@inproceedings{jacob_snyder_2015, title={Learning rule for associative memory in recurrent neural networks}, DOI={10.1109/ijcnn.2015.7280532}, abstractNote={We present a new learning rule for intralayer connections in neural networks. The rule is based on Hebbian learning principles and is derived from information theoretic considerations. A simple network trained using the rule is shown to have associative memory like properties. The network acts by building connections between correlated data points, under constraints.}, booktitle={2015 international joint conference on neural networks (ijcnn)}, author={Jacob, T. and Snyder, W.}, year={2015} }
 @inproceedings{riggan_snyder_wang_feng_2014, title={A human factors study of graphical passwords using biometrics}, volume={8753}, booktitle={Pattern recognition, gcpr 2014}, author={Riggan, B. S. and Snyder, W. E. and Wang, X. G. and Feng, J.}, year={2014}, pages={464–475} }
 @inproceedings{huang_snyder_2013, title={Panorama creation using a team of robots}, DOI={10.1109/worv.2013.6521922}, abstractNote={A system is presented which allows a single human to teleoperate a team of camera-equipped robots. This paper emphasizes the image processing required to take a number of views and construct a single panorama which provides a sense of a 3-D environment to the operator who finds it easy to comprehend the environment and to control the team using something as simple as a joystick. Since the cameras have diverse poses, their output images must be distorted to provide smooth alignment. This is accomplished by correspondence finding, triangular tessellation and warping of a portion of each view. The panorama which gives a 180° field-of-view is projected onto a semi-circular array of monitors to provide the operator with a sensation of both forward and peripheral views.}, booktitle={2013 IEEE Workshop on Robot Vision (WORV)}, author={Huang, Y. Q. and Snyder, W.}, year={2013}, pages={108–113} }
 @article{heinrich_snyder_frahm_2011, title={Maximum likelihood autocalibration}, volume={29}, ISSN={["1872-8138"]}, DOI={10.1016/j.imavis.2011.07.003}, abstractNote={This paper addresses the problem of autocalibration, which is a critical step in existing uncalibrated structure from motion algorithms that utilize an initialization to avoid the local minima in metric bundle adjustment. Currently, all known direct (not non-linear) solutions to the uncalibrated structure from motion problem solve for a projective reconstruction that is related to metric by some unknown homography, and hence a necessary step in obtaining a metric reconstruction is the subsequent estimation of the rectifying homography, known as autocalibration. Although autocalibration is a well-studied problem, previous approaches have relied upon heuristic objective functions, and have a reputation for instability. We propose a maximum likelihood objective and show that it can be implemented robustly and efficiently and often provides substantially greater accuracy, especially when there are fewer views or greater noise.}, number={10}, journal={IMAGE AND VISION COMPUTING}, author={Heinrich, Stuart B. and Snyder, Wesley E. and Frahm, Jan-Michael}, year={2011}, month={Sep}, pages={653–665} }
 @article{gupta_snyder_pitts_2010, title={Concurrent visual multiple lane detection for autonomous vehicles}, ISSN={["2577-087X"]}, DOI={10.1109/robot.2010.5509389}, abstractNote={This paper proposes a monocular vision solution to simultaneous detection of multiple lanes in navigable regions / urban roads using accumulator voting. Unlike other approaches in literature, this paper first examines the extent of lane parameters required for continuous control of any vehicle manually or autonomously. The accumulator-based algorithm is designed using this fundamental control knowledge to vote for the required lane parameters (position of lanes and steering angle required) in the image plane. The novel accumulator voting scheme is called “Parametric Transform for Multi-lane Detection.” This paper not only adapts predictive control in the image plane, but also detects multiple lanes in the scene concurrently in the form of multiple peaks in the accumulator. This method is robust to shadows and invariant to color, texture, and width of the road. Finally, the method is designed for dashed/continuous lines.}, journal={2010 IEEE INTERNATIONAL CONFERENCE ON ROBOTICS AND AUTOMATION (ICRA)}, author={Gupta, Rachana Ashok and Snyder, Wesley and Pitts, W. Shepherd}, year={2010}, pages={2416–2422} }
