Clustering is the unsupervised classification of patterns (observations, data items, or feature vectors) into groups (clusters). The clustering problem has been addressed in many contexts and by researchers in many disciplines; this reflects its broad appeal and usefulness as one of the steps in exploratory data analysis. However, clustering is a difficult problem combinatorially, and differences in assumptions and contexts in different communities has made the transfer of useful generic concepts and methodologies slow to occur. This paper presents an overview of pattern clustering methods from a statistical pattern recognition perspective, with a goal of providing useful advice and references to fundamental concepts accessible to the broad community of clustering practitioners. We present a taxonomy of clustering techniques, and identify cross-cutting themes and recent advances. We also describe some important applications of clustering algorithms such as image segmentation, object recognition, and information retrieval.

/pdf/data-clustering-a-review-4c452f5cab.pdf

Data clustering: a review

A major new professional reference work on fingerprint security systems and technology from leading international researchers in the field Handbook provides authoritative and comprehensive coverage of all major topics, concepts, and methods for fingerprint security systems This unique reference work is an absolutely essential resource for all biometric security professionals, researchers, and systems administrators

/pdf/handbook-of-fingerprint-recognition-16mh887j24.pdf

Handbook of Fingerprint Recognition

In order to ensure that the performance of an automatic fingerprint identification/verification system will be robust with respect to the quality of input fingerprint images, it is essential to incorporate a fingerprint enhancement algorithm in the minutiae extraction module. We present a fast fingerprint enhancement algorithm, which can adaptively improve the clarity of ridge and valley structures of input fingerprint images based on the estimated local ridge orientation and frequency. We have evaluated the performance of the image enhancement algorithm using the goodness index of the extracted minutiae and the accuracy of an online fingerprint verification system. Experimental results show that incorporating the enhancement algorithm improves both the goodness index and the verification accuracy.

/pdf/fingerprint-image-enhancement-algorithm-and-performance-405diava9j.pdf

Fingerprint image enhancement: algorithm and performance evaluation

The objective of this paper is to give a comprehensive introduction to applied cryptography with an engineer or computer scientist in mind. The emphasis is on the knowledge needed to create practical systems which supports integrity, confidentiality, or authenticity. Topics covered includes an introduction to the concepts in cryptography, attacks against cryptographic systems, key use and handling, random bit generation, encryption modes, and message authentication codes. Recommendations on algorithms and further reading is given in the end of the paper. This paper should make the reader able to build, understand and evaluate system descriptions and designs based on the cryptographic components described in the paper.

[서평]「Applied Cryptography」

IEEE Transactions on Pattern Analysis and Machine Intelligence

Technical solutions are described for training an object-recognition neural network that identifies an object in a computer-readable image. An example method includes assigning a first neural network for determining a visual alignment model of the images for determining a normalized alignment of the object. The method further includes assigning a second neural network for determining a visual representation model of the images for recognizing the object. The method further includes determining the visual alignment model by training the first neural network and determining the visual representation model by training the second neural network independent of the first. The method further includes determining a combined object recognition model by training a combination of the first neural network and the second neural network. The method further includes recognizing the object in the image based on the combined object recognition model by passing the image through each of the neural networks.

Visual object recognition

Cognitive data augmentation for adversarial defense via pixel masking

Techniques for generating a distorted template for a given facial image are provided. First, at least one facial feature point from a given facial image is selected. The selected facial feature has location information associated therewith. A representation of a region proximate to the selected facial feature point is then generated. Next, the location information associated with the selected facial feature point and/or the representation of the region proximate to the selected facial feature point are distorted. A distorted template is then formed, wherein the distorted template comprises the distorted location information associated with the selected facial feature point and/or the distorted representation of the region proximate to the selected facial feature point.

Methods and apparatus for generation of cancelable face template

Deep learning solutions are vulnerable to adversarial perturbations and can lead a "frog" image to be misclassified as a "deer" or random pattern into "guitar". Adversarial attack generation algorithms generally utilize the knowledge of database and CNN model to craft the noise. In this research, we present a novel scheme termed as Camera Inspired Perturbations to generate adversarial noise. The proposed approach relies on the noise embedded in the image due to environmental factors or camera noise incorporated. We extract these noise patterns using image filtering algorithms and incorporate them into images to generate adversarial images. Unlike most of the existing algorithms that require learning of noise, the proposed adversarial noise can be applied in real-time. It is model-agnostic and can be utilized to fool multiple deep learning classifiers on various databases. The effectiveness of the proposed approach is evaluated on five different databases with five different convolutional neural networks such as ResNet-50, VGG-16, and VGG-Face. The proposed attack reduces the classification accuracy of every network, for instance, the performance of VGG-16 on the Tiny ImageNet database is reduced by more than 33%. The robustness of the proposed adversarial noise is also evaluated against different adversarial defense algorithms.

/pdf/noise-is-inside-me-generating-adversarial-perturbations-with-1bc54yh2q9.pdf

Noise is Inside Me! Generating Adversarial Perturbations with Noise Derived from Natural Filters

Performance of a biometric system is characterized by its speed, accuracy, and cost This paper presents fundamentals of 1 : 1 biometric match engine accuracy performance metrics and its evaluation Here, we explain the basic terminology, performance metrics and related system issues We also discuss practical methods used for evaluating 1 : 1 biometric match engine accuracy performance and provide a summary of the state-of-art of biometric identifier accuracies.

Nalini K. Ratha

Papers

Visual object recognition

Cognitive data augmentation for adversarial defense via pixel masking

Methods and apparatus for generation of cancelable face template

Noise is Inside Me! Generating Adversarial Perturbations with Noise Derived from Natural Filters

Performance evaluation in 1: 1 biometric engines