A computational visual saliency model for images.

Human eyes receive an enormous amount of information from the visual world. It is highly difficult to simultaneously process this excessive information for the human brain. Hence the human visual system will selectively process the incoming information by attending only the relevant regions of interest in a scene. Visual saliency characterises some parts of a scene that appears to stand out from its neighbouring regions and attracts the human gaze. Modelling saliency-based visual attention has been an active research area in recent years. Saliency models have found vital importance in many areas of computer vision tasks such as image and video compression, object segmentation, target tracking, remote sensing and robotics. Many of these applications deal with high-resolution images and real-time videos and it is a challenge to process this excessive amount of information with limited computational resources. Employing saliency models in these applications will limit the processing of irrelevant information and further will improve their efficiency and performance. Therefore, a saliency model with good prediction accuracy and low computation time is highly essential. This thesis presents a low-computation wavelet-based visual saliency model designed to predict the regions of human eye fixations in images. The proposed model uses two-channel information luminance (Y) and chrominance (Cr) in YCbCr colour space for saliency computation. These two channels are decomposed to their lowest resolution using two-dimensional Discrete Wavelet Transform (DWT) to extract the local contrast features at multiple scales. The extracted local contrast features are integrated at multiple levels using a two-dimensional entropy-based feature combination scheme to derive a combined map. The combined map is normalized and enhanced using natural logarithm transformation to derive a final saliency map. The performance of the model has been evaluated qualitatively and quantitatively using two large benchmark image datasets. The experimental results show that the proposed model has achieved better prediction accuracy both qualitatively and quantitatively with a significant reduction in computation time when compared to the existing benchmark models. It has achieved nearly 25% computational savings when compared to the benchmark model with the lowest computation time

Evaluation of automated organ segmentation for total-body PET-CT

The ability to diagnose rapidly and accurately and treat patients is substantially facilitated by medical images. Radiologists' visual assessment of medical images is crucial to their study. Segmenting images for diagnostic purposes is a crucial step in the medical imaging process. The purpose of medical image segmentation is to locate and isolate ‘Regions of Interest’ (ROI) within a medical image. Several medical uses rely on this procedure, including diagnosis, patient management, and medical study. Medical image segmentation has applications beyond just diagnosis and treatment planning. Quantitative information from medical images can be extracted by image segmentation and employed in the research of new diagnostic and treatment procedures. In addition, image segmentation is a critical procedure in several programs for image processing, including image fusion and registration. In order to construct a single, high-resolution, high-contrast image of an item or organ from several images, a process called "image registration" is used. A more complete picture of the patient's anatomy can be obtained through image fusion, which entails integrating numerous images from different modalities such as computed tomography (CT) and Magnetic resonance imaging (MRI). Once images are obtained using imaging technologies, they go through post-processing procedures before being analyzed. One of the primary and essential steps in post-processing is image segmentation, which involves dividing the images into parts and utilizing only the relevant sections for analysis. This project explores various imaging technologies and tools that can be utilized for image segmentation. Many open-source imaging tools are available for segmenting medical images across various applications. The objective of this study is to use the Jaccard index to evaluate the degree of similarity between the segmentations produced by various medical image visualization and analysis programs

A Review on Classification of White Blood Cells Using Machine Learning Models

The machine learning (ML) and deep learning (DL) models contribute to exceptional medical image analysis improvement. The models enhance the prediction and improve the accuracy by prediction and classification. It helps the hematologist to diagnose the blood cancer and brain tumor based on calculations and facts. This review focuses on an in-depth analysis of modern techniques applied in the domain of medical image analysis of white blood cell classification. For this review, the methodologies are discussed that have used blood smear images, magnetic resonance imaging (MRI), X-rays, and similar medical imaging domains. The main impact of this review is to present a detailed analysis of machine learning techniques applied for the classification of white blood cells (WBCs). This analysis provides valuable insight, such as the most widely used techniques and best-performing white blood cell classification methods. It was found that in recent decades researchers have been using ML and DL for white blood cell classification, but there are still some challenges. 1) Availability of the dataset is the main challenge, and it could be resolved using data augmentation techniques. 2) Medical training of researchers is recommended to help them understand the structure of white blood cells and select appropriate classification models. 3) Advanced DL networks such as Generative Adversarial Networks, R-CNN, Fast R-CNN, and faster R-CNN can also be used in future techniques.Comment: 23 page

