-text available
Since the Lucas-Kanade algorithm was proposed in 1981 image alignment has become one of the most widely used techniques in computer vision. Applications range from optical flow, tracking, and layered motion, to mosaic construction, medical image registration, and face coding. Numerous algorithms have been proposed and a variety of extensions have b...
Article
Arguably the most important decision to be made when developing an object recognition algorithm is selecting the scene measurements or features on which to base the algorithm. In appearance-based object recognition the features are chosen to be the pixel intensity values in an image of the object. These pixel intensities correspond directly to the...
Article
Segmentation and recognition have long been treated as two separate processes. We propose a mechanism based on spectral graph partitioning that readily combine the two processes into one. A part-based recognition system detects object patches, supplies their partial segmentations and knowledge about the spatial configurations of the object. The goa...
Article
Full-text available
Since the Lucas-Kanade algorithm was proposed in 1981, image alignment has become one of the most widely used techniques in computer vision. Applications range from optical flow, tracking and layered motion, to mosaic construction, medical image registration, and face coding. Numerous algorithms have been proposed and a wide variety of extensions h...
Article
Segmentation and recognition have long been treated as two separate processes.
Conference Paper
Full-text available
Face recognition algorithms have to deal with significant amounts of illumination variations between gallery and probe images. State-of-the-art commercial face recognition algorithms still struggle with this problem. We propose a new image preprocessing algorithm that compensates for illumination variations in images. From a single brightness image...
Article
Full-text available
This paper presents a multi-expert person identification system based on the integration of three separate systems employing audio features, static face images and lip motion features respectively. Audio person identification was carried out using a text dependent Hidden Markov Model methodology. Modeling of the lip motion was carried out using Gau...
Article
Our goal is to establish a simple baseline method for human identification based on body shape and gait. This baseline recognition method provides a lower bound against which to evaluate more complicated procedures. We present a viewpoint dependent technique based on template matching of body silhouettes. Cyclic gait analysis is performed to extrac...
Article
The face can communicate varied personal information including subjective emotion, communicative intent, and cognitive appraisal. Accurate interpretation by observer or computer interface depends on attention to dynamic properties of the expression, context, and knowledge of what is normative for a given individual. In two separate studies, we inve...
Article
Full-text available
The face can communicate varied personal information including subjective emotion, communicative intent, and cognitive appraisal. Accurate interpretation by observer or computer interface depends on attention to dynamic properties of the expression, context, and knowledge of what is normative for a given individual. In two separate studies, we inve...
Conference Paper
In this work we present an appearance-based 3-D Face Recognition approach that is able to recognize faces in video sequences, independent from face pose. For this we combine eigen light-fields with probabilistic propagation over time for evidence integration. Eigen light-fields allow us to build an appearance based 3-D model of an object; probabili...
Conference Paper
Full-text available
In many face recognition tasks the pose and illumination conditions of the probe and gallery images are different. In other cases multiple gallery or probe images may be available, each captured from a different pose and under a different illumination. We propose a face recognition algorithm which can use any number of gallery images per subject ca...
Article
Within the past decade, major advances have occurred in face recognition. Many systems have emerged that are capable of achieving recognition rates in excess of 90% accuracy under controlled conditions. In field settings, face images are subject to a wide range of variation that includes viewing, illumination, occlusion, facial expression, time del...
Conference Paper
Our goal is to establish a simple baseline method for human identification based on body shape and gait. This baseline recognition method provides a lower bound against which to evaluate more complicated procedures. We present a viewpoint-dependent technique based on template matching of body silhouettes. Cyclic gait analysis is performed to extrac...
Conference Paper
Full-text available
In many face recognition tasks, the pose of the probe and gallery images are different. In other cases, multiple gallery or probe images may be available, each captured from a different pose. We propose a face recognition algorithm which can use any number of gallery images per subject, captured at arbitrary poses, and any number of probe images, a...
Article
Full-text available
In many face recognition tasks the pose of the probe and gallery images are different. In other cases multiple gallery or probe images may be available, each captured from a different pose. We propose a face recognition algorithm which can use any number of gallery images per subject captured at arbitrary poses, and any number of probe images, agai...
Article
Full-text available
A meeting browser is a system that allows users to review a multimedia meeting record from a variety of indexing methods. Identification of meeting participants is essential for creating such a multimedia meeting record. Moreover, knowing who is speaking can enhance the performance of speech recognition and indexing meeting transcription. In this p...
Article
Full-text available
Within the past decade, major advances have occurred in face recognition. With few exceptions, however, most research has been limited to training and testing on frontal views. Little is known about the extent to which face pose, illumination, expression, occlusion, and individual differences, such as those associated with gender, influence recogni...
Article
In March 2001 we started to collect the CMU Motion of Body (MoBo) database. To date the database contains 25 individuals walking on a treadmill in the CMU 3D room. The subjects perform four different activities: slow walk, fast walk, incline walk and walking with a ball. All subjects are captured using six high resolution color cameras distributed...
Article
Full-text available
Face-to-face meetings usually encompass several modalities including speech, gesture, handwriting, and person identification. Recognition and integration of each of these modalities is important to create an accurate record of a meeting. However, each of these modalities presents recognition difficulties. Speech recognition must be speaker and doma...
Article
Full-text available
Face-to-face meetings usually encompass several modalities including speech, gesture, handwriting, and person identification. Recognition and integration of each of these modalities is important to create an accurate record of a meeting. However, each of these modalities presents recognition difficulties. Speech recognition must be speaker and doma...
Conference Paper
A major challenge for face recognition algorithms lies in the variance faces undergo while changing pose. This problem is typically addressed by building view dependent models based on face images taken from predefined head poses. However, it is impossible to determine all head poses beforehand in an unrestricted setting such as a meeting room, whe...
Conference Paper
We investigate the recognition of human faces in a meeting room. The major challenges of identifying human faces in this environment include low quality of input images, poor illumination, unrestricted head poses and continuously changing facial expressions and occlusion. In order to address these problems we propose a novel algorithm, dynamic spac...
Article
Online social networks such as Friendster, MySpace, or the Facebook have experienced exponential growth in membership in recent years. These networks oer attractive means for interaction and commu- nication, but also raise privacy and security concerns. In this study we survey a representative sample of the members of the Facebook (a social network...
Conference Paper
Full-text available
Designed as identifiers of accounts tracking US residents' earnings, Social Security numbers (SSNs) have become over time sensitive authenticators for private sector services. Since their abuse is a major vector of identity theft, numerous initiatives have attempted to reduce their public availability. However, recent research has shown that unavai...

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