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ABSTRACT: Histogram specification has been successfully used in digital image processing over the years. Mainly used as an image enhancement technique, methods such as histogram equalization (HE) can yield good contrast with almost no effort in terms of inputs to the algorithm or the computational time required. More elaborate histograms can take on problems faced by HE at the expense of having to define the final histograms in innovative ways that may require some extra processing time but are nevertheless fast enough to be considered for real-time applications. This paper proposes a new technique for specifying a histogram to enhance the image contrast. To further evidence our faith on histogram specification techniques, we also discuss methods to modify images, e.g., to help segmentation approaches. Thus, as advocates of these techniques, we would like to emphasize the flexibility of this image processing approach to do more than enhancing images.
IEEE Transactions on Instrumentation and Measurement 06/2011; · 1.21 Impact Factor
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ABSTRACT: Breast Microwave Radar(BMR) is a novel imaging modality that is capable of producing high contrast images and can detect tumors of at least 4mm. To properly visualize the responses from the breast structures, BMR data sets must be reconstructed. In this paper, a real time BMR image formation technique is proposed. This approach is based on the use of a Single Instruction Multiple Thread(SIMT) interpolation method. By using this programming model, the proposed approach can be implemented on General Purpose Graphic Processing Unit (GPGPU) platform to speed up the reconstruction process. The proposed method yielded promising results when applied to simulated data sets obtained using anatomically accurate numeric phantoms. In average, the proposed approach yielded speed increases of one order of magnitude compared to its CPU counterpart, and two orders of magnitude with respect to current BMR reconstruction techniques.
Image Processing (ICIP), 2010 17th IEEE International Conference on; 10/2010
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ABSTRACT: Electrical Impedance Tomography (EIT) has been proposed as an alternative modality for breast imaging. Current EIT reconstruction algorithms are based in optimization procedures that aim to minimize the difference between the recorded data and a set of candidate scenarios. However, these methods produce images with diffused edges, as sharp structures are penalized by current regularization techniques. In this paper, a novel edge preserving EIT reconstruction method is proposed. This technique uses a priori information obtained from Breast Microwave Radar images to estimate the location of the dense breast regions. Then, the monotonicity of the impedance matrix of the collected data is used to reconstruct a profile of the tissue distribution in the breast region. The proposed method yielded promising results when applied to numeric phantoms generated from Magnetic Resonance Imaging datasets.
Engineering in Medicine and Biology Society (EMBC), 2010 Annual International Conference of the IEEE; 10/2010
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ABSTRACT: Currently, prostate cancer is the third leading cause of cancer-related deaths among men in North America. As with many others types of cancer, early detection and treatment greatly increases the patient's chance of survival. Combined Magnetic Resonance Imaging and Spectroscopic Imaging (MRI/MRSI) techniques have became a reliable tool for early stage prostate cancer detection. Nevertheless, their performance is strongly affected by the determination of the region of interest (ROI) prior to data acquisition process. The process of executing prostate MRI/MRSI techniques can be significantly enhanced by segmenting the whole prostate. A novel method for segmentation of the prostate in MRI datasets is presented. This method exploits the different behavior presented by signal singularities and noise in the wavelet domain in order to accurately detect the borders around the prostate. The prostate contour is then traced by using a set of spatially variant rules that are based on prior knowledge about the general shape of the prostate. The proposed method yielded promising results when applied to clinical datasets.
Engineering in Medicine and Biology Society (EMBC), 2010 Annual International Conference of the IEEE; 10/2010
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ABSTRACT: Radar meets ultrasound; this article covers a new approach to testing underground power cable insulation in a nondestructive fashion. The possibilities and future potential of the combined use of two different imaging technologies are discussed.
