This paper overviews one of the most important, interesting, and challenging problems in oncology, the problem of lung cancer diagnosis Developing an effective computer-aided diagnosis (CAD) system for lung cancer is of great clinical importance and can increase the patient's chance of survival For this reason, CAD systems for lung cancer have been investigated in a huge number of research studies A typical CAD system for lung cancer diagnosis is composed of four main processing steps: segmentation of the lung fields, detection of nodules inside the lung fields, segmentation of the detected nodules, and diagnosis of the nodules as benign or malignant This paper overviews the current state-of-the-art techniques that have been developed to implement each of these CAD processing steps For each technique, various aspects of technical issues, implemented methodologies, training and testing databases, and validation methods, as well as achieved performances, are described In addition, the paper addresses several challenges that researchers face in each implementation step and outlines the strengths and drawbacks of the existing approaches for lung cancer CAD systems

https://downloads.hindawi.com/journals/ijbi/2013/942353.pdf

Computer-Aided Diagnosis Systems for Lung Cancer: Challenges and Methodologies

Face images captured by surveillance cameras are often of low resolution (LR), which adversely affects the performance of their matching with high-resolution (HR) gallery images. Existing methods including super resolution, coupled mappings (CMs), multidimensional scaling, and convolutional neural network yield only modest performance. In this letter, we propose the deep coupled ResNet (DCR) model. It consists of one trunk network and two branch networks. The trunk network, trained by face images of three significantly different resolutions, is used to extract discriminative features robust to the resolution change. Two branch networks, trained by HR images and images of the targeted LR, work as resolution-specific CMs to transform HR and corresponding LR features to a space where their difference is minimized. Model parameters of branch networks are optimized using our proposed CM loss function, which considers not only the discriminability of HR and LR features, but also the similarity between them. In order to deal with various possible resolutions of probe images, we train multiple pairs of small branch networks while using the same trunk network. Thorough evaluation on LFW and SCface databases shows that the proposed DCR model achieves consistently and considerably better performance than the state of the arts.

Deep Coupled ResNet for Low-Resolution Face Recognition

Cross-modal retrieval has become a highlighted research topic, to provide flexible retrieval experience across multimedia data such as image, video, text and audio. The core of existing cross-modal retrieval approaches is to narrow down the gap between different modalities either by finding a maximally correlated embedding space. Recently, researchers leverage Deep Neural Network (DNN) to learn nonlinear transformations for each modality to obtain transformed features in a common subspace where cross-modal matching can be performed. However, the statistical characteristics of the original features for each modality are not explicitly preserved in the learned subspace. Inspired by recent advances in adversarial learning, we propose a novel Deep Adversarial Metric Learning approach, termed DAML for cross-modal retrieval. DAML nonlinearly maps labeled data pairs of different modalities into a shared latent feature subspace, under which the intra-class variation is minimized and the inter-class variation is maximized, and the difference of each data pair captured from two modalities of the same class is minimized, respectively. In addition to maximizing the correlations between modalities, we add an additional regularization by introducing adversarial learning. In particular, we introduce a modality classifier to predict the modality of a transformed feature, which ensures that the transformed features are also statistically indistinguishable. Experiments on three popular multimodal datasets show that DAML achieves superior performance compared to several state of the art cross-modal retrieval methods.

Deep adversarial metric learning for cross-modal retrieval

Faces convey a wealth of social signals, including race, expression, identity, age and gender, all of which have attracted increasing attention from multi-disciplinary research, such as psychology, neuroscience, computer science, to name a few. Gleaned from recent advances in computer vision, computer graphics, and machine learning, computational intelligence based racial face analysis has been particularly popular due to its significant potential and broader impacts in extensive real-world applications, such as security and defense, surveillance, human computer interface (HCI), biometric-based identification, among others. These studies raise an important question: How implicit, non-declarative racial category can be conceptually modeled and quantitatively inferred from the face? Nevertheless, race classification is challenging due to its ambiguity and complexity depending on context and criteria. To address this challenge, recently, significant efforts have been reported toward race detection and categorization in the community. This survey provides a comprehensive and critical review of the state-of-the-art advances in face-race perception, principles, algorithms, and applications. We first discuss race perception problem formulation and motivation, while highlighting the conceptual potentials of racial face processing. Next, taxonomy of feature representational models, algorithms, performance and racial databases are presented with systematic discussions within the unified learning scenario. Finally, in order to stimulate future research in this field, we also highlight the major opportunities and challenges, as well as potentially important cross-cutting themes and research directions for the issue of learning race from face.

