Real-time tracking of multiple objects with locally adaptive correlation filters

A tracking algorithm using locally adaptive correlation filtering is proposed. The algorithm is designed to track multiple objects withinvariancetopose,occlusion,clutter,andilluminationvariations. Thealgorithmemploysapredictionschemeandcomposite correlationfilters. Thefiltersaresynthesizedwiththehelpofaniterativealgorithm,whichoptimizesdiscriminationcapabilityfor each target. The filters are adapted online to targets changes using information of current and past scene frames. Results obtained with the proposed algorithm using real-life scenes, are presented and compared with those obtained with state-of-the-art tracking methods in terms of detection efficiency, tracking accuracy, and speed of processing.This work was supported by the Russian Science Foundation, grant no. 15-19-10010

Robust estimation of similarity transformation for visual object tracking

National Research Foundation (NRF) Singapore under its AI Singapore Programm

Fluoresoivien partikkeleiden havaitseminen kolibakteereissa

Escherichia coli are one of the most commonly used bacteria to study important biolog-ical processes such as transcription and translation. This is due to its simple structure and gene expression system, as well as the easiness to maintain live cultures in a laboratory environment. Due to recent developments in fluorescence microscopy and fluorescence labeling, it is now possible to study such biological processes in live cells at single cell and single molecule level. When analyzing such biological processes, the detection of fluorescent objects and subcellular particles is usually one of the first tasks providing important information for subsequent data analysis. Although many algorithms have been proposed for the task, it still remains a challenge due to the limitations of image acquisition when imaging live cells. For example, the intensity of the illumination light and the exposure time is usually minimized to prevent damage to the cells, resulting in images with low signal-to-noise ratio. Due to this and the large amount of data typically used for these studies, automated, high quality parti-cle detection algorithms are needed. In this thesis, we present a novel method for detecting fluorescently labeled subcellular particles in Escherichia coli. The proposed method is tested in both synthetic and em-pirical images and is compared to previous, commonly used methods using standard performance evaluation metrics. The results indicate that the proposed algorithm has a good performance with all image types tested and that it outperforms the previous methods. It is also able to achieve good results with other types of cells than E. coli. Moreover, it allows a robust detection of particles from low signal-to-noise ratio images with good accuracy, thus providing accurate and unbiased results for subsequent analy-sis

Target tracking with composite linear filters on noisy scenes

A tracking system using a bank of adaptive linear filters is proposed. Tracking is carried out by means of multiple target detections. The linear filters are designed from multiple views of a target using synthetic discriminant functions. For each view an optimum filter is derived from noisy reference image and disjoint background model. An iterative algorithm is used to improve the performance of the synthesized filters. The number of filters in the bank can be controlled to guarantee a prescribed tracking accuracy. Computer simulation results show that the proposed algorithm is able to precisely track a target.This work was supported the Russian Science Foundation grant №15-19-10010

Long Range Automated Persistent Surveillance

This dissertation addresses long range automated persistent surveillance with focus on three topics: sensor planning, size preserving tracking, and high magnification imaging. field of view should be reserved so that camera handoff can be executed successfully before the object of interest becomes unidentifiable or untraceable. We design a sensor planning algorithm that not only maximizes coverage but also ensures uniform and sufficient overlapped camera’s field of view for an optimal handoff success rate. This algorithm works for environments with multiple dynamic targets using different types of cameras. Significantly improved handoff success rates are illustrated via experiments using floor plans of various scales. Size preserving tracking automatically adjusts the camera’s zoom for a consistent view of the object of interest. Target scale estimation is carried out based on the paraperspective projection model which compensates for the center offset and considers system latency and tracking errors. A computationally efficient foreground segmentation strategy, 3D affine shapes, is proposed. The 3D affine shapes feature direct and real-time implementation and improved flexibility in accommodating the target’s 3D motion, including off-plane rotations. The effectiveness of the scale estimation and foreground segmentation algorithms is validated via both offline and real-time tracking of pedestrians at various resolution levels. Face image quality assessment and enhancement compensate for the performance degradations in face recognition rates caused by high system magnifications and long observation distances. A class of adaptive sharpness measures is proposed to evaluate and predict this degradation. A wavelet based enhancement algorithm with automated frame selection is developed and proves efficient by a considerably elevated face recognition rate for severely blurred long range face images

Multiple layer image analysis for video microscopy

Motion analysis is a fundamental problem that serves as the basis for many other image analysis tasks, such as structure estimation and object segmentation. Many motion analysis techniques assume that objects are opaque and non-reflective, asserting that a single pixel is an observation of a single scene object. This assumption breaks down when observing semitransparent objects--a single pixel is an observation of the object and whatever lies behind it. This dissertation is concerned with methods for analyzing multiple layer motion in microscopy, a domain where most objects are semitransparent. I present a novel approach to estimating the transmission of light through stationary, semitransparent objects by estimating the gradient of the constant transmission observed over all frames in a video. This enables removing the non-moving elements from the video, providing an enhanced view of the moving elements. I present a novel structured illumination technique that introduces a semitransparent pattern layer to microscopy, enabling microscope stage tracking even in the presence of stationary, sparse, or moving specimens. Magnitude comparisons at the frequencies present in the pattern layer provide estimates of pattern orientation and focal depth. Two pattern tracking techniques are examined, one based on phase correlation at pattern frequencies, and one based on spatial correlation using a model of pattern layer appearance based on microscopy image formation. Finally, I present a method for designing optimal structured illumination patterns tuned for constraints imposed by specific microscopy experiments. This approach is based on analysis of the microscope's optical transfer function at different focal depths

LANDSAT-D investigations in snow hydrology

Work undertaken during the contract and its results are described. Many of the results from this investigation are available in journal or conference proceedings literature - published, accepted for publication, or submitted for publication. For these the reference and the abstract are given. Those results that have not yet been submitted separately for publication are described in detail. Accomplishments during the contract period are summarized as follows: (1) analysis of the snow reflectance characteristics of the LANDSAT Thematic Mapper, including spectral suitability, dynamic range, and spectral resolution; (2) development of a variety of atmospheric models for use with LANDSAT Thematic Mapper data. These include a simple but fast two-stream approximation for inhomogeneous atmospheres over irregular surfaces, and a doubling model for calculation of the angular distribution of spectral radiance at any level in an plane-parallel atmosphere; (3) incorporation of digital elevation data into the atmospheric models and into the analysis of the satellite data; and (4) textural analysis of the spatial distribution of snow cover

Megapixel camera arrays enable high-resolution animal tracking in multiwell plates

Tracking small laboratory animals such as flies, fish, and worms is used for phenotyping in neuroscience, genetics, disease modelling, and drug discovery. An imaging system with sufficient throughput and spatiotemporal resolution would be capable of imaging a large number of animals, estimating their pose, and quantifying detailed behavioural differences at a scale where hundreds of treatments could be tested simultaneously. Here we report an array of six 12-megapixel cameras that record all the wells of a 96-well plate with sufficient resolution to estimate the pose of C. elegans worms and to extract high-dimensional phenotypic fingerprints. We use the system to study behavioural variability across wild isolates, the sensitisation of worms to repeated blue light stimulation, the phenotypes of worm disease models, and worms’ behavioural responses to drug treatment. Because the system is compatible with standard multiwell plates, it makes computational ethological approaches accessible in existing high-throughput pipelines