Machine Learning is the study of methods for programming computers to learn. Computers are applied to a wide range of tasks, and for most of these it is relatively easy for programmers to design and implement the necessary software. However, there are many tasks for which this is difficult or impossible. These can be divided into four general categories. First, there are problems for which there exist no human experts. For example, in modern automated manufacturing facilities, there is a need to predict machine failures before they occur by analyzing sensor readings. Because the machines are new, there are no human experts who can be interviewed by a programmer to provide the knowledge necessary to build a computer system. A machine learning system can study recorded data and subsequent machine failures and learn prediction rules. Second, there are problems where human experts exist, but where they are unable to explain their expertise. This is the case in many perceptual tasks, such as speech recognition, hand-writing recognition, and natural language understanding. Virtually all humans exhibit expert-level abilities on these tasks, but none of them can describe the detailed steps that they follow as they perform them. Fortunately, humans can provide machines with examples of the inputs and correct outputs for these tasks, so machine learning algorithms can learn to map the inputs to the outputs. Third, there are problems where phenomena are changing rapidly. In finance, for example, people would like to predict the future behavior of the stock market, of consumer purchases, or of exchange rates. These behaviors change frequently, so that even if a programmer could construct a good predictive computer program, it would need to be rewritten frequently. A learning program can relieve the programmer of this burden by constantly modifying and tuning a set of learned prediction rules. Fourth, there are applications that need to be customized for each computer user separately. Consider, for example, a program to filter unwanted electronic mail messages. Different users will need different filters. It is unreasonable to expect each user to program his or her own rules, and it is infeasible to provide every user with a software engineer to keep the rules up-to-date. A machine learning system can learn which mail messages the user rejects and maintain the filtering rules automatically. Machine learning addresses many of the same research questions as the fields of statistics, data mining, and psychology, but with differences of emphasis. Statistics focuses on understanding the phenomena that have generated the data, often with the goal of testing different hypotheses about those phenomena. Data mining seeks to find patterns in the data that are understandable by people. Psychological studies of human learning aspire to understand the mechanisms underlying the various learning behaviors exhibited by people (concept learning, skill acquisition, strategy change, etc.).

Machine learning

Today, the most accurate steganalysis methods for digital media are built as supervised classifiers on feature vectors extracted from the media. The tool of choice for the machine learning seems to be the support vector machine (SVM). In this paper, we propose an alternative and well-known machine learning tool-ensemble classifiers implemented as random forests-and argue that they are ideally suited for steganalysis. Ensemble classifiers scale much more favorably w.r.t. the number of training examples and the feature dimensionality with performance comparable to the much more complex SVMs. The significantly lower training complexity opens up the possibility for the steganalyst to work with rich (high-dimensional) cover models and train on larger training sets-two key elements that appear necessary to reliably detect modern steganographic algorithms. Ensemble classification is portrayed here as a powerful developer tool that allows fast construction of steganography detectors with markedly improved detection accuracy across a wide range of embedding methods. The power of the proposed framework is demonstrated on three steganographic methods that hide messages in JPEG images.

/pdf/ensemble-classifiers-for-steganalysis-of-digital-media-14urqbpk2p.pdf

Ensemble Classifiers for Steganalysis of Digital Media

Face detection has been one of the most studied topics in the computer vision literature. In this technical report, we survey the recent advances in face detection for the past decade. The seminal Viola-Jones face detector is first reviewed. We then survey the various techniques according to how they extract features and what learning algorithms are adopted. It is our hope that by reviewing the many existing algorithms, we will see even better algorithms developed to solve this fundamental computer vision problem. 1

https://www.microsoft.com/en-us/research/wp-content/uploads/2016/02/facedetsurvey.pdf

A Survey of Recent Advances in Face Detection

Audio- and video-based biometric person authentication

https://ibug.doc.ic.ac.uk/media/uploads/documents/face_detection_survey.pdf

A survey on face detection in the wild

Face detection with boosted Gaussian features

Information theoretic combination of pattern classifiers

In this paper we present a computer based approach to analysis of social interaction experiments for the diagnosis of autism spectrum disorders in young children of 6-18 months of age We apply face detection on videos from a head-mounted wireless camera to measure the time a child spends looking at people In-Plane rotation invariant Face Detection is used to detect faces from the diverse directions of the children’s head Skin color detection is used to render the system more robust to cluttered environments and to the poor quality of the video recording

/pdf/analysis-of-head-mounted-wireless-camera-videos-for-early-3t0zk2fcfs.pdf

Analysis of Head Mounted Wireless Camera Videos for Early Diagnosis of Autism

Combining several classifiers has proved to be an efficient machine learning technique. We propose a new measure of the goodness of an ensemble of classifiers in an information theoretic framework. It measures a trade-off between diversty and individual classifier accuracy. This technique can be directly used for the selection of an ensemble in a pool of classifiers. We also propose a variant of AdaBoost for directly training the classifiers by taking into account this new information theoretic measure.

Information theoretic combination of classifiers with application to AdaBoost

In this paper, a fast and an effective multi-view face tracking algorithm with head pose estimation is introduced. For modeling the face pose we employ a tree of boosted classifiers built using either Haar-like filters or Gauss filters. A first classifier extracts faces of any pose from the background. Then more specific classifiers discriminate between different poses. The tree of classifiers is trained by hierarchically sub-sampling the pose space. Finally, Condensation algorithm is used for tracking the faces. Experiments show large improvements in terms of detection rate and processing speed compared to state-of-the-art algorithms.

/pdf/fast-multi-view-face-tracking-with-pose-estimation-3rakcpy8xd.pdf

Julien Meynet

Papers

Face detection with boosted Gaussian features

Information theoretic combination of pattern classifiers

Analysis of Head Mounted Wireless Camera Videos for Early Diagnosis of Autism

Information theoretic combination of classifiers with application to AdaBoost

Fast multi-view face tracking with pose estimation