/pdf/learning-race-from-face-a-survey-1x7a63ciop.pdf

Learning Race from Face: A Survey

A recent survey of iris biometric research from its inception through 2007, roughly 15 years of research, lists approximately 180 publications. This new survey is intended to update the previous one, and covers iris biometrics research over the period of roughly 2008–2010. Research in iris biometrics has expanded so much that, although covering only 3 years and intentionally being selective about coverage, this new survey lists a larger number of references than the inception-through-2007 survey.

https://www.springer.com/cda/content/document/cda_downloaddocument/9781447144014-c1.pdf?SGWID=0-0-45-1366206-p174543831

A Survey of Iris Biometrics Research: 2008–2010

Many scenarios require that face recognition be performed at conditions that are not optimal. Traditional face recognition algorithms are not best suited for matching images captured at a low-resolution to a set of high-resolution gallery images. To perform matching between images of different resolutions, this work proposes a method of learning two sets of projections, one for high-resolution images and one for low-resolution images, based on local relationships in the data. Subsequent matching is done in a common subspace. Experiments show that our algorithm yields higher recognition rates than other similar methods.

/pdf/coupled-marginal-fisher-analysis-for-low-resolution-face-1xmllppnu7.pdf

Coupled marginal fisher analysis for low-resolution face recognition

We report on an experiment in which observers were asked to browse a set of 100 iris images and group them into categories based on similarity of overall texture appearance. Results indicate that there is a natural categorization of iris images into a small number of high-level categories, and then also into subcategories. Also, the categorization reflects the Caucasian / Asian ethnicity of the person. This iris texture categorization has potential application in, for example, creating an indexing algorithm to speed search of an iris database and / or determining soft biometric traits of a person.

Human perceptual categorization of iris texture patterns

Biometrics systems typically work best in settings where probe samples are captured in the same manner as the training set. When biometrics are acquired under different conditions or with different sensors, naive approaches to recognition perform poorly. Coupled mappings have been introduced for performing face recognition across different resolutions, and learn a common subspace between different domains. In this paper, we introduce Maximum-Margin Coupled Mappings (MMCM), which aims to learn projections such that there is a margin of separation between pairs of cross-domain data from the same class and pairs of cross-domain data from different classes. While coupled mapping techniques have traditionally been used for matching face images at different resolutions, we demonstrate that MMCM is effective for cross-sensor biometric matching as well.

Maximum-Margin Coupled Mappings for cross-domain matching

Producing consistent segmentations of lung nodules in CT scans is a persistent problem of image processing algorithms. Many hard-segmentation approaches are proposed in the literature, but soft segmentation of lung nodules remains largely unexplored. In this paper, we propose a classification-based approach based on pixel-level texture features that produces soft (probabilistic) segmentations. We tested this classifier on the publicly available Lung Image Database Consortium (LIDC) dataset. We further refined the classification results with a post-processing algorithm based on the variability index. The algorithm performed well on nodules not adjacent to the chest wall, producing a soft overlap between radiologists' based segmentation and computer-based segmentation of 0.52. In the long term, these soft segmentations will be useful for representing the uncertainty in nodule boundaries that is manifest in radiological image segmentations.

/pdf/a-texture-based-probabilistic-approach-for-lung-nodule-4hre3vcfgn.pdf

A texture-based probabilistic approach for lung nodule segmentation

Visual tracking in unconstrained environments often involves following an object that exhibits a number of appearance changes from factors such as scale change, rotation, and illumination. Effective tracking requires adapting a tracker to the object's changing appearance over time. When a target becomes occluded by other objects in the scene, a naive tracker may end up learning the appearance of the occluding object. Our work introduces a method of detecting occlusion by considering the color profile of the target to prevent inappropriate tracker updates while the target is occluded. We show improved overlap and central location precision with three visual trackers when adding our hue-based occlusion detection to each tracking system.

Stephen Siena

Papers

Coupled marginal fisher analysis for low-resolution face recognition

Human perceptual categorization of iris texture patterns

Maximum-Margin Coupled Mappings for cross-domain matching

A texture-based probabilistic approach for lung nodule segmentation

Detecting occlusion from color information to improve visual tracking