FEATURE SPACE UNIDIMENSIONAL PROJECTIONS FOR SCATTERPLOTS

Multidimensional projection techniques are important tools employed in data set exploration and data mining tasks. The data set instances are described in a multidimensional space and projection techniques can be employed to reduce the data set dimensionality and to aid the visualization of instances relations in a computer screen. Usually, the whole multidimensional space is projected, i.e., if it is composed by distinct feature spaces they are handled as a unique feature space. This work proposes an alternative approach dealing with multidimensional spaces as distinct feature spaces, so multidimensional projections can reduce the dimensionality of each feature space into unidimensional spaces and be visualized by a scatter plot -- each unidimensional space will be associated with an axis. Our approach was compared with the traditional way that projects the whole multidimensional space (feature spaces) into the bi-dimensional space. Experiments with different data sets were performed to evaluate which approach better preserves the groups cohesion on the projected space, revealing our approach with good results

Image segmentation and pattern classification using support vector machines

Image segmentation and pattern classification have long been important topics in computer science research. Image segmentation is one of the basic and challenging lower-level image processing tasks. Feature extraction, feature reduction, and classifier design based on selected features are the three essential issues for the pattern classification problem. In this dissertation, an automatic Seeded Region Growing (SRG) algorithm for color image segmentation is developed. In the SRG algorithm, the initial seeds are automatically determined. An adaptive morphological edge-linking algorithm to fill in the gaps between edge segments is designed. Broken edges are extended along their slope directions by using the adaptive dilation operation with suitably sized elliptical structuring elements. The size and orientation of the structuring element are adjusted according to local properties. For feature reduction, an improved feature reduction method in input and feature spaces using Support Vector Machines (SVMs) is developed. In the input space, a subset of input features is selected by the ranking of their contributions to the decision function. In the feature space, features are ranked according to the weighted support vectors in each dimension. For object detection, a fast face detection system using SVMs is designed. Twoeye patterns are first detected using a linear SVM, so that most of the background can be eliminated quickly. Two-layer 2nd-degree polynomial SVMs are trained for further face verification. The detection process is implemented directly in feature space, which leads to a faster SVM. By training a two-layer SVM, higher classification rates can be achieved. For active learning, an improved incremental training algorithm for SVMs is developed. Instead of selecting training samples randomly, the k-mean clustering algorithm is applied to collect the initial set of training samples. In active query, a weight is assigned to each sample according to its distance to the current separating hyperplane and the confidence factor. The confidence factor, calculated from the upper bounds of SVM errors, is used to indicate the degree of closeness of the current separating hyperplane to the optimal solution

Artificial neural network and its applications in quality process control, document recognition and biomedical imaging

In computer-vision based system a digital image obtained by a digital camera would usually have 24-bit color image. The analysis of an image with that many levels might require complicated image processing techniques and higher computational costs. But in real-time application, where a part has to be inspected within a few milliseconds, either we have to reduce the image to a more manageable number of gray levels, usually two levels (binary image), and at the same time retain all necessary features of the original image or develop a complicated technique. A binary image can be obtained by thresholding the original image into two levels. Therefore, thresholding of a given image into binary image is a necessary step for most image analysis and recognition techniques. In this thesis, we have studied the effectiveness of using artificial neural network (ANN) in pharmaceutical, document recognition and biomedical imaging applications for image thresholding and classification purposes. Finally, we have developed edge-based, ANN-based and region-growing based image thresholding techniques to extract low contrast objects of interest and classify them into respective classes in those applications. Real-time quality inspection of gelatin capsules in pharmaceutical applications is an important issue from the point of view of industry\u27s productivity and competitiveness. Computer vision-based automatic quality inspection and controller system is one of the solutions to this problem. Machine vision systems provide quality control and real-time feedback for industrial processes, overcoming physical limitations and subjective judgment of humans. In this thesis, we have developed an image processing system using edge-based image thresholding techniques for quality inspection that satisfy the industrial requirements in pharmaceutical applications to pass the accepted and rejected capsules. In document recognition application, success of OCR mostly depends on the quality of the thresholded image. Non-uniform illumination, low contrast and complex background make it challenging in this application. In this thesis, optimal parameters for ANN-based local thresholding approach for gray scale composite document image with non-uniform background is proposed. An exhaustive search was conducted to select the optimal features and found that pixel value, mean and entropy are the most significant features at window size 3x3 in this application. For other applications, it might be different, but the procedure to find the optimal parameters is same. The average recognition rate 99.25% shows that the proposed 3 features at window size 3x3 are optimal in terms of recognition rate and PSNR compare to the ANN-based thresholding technique with different parameters presented in the literature. In biomedical imaging application, breast cancer continues to be a public health problem. In this thesis we presented a computer aided diagnosis (CAD) system for mass detection and classification in digitized mammograms, which performs mass detection on regions of interest (ROI) followed by the benign-malignant classification on detected masses. Three layers ANN with seven features is proposed for classifying the marked regions into benign and malignant and 90.91% sensitivity and 83.87% specificity is achieved that is very much promising compare to the radiologist\u27s sensitivity 75%