IEEE Electrical Insulation Magazine 07/2010; · 1.33 Impact Factor
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ABSTRACT: Breast cancer is the leading cause of cancer related deaths in women between the ages of 15 and 54, and the second cause of cancer death in women the 55 to 74 age range. In recent years, Breast microwave imaging (BMI) has shown its potential as a promising breast cancer detection technique. This imaging technology is based on the electrical characteristic differences that exist between normal and malignant breast tissues at the microwave frequency range. A novel reconstruction approach for the formation of 2D BMI models is proposed in this paper. This technique uses the phase differences introduced during the collection of target responses in order to determine the correct spatial location of the different structures that constitute the final image. The proposed method yielded promising results when applied to simulated data sets obtained from magnetic resonance images (MRI).
Engineering in Medicine and Biology Society, 2009. EMBC 2009. Annual International Conference of the IEEE; 10/2009
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ABSTRACT: In recent years, breast microwave imaging (BMI) has shown its potential as a promising breast cancer detection technique. This imaging technology is based on the electrical characteristic differences that exist between normal and malignant breast tissues at the microwave frequency range. A promising image formation technique for BMI radar based approaches is wavefront reconstruction. In this approach, the image quality and execution time of this image formation technique is strongly affected by the interpolation method that is used. In this paper, a performance study between three popular interpolation techniques, nearest neighbor, linear and cubic splines, for breast microwave radar imaging is presented. The performance of the evaluated techniques was assessed using numeric phantoms obtained from Magnetic Resonance Imaging (MRI) data sets. The results of this study indicate that linear interpolation techniques are the most suitable choices based on their computational cost, and the focal quality and signal to noise of their resulting images.
Engineering in Medicine and Biology Society, 2009. EMBC 2009. Annual International Conference of the IEEE; 10/2009
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ABSTRACT: Radar imaging using an ISAR system requires the estimation of the targets kinematic parameters in order to be used for motion compensation. A focused and legible image requires this step. Some of the popular methods that perform this compensation are based on an entropy metric. This metric is relatively simple to use but requires a lot of computations (i.e. it can be quite slow) and it can also yield a false estimation due to local minima. In this work the authors introduced the use of a conditional entropy metric that helps with the problem of local minima and also propose the use of working with low resolution images to increase the speed of the estimation. Results are shown using real data.
Radar Systems, 2007 IET International Conference on; 11/2007
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P. Lombardo,
L Teng,
B. Flores, D. Flores-Tapia,
G Thomas,
G Chen,
X Liu,
Z Zhou,
H. Callow,
R. Hansen,
T. Sparr,
J. Groen,
M.A. Gaffar,
W. Nel,
M. Martorella,
F. Berizzi,
J. Palmer,
B. Haywood,
B. Bates
Radar Systems, 2007. RADAR 2007. The Institution of Engineering and Technology International Conference on; 11/2007
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H. Rohling,
L Teng,
G Thomas, D. Flores-Tapia,
S. Pistorius,
M. Cherniakov,
M. Gashinova,
Antoniou,
L.Y. Daniel,
C. Hu,
V. Sizov,
M. Trinkle,
D. Gray,
B. Ferguson,
B. Brautigam,
M. Schwerdt,
B. Doring,
A.N. Sharp,
B.D. Bates
Radar Systems, 2007. RADAR 2007. The Institution of Engineering and Technology International Conference on; 11/2007
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ABSTRACT: This paper presents a novel method for Heart Sound (HS) cancellation from Lung Sound (LS) records. The method uses the multiscale product of the wavelet coefficients of the original signal to detect HS-included segments. Once the HS segments are identified, the method removes them from the wavelet coefficients at every level and estimates the created gaps by using a set of linear prediction filters. It is shown that if the segment to be predicted is stationary, a final record with no audible artifacts such as clicks can be reconstructed using this approach. The results were promising for HS removal from LS records and showed no hampering of the main components of the LS. The results were confirmed both qualitatively by listening to the reconstructed signal and quantitatively by spectral analysis
IEEE Transactions on Biomedical Engineering 03/2007; · 2.28 Impact Factor
