Novel techniques are necessary in order to improve the current state-of-the-art for Aided Target Recognition (AiTR) especially for persistent intelligence, surveillance, and reconnaissance (ISR). A fundamental assumption that current AiTR systems make is that operating conditions remain semi-consistent between the training samples and the testing samples. Today’s electro-optical AiTR systems are still not robust to common occurrences such as changes in lighting conditions. In this work, we explore the effect of systemic variation in lighting conditions on vehicle recognition performance. In addition, we explore the use of low-dimensional nonlinear representations of high-dimensional data derived from electro-optical synthetic vehicle images using Manifold Learning - specifically Diffusion Maps on recognition. Diffusion maps have been shown to be a valuable tool for extraction of the inherent underlying structure in high-dimensional data.
Gender classification is a critical component of a robust image security system. Many techniques exist to perform gender classification using facial features. In contrast, this paper explores gender classification using body features extracted from clothed subjects. Several of the most effective types of features for gender classification identified in literature were implemented and applied to the newly developed Seasonal Weather And Gender (SWAG) dataset. SWAG contains video clips of approximately 2000 samples of human subjects captured over a period of several months. The subjects are wearing casual business attire and outer garments appropriate for the specific weather conditions observed in the Midwest. The results from a series of experiments are presented that compare the classification accuracy of systems that incorporate various types and combinations of features applied to multiple looks at subjects at different image resolutions to determine a baseline performance for gender classification.
This paper provides an overview of deep learning and introduces the several subfields of deep learning including a specific tutorial of convolutional neural networks. Traditional methods for learning image features are compared to deep learning techniques. In addition, we present our preliminary classification results, our basic implementation of a convolutional restricted Boltzmann machine on the Mixed National Institute of Standards and Technology database (MNIST), and we explain how to use deep learning networks to assist in our development of a robust gender classification system.
This paper describes the process used to collect the Seasonal Weather And Gender (SWAG) dataset; an electro-optical
dataset of human subjects that can be used to develop advanced gender classification algorithms. Several novel features
characterize this ongoing effort (1) the human subjects self-label their gender by performing a specific action during the
data collection and (2) the data collection will span months and even years resulting in a dataset containing realistic
levels and types of clothing corresponding to the various seasons and weather conditions. It is envisioned that this type
of data will support the development and evaluation of more robust gender classification systems that are capable of
accurate gender recognition under extended operating conditions.
In this paper we extend a previous exploration of histogram features extracted from 3D point cloud images of human
subjects for gender discrimination. Feature extraction used a collection of concentric cylinders to define volumes for
counting 3D points. The histogram features are characterized by a rotational axis and a selected set of volumes derived
from the concentric cylinders. The point cloud images are drawn from the CAESAR anthropometric database provided
by the Air Force Research Laboratory (AFRL) Human Effectiveness Directorate and SAE International. This database
contains approximately 4400 high resolution LIDAR whole body scans of carefully posed human subjects. Success from
our previous investigation was based on extracting features from full body coverage which required integration of
multiple camera images. With the full body coverage, the central vertical body axis and orientation are readily
obtainable; however, this is not the case with a one camera view providing less than one half body coverage. Assuming
that the subjects are upright, we need to determine or estimate the position of the vertical axis and the orientation of the
body about this axis relative to the camera. In past experiments the vertical axis was located through the center of mass
of torso points projected on the ground plane and the body orientation derived using principle component analysis.
In a natural extension of our previous work to partial body views, the absence of rotational invariance about the
cylindrical axis greatly increases the difficulty for gender classification. Even the problem of estimating the axis is no
longer simple. We describe some simple feasibility experiments that use partial image histograms. Here, the cylindrical
axis is assumed to be known. We also discuss experiments with full body images that explore the sensitivity of
classification accuracy relative to displacements of the cylindrical axis. Our initial results provide the basis for further
investigation of more complex partial body viewing problems and new methods for estimating the two position coordinates for the axis location and the unknown body orientation angle.
A growing body of discoveries in molecular signatures has revealed that volatile organic compounds (VOCs), the small
molecules associated with an individual's odor and breath, can be monitored to reveal the identity and presence of a
unique individual, as well their overall physiological status. Given the analysis requirements for differential VOC
profiling via gas chromatography/mass spectrometry, our group has developed a novel informatics platform, Metabolite
Differentiation and Discovery Lab (MeDDL). In its current version, MeDDL is a comprehensive tool for time-series
spectral registration and alignment, visualization, comparative analysis, and machine learning to facilitate the efficient
analysis of multiple, large-scale biomarker discovery studies. The MeDDL toolset can therefore identify a large
differential subset of registered peaks, where their corresponding intensities can be used as features for classification.
This initial screening of peaks yields results sets that are typically too large for incorporation into a portable, electronic
nose based system in addition to including VOCs that are not amenable to classification; consequently, it is also
important to identify an optimal subset of these peaks to increase classification accuracy and to decrease the cost of the
final system. MeDDL's learning tools include a classifier similar to a K-nearest neighbor classifier used in conjunction
with a genetic algorithm (GA) that simultaneously optimizes the classifier and subset of features. The GA uses ROC
curves to produce classifiers having maximal area under their ROC curve. Experimental results on over a dozen
recognition problems show many examples of classifiers and feature sets that produce perfect ROC curves.
In this paper we explore the use of histogram features extracted from 3D point clouds of human subjects for gender
classification. Experiments are conducted using point clouds drawn from the CAESAR anthropometric database
provided by the Air Force Research Laboratory (AFRL) Human Effectiveness Directorate and SAE International. This
database contains approximately 4400 high resolution LIDAR whole body scans of carefully posed human subjects.