 @article{krish_heinrich_snyder_cakir_khorram_2010, title={Global registration of overlapping images using accumulative image features}, volume={31}, ISSN={0167-8655}, url={http://dx.doi.org/10.1016/j.patrec.2009.09.016}, DOI={10.1016/j.patrec.2009.09.016}, abstractNote={This paper introduces a new feature-based image registration technique which registers images by finding rotation- and scale-invariant features and matching them using a novel feature matching algorithm based on an evidence accumulation process reminiscent of the generalized Hough transform. Once feature correspondence has been established, the transformation parameters are then estimated using non-linear least squares (NLLS) and the standard RANSAC (random sample consensus) algorithm. The technique is evaluated under similarity transforms – translation, rotation and scale (zoom) and also under illumination changes.}, number={2}, journal={Pattern Recognition Letters}, publisher={Elsevier BV}, author={Krish, Karthik and Heinrich, Stuart and Snyder, Wesley E. and Cakir, Halil and Khorram, Siamak}, year={2010}, month={Jan}, pages={112–118} }
 @article{miao_qi_ramanath_snyder_2006, title={Binary tree-based generic demosaicking algorithm for multispectral filter arrays}, volume={15}, ISSN={["1941-0042"]}, DOI={10.1109/TIP.2006.877476}, abstractNote={In this paper, we extend the idea of using mosaicked color filter array (CFA) in color imaging, which has been widely adopted in the digital color camera industry, to the use of multispectral filter array (MSFA) in multispectral imaging. The filter array technique can help reduce the cost, achieve exact registration, and improve the robustness of the imaging system. However, the extension from CFA to MSFA is not straightforward. First, most CFAs only deal with a few bands (3 or 4) within the narrow visual spectral region, while the design of MSFA needs to handle the arrangement of multiple bands (more than 3) across a much wider spectral range. Second, most existing CFA demosaicking algorithms assume the fixed Bayer CFA and are confined to properties only existed in the color domain. Therefore, they cannot be directly applied to multispectral demosaicking. The main challenges faced in multispectral demosaicking is how to design a generic algorithm that can handle the more diversified MSFA patterns, and how to improve performance with a coarser spatial resolution and a less degree of spectral correlation. In this paper, we present a binary tree based generic demosaicking method. Two metrics are used to evaluate the generic algorithm, including the root mean-square error (RMSE) for reconstruction performance and the classification accuracy for target discrimination performance. Experimental results show that the demosaicked images present low RMSE (less than 7) and comparable classification performance as original images. These results support that MSFA technique can be applied to multispectral imaging with unique advantages}, number={11}, journal={IEEE TRANSACTIONS ON IMAGE PROCESSING}, author={Miao, Lidan and Qi, Hairong and Ramanath, Rajeev and Snyder, Wesley E.}, year={2006}, month={Nov}, pages={3550–3558} }
 @article{karacali_ramanath_snyder_2004, title={A comparative analysis of structural risk minimization by support vector machines and nearest neighbor rule}, volume={25}, ISSN={["1872-7344"]}, DOI={10.1016/j.patrec.2003.09.002}, abstractNote={Support vector machines (SVMs) are by far the most sophisticated and powerful classifiers available today. However, this robustness and novelty in approach come at a large computational cost. On the other hand, nearest neighbor (NN) classifiers provide a simple yet robust approach that is guaranteed to converge to a result. In this paper, we present a technique that combines these two classifiers by adopting a NN rule-based structural risk minimization classifier. Using synthetic and real data, the classification technique is shown to be more robust to kernel conditions with a significantly lower computational cost than conventional SVMs. Consequently, the proposed method provides a powerful alternative to SVMs in applications where computation time and accuracy are of prime importance. Experimental results indicate that the NNSRM formulation is not only computationally less expensive, but also much more robust to varying data representations than SVMs.}, number={1}, journal={PATTERN RECOGNITION LETTERS}, author={Karacali, B and Ramanath, R and Snyder, WE}, year={2004}, month={Jan}, pages={63–71} }