Food Dimension Estimation from A Single Image Using Structured Lights

Two-thirds the population in the United States of America are overweight or obese. The annual medical expenditures attributable to obesity may be as high as $215 billion per year. Obesity has been linked to many types of diseases, including cancer, type 2 diabetes, cardiovascular diseases, respiratory diseases, stroke and birth defects. Deaths related to obesity are estimated at 300,000 each year in the United States. In order to understand the etiology of the obesity epidemic and develop effective weight management methods for obese patients, accurate dietary data is an essential requirement. However, the current dietary assessment methods, which depend on self-reported data by the respondents, have an estimated 20% to 50% discrepancy from the intake. This large error severely affects obesity research.The recent rapid advances in electrical engineering and information technology fields have provided sophisticated devices and intelligent algorithms for dietary assessment. Considering portability and battery-life, systems installed with a single camera have the advantages of low cost, space saving, and low power consumption. Although severalmethods have been proposed to estimate food quantities and dimensions, many of these methods cannot be used in practice because of their inconvenience, and the requirement of calibration andmaintenance. In this dissertation, we present several approaches to food dimensional estimation using two types of structured lights. These approaches are low in costand power consumption, and suitable for small and portable image acquisition devices.Our first design uses structured laser beams as reference lights. Three identical laser modules are structured to form an equilateraltriangle on the plane orthogonal to the camera optical axis. A new method based on orthogonallinear regression is proposed to release restrictions on the laserbeams, so that the precision requirement for equilateral triangle can be relaxed. Based on the perspective projectiongeometry, intersections of structured laser beams andperspective projection rays are estimated, which construct a spatial planecontaining the projection of the objects of interest. The dimensions of the objects on theobserved plane are then calculated. In the second design, an LED diode is used as a reference light. A new algorithm is developed to estimate the object plane using the deformation of the observed ellipse.In order to provide a precise system calibration between the structured lights and the camera, an orthogonal linear regression method is proposed to calibrate the structured lights. Characteristics of the reference features are investigated. A color-based thresholding method is proposed to segment features. An ellipse fitting method is used to extract feature parameters. The extraction results of our algorithms are very close to those manually performed by human.Several experiments are performed to test our designs using both artificial and real food. Our experimental results show an average estimation error of lessthan 10%

Computer vision for microscopy diagnosis of malaria

This paper reviews computer vision and image analysis studies aiming at automated diagnosis or screening of malaria infection in microscope images of thin blood film smears. Existing works interpret the diagnosis problem differently or propose partial solutions to the problem. A critique of these works is furnished. In addition, a general pattern recognition framework to perform diagnosis, which includes image acquisition, pre-processing, segmentation, and pattern classification components, is described. The open problems are addressed and a perspective of the future work for realization of automated microscopy diagnosis of malaria is provided

CHARACTERIZATION OF ENGINEERED SURFACES

In the recent years there has been an increasing interest in manufacturing products where surface topography plays a functional role. These surfaces are called engineered surfaces and are used in a variety of industries like semi conductor, data storage, micro- optics, MEMS etc. Engineered products are designed, manufactured and inspected to meet a variety of specifications such as size, position, geometry and surface finish to control the physical, chemical, optical and electrical properties of the surface. As the manufacturing industry strive towards shrinking form factor resulting in miniaturization of surface features, measurement of such micro and nanometer scale surfaces is becoming more challenging. Great strides have been made in the area of instrumentation to capture surface data, but the area of algorithms and procedures to determine form, size and orientation information of surface features still lacks the advancement needed to support the characterization requirements of R&D and high volume manufacturing. This dissertation addresses the development of fast and intelligent surface scanning algorithms and methodologies for engineered surfaces to determine form, size and orientation of significant surface features. Object recognition techniques are used to identify the surface features and CMM type fitting algorithms are applied to calculate the dimensions of the features. Recipes can be created to automate the characterization and process multiple features simultaneously. The developed methodologies are integrated into a surface analysis toolbox developed in MATLAB environment. The deployment of the developed application on the web is demonstrated