Features are extracted from each point cloud by embedding the cloud in series of cylindrical shapes and computing a
point count for each cylinder that characterizes a region of the subject. These measurements define rotationally invariant
histogram features that are processed by a classifier to label the gender of each subject. Preliminary results using
cylinder sizes defined by human experts demonstrate that gender can be predicted with 98% accuracy for the type of
high density point cloud found in the CAESAR database. When point cloud densities are reduced to levels that might be
obtained using stand-off sensors; gender classification accuracy degrades. We introduce an evolutionary algorithm to
optimize the number and size of the cylinders used to define histogram features. The objective of this optimization
process is to identify a set of cylindrical features that reduces the error rate when predicting gender from low density
point clouds. A wrapper approach is used to interleave feature selection with classifier evaluation to train the
evolutionary algorithm. Results of classification accuracy achieved using the evolved features are compared to the
baseline feature set defined by human experts.
Color is an important feature for object recognition in security and military applications. Unfortunately, color is sensitive to the environmental operating conditions so its use for automatic target recognition is often limited. Recently a number of research efforts have focused on techniques for developing algorithms to improve color constancy across images. Many of these approaches attempt to improve the color constancy of a particular type of surface area such as skin. In contrast, we present an approach that attempts to address color constancy of many surfaces across a wide range of external environmental conditions in the absence of direct knowledge of illumination. Our approach builds on existing techniques by using evolutionary learning to synthesize features that characterize the illuminations that influence perception of color. Once the illumination of each image in a collection is estimated, it can be used to map the colors in an image to the illumination conditions in any other image. This would allows us to take an image from that collection, transform its colors to reference colors that can then be combined with other types of features (e.g. geometrical, statistical, and textural) to cerate automatic target recognition systems that are relatively insensitive to their operating conditions. To demonstrate our technique, we process images of a parking area under a wide variety of seasonal weather conditions collected across large timescales of hours, days, and months.
Classification of 3D objects is becoming an increasingly important research area due to cheap and innovative sensor technology. Shadows, noise, viewing direction, and distance from the sensor all directly affect the quality and amount of surface information provided by the sensor. The recognition approach described in this paper converts surface information, a set of (x,y,z) points, into a discrete 3D binary image. This conversion step processes the surface points using a fuzzy technique to mitigate the effects of noise and minor distortions. These images are then processed by sequences of one or two randomly selected morphological operators. Each of the sequences' output is then fed into a simple transducer to obtain a set of scalar feature values. The feature values are classified using a K nearest neighbor (KNN) classifier that is trained using a sparse number of training samples. Experiments were conducted using the Air Force Research Laboratory's E3D data and experimental protocol. Experimental results for the tank classification problem using 10 tanks and 26 confusers are presented. The results show the combination of morphological processing and KNN classifier produced consistently good performance under variations in noise, viewing angle, or distance.
In this paper, we discuss an initial effort to generate pattern recognizers using a multi- resolution Gabor stack of filtered images and a simple evolutionary search algorithm. The generated feature detectors are sets of pixel detectors that measure intensities and pass these values as feature vectors to neural net classifiers. We demonstrate the use of random search to solve a discrimination problem in which tank images are separated from other military vehicle images. The techniques and results used in this paper for discrimination of grey-scale images are reminiscent of similar approaches used to generate pattern recognizers for binary images. A sparse sampling of the Gabor image stack, using only 35 pixel detectors, produces feature vectors which are readily separated by linear perceptrons.
An important research objective is to develop systems which automatically generate target recognition programs. This paper presents evidence that such general goals are not feasible. Specifically, the problem of automatically synthesizing target recognition programs is shown to be NP-Complete. The intractability of this problem motivates a problem specification which is tolerant of errors. Although easier, this too is shown to be NP-Complete. These results indicate that automatic target recognition has computational limitations which are inherent in the problem specification, and not necessarily a lack of clever system designs.
KEYWORDS: Silicon, Image processing, Detection and tracking algorithms, Information operations, Feature extraction, Chemical elements, Composites, Evolutionary algorithms, Aluminum, Binary data
Morphological sequences (algorithms or programs) are generated using an evolutionary approach. A population of morphological sequences is manipulated and expanded in discrete steps. At each time-step two tasks are initiated--program discovery and program construction. The discovery phase searches for short morphological sequences which extract novel features. Program composition utilizes these sequences, which are partial solutions, to form increasingly effective sequences. The composition phase selects pairs of sequences and combines them into extended sequences which capture spatial relationships. The enhanced population serves as the basis for another phase of discovery and composition. Several demonstrations illustrate the system's ability to synthesize and integrate feature extraction routines.
The basis of a system for processing binary images with the operations of mathematical morphology is described. This system exploits the properties of mathematical morphology to minimize computing time and storage requirements. Images are stored in data structures which are memory-efficient and allow several images to be processed simultaneously. Techniques are also presented for efficiently storing globally sized structuring elements. These ternary images are stored in data structures which utilize an adaptive window to provide storage for a 2M X 2N specification space in an optimal M X N data structure. This representation provides efficient storage, retrieval, and comparison of generalized structuring elements.
A closed-loop hybrid learning system that facilitates the automatic design of a multi-class pattern recognition system is described. The design process has three phases: feature detector generation feature set selection and classification. In the first phase a large population of feature detectors based on morphological erosion and hit-or-miss operators is generated randomly. From this population an optimized subset of features is selected using a novel application of genetic algorithms. The selected features are then used to initialize a generalized Hamming neural network that performs image classification. This network provides the means for self-organizing the set of training patterns into additional subclasses this in turn dynamically alters the number of detectors and the size of the neural network. The design process uses system errors to gradually refine the set of feature vectors used in the classification subsystem. We describe an experiment in which the hybrid learning paradigm successfully generates a machine that distinguishes ten classes of handprinted numerical characters.
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