 @article{qi_snyder_2004, title={Infrared imaging learns from camera industry}, volume={40}, number={7}, journal={Laser Focus World}, author={Qi, H. R. and Snyder, W. E.}, year={2004}, pages={78-} }
 @article{karacali_snyder_2004, title={Noise reduction in surface reconstruction from a given gradient field}, volume={60}, ISSN={["1573-1405"]}, DOI={10.1023/B:VISI.0000027788.50090.b6}, number={1}, journal={INTERNATIONAL JOURNAL OF COMPUTER VISION}, author={Karacali, B and Snyder, W}, year={2004}, month={Oct}, pages={25–44} }
 @article{ramanath_kuehni_snyder_hinks_2004, title={Spectral spaces and color spaces}, volume={29}, ISSN={["1520-6378"]}, DOI={10.1002/col.10211}, abstractNote={Abstract}, number={1}, journal={COLOR RESEARCH AND APPLICATION}, author={Ramanath, R and Kuehni, RG and Snyder, WE and Hinks, D}, year={2004}, month={Feb}, pages={29–37} }
 @article{ramanath_snyder_2003, title={Adaptive demosaicking}, volume={12}, ISSN={["1017-9909"]}, DOI={10.1117/1.1606459}, abstractNote={the . ; ac Abstract. Digital still color cameras sample the visible spectrum using an array of color filters overlaid on a CCD, such that each pixel samples only one color band. The resulting mosaic of color samples is processed to produce a high-resolution color image, such that a value of a color band not sampled at a certain location is estimated from its neighbors. This is often referred to as ‘‘demosaicking.’’ The human retina has a similar structure, although the distribution of cones is not as regular. Motivated by the human visual system, we propose an adaptive demosaicking technique in the framework of bilateral filtering. This approach provides us with a means to denoise, sharpen, and demosaic the image simultaneously. The proposed method, along with a variety of existing demosaicking strategies, are run on synthetic images and real-world images for comparative purposes. A recently proposed image comparison measure geared specifically toward demosaicking has also been applied to these images to provide a performance measure. © 2003 SPIE and IS&T. [DOI: 10.1117/1.1606459]}, number={4}, journal={JOURNAL OF ELECTRONIC IMAGING}, author={Ramanath, R and Snyder, WE}, year={2003}, month={Oct}, pages={633–642} }
 @article{karacali_snyder_2003, title={Reconstructing discontinuous surfaces from a given gradient field using partial integrability}, volume={92}, ISSN={["1077-3142"]}, DOI={10.1016/S1077-3142(03)00095-X}, abstractNote={This paper describes an adaptive surface reconstruction method from a given gradient field that allows discontinuities in the solution. We first formalize a vector space projection technique to reconstruct a surface with a uniformly integrable gradient field that corresponds to the minimum norm solution in the gradient space over discrete imaging settings. Next, we generalize this technique to reconstruct minimum norm solution surfaces with partially integrable gradient fields, where partial integrability is characterized adaptively from the given gradient field using multi-scale gradient space expansions. The simulations on synthesized and real data using block processing techniques indicate that the proposed method provides fast and reliable surface reconstruction through accurate characterization of embedded partial integrability in a given gradient field.}, number={1}, journal={COMPUTER VISION AND IMAGE UNDERSTANDING}, author={Karacali, B and Snyder, W}, year={2003}, month={Oct}, pages={78–111} }
 @article{ramanath_snyder_2002, title={Demosaicking as a bilateral filtering process}, volume={4667}, ISBN={["0-8194-4407-3"]}, ISSN={["0277-786X"]}, DOI={10.1117/12.467984}, abstractNote={Digital Still Color Cameras sample the visible spectrum using an array of color filters overlaid on a CCD such that each pixel samples only one color band. The resulting mosaic of color samples is processed to produce a high resolution color image such that a value of a color band not sampled at a certain location is estimated from its neighbors. This is often referred to as 'demosaicking.' In this paper, we approach the process of demosaicking as a bilateral filtering process which is a combination of spatial domain filtering and filtering based on similarity measures. Bilateral filtering smooths images while