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ABSTRACT: Currently, breast cancer is the leading cause of cancer death in women between the ages of 15 and 54, and the second cause of cancer death in women 55 to 74. In recent years, Breast Microwave Imagery (BMI) has shown its potential as a promising breast cancer detection technique. This imaging technology is based on the electrical characteristic differences that exist between normal and malignant breast tissues at the microwave frequency range. A novel reconstruction approach for the formation of 3D BMI models is proposed in this paper. This technique uses the phase differences introduced during the collection of target responses in order to determine the correct spatial location of the different scatterers that constitute the final image. The proposed method yielded promising results when applied to simulated data
Engineering in Medicine and Biology Society, 2006. EMBS '06. 28th Annual International Conference of the IEEE; 10/2006
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ABSTRACT: This paper addresses a two-dimensional inverse scattering method with a combination of tomography and radar methods for breast cancer detection. In order to rapidly construct high resolution images displaying the location, size, permittivity and conductivity of malignant tumors inside the body, the collected reflection from the scattered fields present in the scan area is segmented and their associated dielectric property maps are calculated. The dielectric profiles are obtained by using a technique that combines frequency domain finite difference time domain (FD)<sup>2</sup>TD analysis with genetic algorithm (GA) optimization. The applications of the proposed method can vary from medical imaging to nondestructive testing of materials and structures. The proposed technique yielded promising results when applied to simulated data
Engineering in Medicine and Biology Society, 2006. EMBS '06. 28th Annual International Conference of the IEEE; 10/2006
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ABSTRACT: Imaging of buried objects using subsurface microwave technology can result in images with numerous undesirable artifacts due in part to noise and multipath scattering. In order to alleviate the problem of multipath scattering, the authors propose the combined use of monostatic and bistatic systems. Focusing both images and compensating the bistatic system enables us to place the direct path scatterers at the same position as in the monostatic case. A multiplication of the final images will attenuate the scatterers that are formed by multiple reflections and will therefore reduce artifacts. Results are shown using simulations in which the signatures of several point scatterers overlap for the direct reflections and where the multipath signatures do not; thus allowing the multiplication to enhance the final image.
Computational Advances in Multi-Sensor Adaptive Processing, 2005 1st IEEE International Workshop on; 01/2006
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ABSTRACT: In order to obtain a high resolution inverse synthetic aperture radar image, the kinematic parameters of the target must be estimated in order to focus the image. Entropy metrics have been a popular technique to achieve good estimates. For subsurface radar imagery, the parameter needed for focusing purposes is the permittivity of the medium. Unlike airborne radar, subsurface back scattering occurs in a noisy environment and the use of this traditional metric does not yield good results. In this paper, the authors proposed the use of a denoising technique and a conditional entropy metric that overcomes the difficulties encounter when using an entropy calculation as a focal quality indicator
Applied Electromagnetics and Communications, 2005. ICECom 2005. 18th International Conference on; 11/2005
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ABSTRACT: Breast cancer incidence in women has increased from one in twenty in 1960 to one in eight today. Despite significant progress on traditional breast imaging and cancer detection techniques, such as X-ray mammography, limitations do persist and other alternative methods have been explored. One of such methods is breast microwave imaging (BMI). This paper presents the effect of the irradiation source beamwidth on the focus quality of BMI when wavefront reconstruction techniques are used to form the images. The data is assumed to be collected using a cylindrical scan trajectory. The theoretical basis is validated using simulated data
Applied Electromagnetics and Communications, 2005. ICECom 2005. 18th International Conference on; 11/2005
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ABSTRACT: Canada is one of the major exporters of wheat in the world. The quality of these exports is well known and factors such as lack of insect infestation are very important. The use of thermal images for subsequent analysis of temperatures profiles for grain classification and insect detection is a method under investigation. This paper presents an approach for automatic image segmentation of the wheat kernels based on the combined use of wavelet analysis and pulse coupled neural networks. It is shown that using wavelets as a preprocessing technique yields a consistent accurate segmentation in terms of the iteration number in which the network yields reliable edges of the wheat kernels. Subsequent analysis of these segmentations can determine internal qualities such as infestations.
Image Processing, 2007. ICIP 2007. IEEE International Conference on;
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Progress in Electromagnetics Research-Pier. 118:461-486.