preserving edges by means of nonlinear combinations of neighboring image pixel values. A bilateral filter can enforce similarity metrics (such as squared error or error in the CIELAB space) between neighbors while performing the typical filtering operations. We have implemented a variety of kernel combinations while performing demosaicking. This approach provides us with a means to denoise, sharpen and demosaic the image simultaneously. We thus have the ability to represent demosaicking algorithms as spatial convolutions. The proposed method along with a variety of existing demosaicking strategies are run on synthetic images and real-world images for comparative purposes.}, journal={IMAGE PROCESSING: ALGORITHMS AND SYSTEMS}, author={Ramanath, R and Snyder, WE}, year={2002}, pages={236–244} }
 @article{ramanath_snyder_bilbro_sander_2002, title={Demosaicking methods for Bayer color arrays}, volume={11}, ISSN={["1560-229X"]}, DOI={10.1117/1.1484495}, abstractNote={Digital Still Color Cameras sample the color spectrum using a monolithic array of color filters overlaid on a charge coupled device array such that each pixel samples only one color band. The resulting mosaic of color samples is processed to produce a high resolution color image such that the values of the color bands not sampled at a certain location are estimated from its neighbors. This process is often referred to as demosaicking. This paper introduces and compares a few commonly used demosaicking methods using error metrics like mean squared error in the RGB color space and perceived error in the CIELAB color space. © 2002 SPIE and IS&T.}, number={3}, journal={JOURNAL OF ELECTRONIC IMAGING}, author={Ramanath, R and Snyder, WE and Bilbro, GL and Sander, WA}, year={2002}, month={Jul}, pages={306–315} }
 @inbook{ramanath_snyder_hinks_2002, title={Image comparison measure for digital still color cameras}, volume={1}, booktitle={2002 International Conference on Image Processing: proceedings: ICIP: 22-25 September, 2002, Rochester Riverside Convention Center, Rochester, New York, USA: Vol. 1}, publisher={Piscataway, NJ: IEEE}, author={Ramanath, A. R and Snyder, B. W. and Hinks, C. D.}, year={2002}, pages={629–632} }
 @article{qi_snyder_marchette_2000, title={Efficient approach to segment man-made targets from unmanned aerial vehicle imagery}, volume={39}, number={5}, journal={Optical Engineering (Redondo Beach, Calif.)}, author={Qi, H. R. and Snyder, W. E. and Marchette, D.}, year={2000}, pages={1267–1274} }
 @article{snyder_qi_elliott_head_wang_2000, title={Increasing the effective resolution of thermal infrared images - An algorithm based on mean-field annealing that also removes noise and preserves image}, volume={19}, ISSN={["1937-4186"]}, DOI={10.1109/51.844382}, abstractNote={Thermal infrared (TIR) imaging is recognized as the most efficient technique for the study of skin temperature distribution. In specific diseases, characteristic changes can be measured from target anatomical sites. In this way, objective noninvasive investigations can be of diagnostic value. TIR imaging of the breast for breast cancer risk assessment is an example. Although TIR imaging possesses the advantages of being noninvasive, risk free, and considerably less expensive, it suffers the disadvantage of a lack of resolution due to blur compounded by rather high levels of noise. A maximum a posteriori probability (MAP) image restoration philosophy is proposed to solve this problem of resolution. The objective is three-fold: to increase the resolution of the measured image by using a type of 2:1 zooming; to remove the noise; and simultaneously to preserve the detail of features, including, in particular, the sharpness of edges.}, number={3}, journal={IEEE ENGINEERING IN MEDICINE AND BIOLOGY MAGAZINE}, author={Snyder, WE and Qi, HR and Elliott, RL and Head, JF and Wang, CX}, year={2000}, pages={63–70} }
 @misc{bilbro_snyder_zilic_2000, title={Systems and methods for using diffraction patterns to determine radiation intensity values for areas between and along adjacent sensors of compound sensor arrays}, volume={6,021,241}, number={2000 Feb. 1}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={Bilbro, G. L. and Snyder, W. E. and Zilic, A.}, year={2000} }
 @misc{bilbro_snyder_zilic_1999, title={Compound image sensor array having staggered array of tapered optical fiber bundles}, volume={5,974,215}, number={1999 Oct. 26}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={Bilbro, G. L. and Snyder, W. E. and Zilic, A.}, year={1999} }
 @article{qi_snyder_1999, title={Content-based image retrieval in picture archiving and communications systems}, volume={12}, ISSN={["1618-727X"]}, DOI={10.1007/BF03168763}, abstractNote={We propose the concept of content-based image retrieval (CBIR) and demonstrate its potential use in picture archival and communication system (PACS). We address the importance of image retrieval in PACS and highlight the drawbacks existing in traditional textual-based retrieval. We use a digital mammogram database as our testing data to illustrate the idea of CBIR, where retrieval is carried out based on object shape, size, and brightness histogram. With a user-supplied query image, the system can find images with similar characteristics from the archive, and return them along with the corresponding ancillary data, which may provide a valuable reference for radiologists in a new case study. Furthermore, CBIR can perform like a consultant in emergencies when radiologists are not available. We also show that content-based retrieval is a more natural approach to man-machine communication.}, number={2}, journal={JOURNAL OF DIGITAL IMAGING}, author={Qi, HR and Snyder, WE}, year={1999}, month={May}, pages={81–83} }
 @article{han_snyder_bilbro_1998, title={Discontinuity-preserving vector smoothing of multivariate MR images using vector mean field annealing}, volume={9}, ISSN={["0924-9907"]}, DOI={10.1023/A:1026415719566}, number={3}, journal={JOURNAL OF MATHEMATICAL IMAGING AND VISION}, author={Han, YS and Snyder, WE and Bilbro, GL}, year={1998}, month={Nov}, pages={199–212} }
 @article{dai_snyder_bilbro_williams_cowan_1998, title={Left-ventricle boundary detection from nuclear medicine images}, volume={11}, ISSN={["0897-1889"]}, DOI={10.1007/BF03168721}, abstractNote={We present here a new algorithm for segmentation of nuclear medicine images to detect the left-ventricle (LV) boundary. In this article, other image segmentation techniques, such as edge detection and region growing, are also compared and evaluated. In the edge detection approach, we explored the relationship between the LV boundary characteristics in nuclear medicine images and their radial orientations: we observed that no single brightness function (eg, maximum of first or second derivative) is sufficient to identify the boundary in every direction. In the region growing approach, several criteria, including intensity change, gradient magnitude change, gradient direction change, and running mean differences, were tested. We found that none of these criteria alone was sufficient to successfully detect the LV boundary. Then we proposed a simple but successful region growing method—Contour-Modified Region Growing (CMRG). CMRG is an easy-to-use, robust, and rapid image segmentation procedure. Based on our experiments, this method seems to perform quite well in comparison to other automated methods that we have tested because of its ability to handle the problems of both low signal-to-noise ratios (SNR) as well as low image contrast without any assumptions about the shape of the left ventricle.}, number={1}, journal={JOURNAL OF DIGITAL IMAGING}, author={Dai, XL and Snyder, WE and Bilbro, GL and Williams, R and Cowan, R}, year={1998}, month={Feb}, pages={10–20} }
 @article{wang_snyder_bilbro_santago_1998, title={Performance evaluation of filtered backprojection reconstruction and iterative reconstruction methods for PET images}, volume={28}, ISSN={["0010-4825"]}, DOI={10.1016/S0010-4825(97)00031-0}, abstractNote={The filtered backprojection (FBP) algorithm and statistical model based iterative algorithms such as the maximum likelihood (ML) reconstruction or the maximum a posteriori (MAP) reconstruction are the two major classes of tomographic reconstruction methods. The FBP method is widely used in clinical setting while iterative methods have attracted research interests in the past decade. In this paper we studied the performance of the FBP, the ML and the MAP methods using simulated projection data. The experiment showed that the MAP algorithm generated superior image quality in terms of the bias, the variance, and the average mean squared error (MSE) measures.}, number={1}, journal={COMPUTERS IN BIOLOGY AND MEDICINE}, author={Wang, CX and Snyder, WE and Bilbro, G and Santago, P}, year={1998}, month={Jan}, pages={13–25} }