Conventional analysis of a cervical histology image, such a pap smear or a biopsy sample, is performed by an expert
pathologist manually. This involves inspecting the sample for cellular level abnormalities and determining the spread of
the abnormalities. Cancer is graded based on the spread of the abnormal cells. This is a tedious, subjective and time-consuming
process with considerable variations in diagnosis between the experts. This paper presents a computer aided
decision support system (CADSS) tool to help the pathologists in their examination of the cervical cancer biopsies. The
main aim of the proposed CADSS system is to identify abnormalities and quantify cancer grading in a systematic and
repeatable manner. The paper proposes three different methods which presents and compares the results using 475
images of cervical biopsies which include normal, three stages of pre cancer, and malignant cases.
This paper will explore various components of an effective CADSS; image acquisition, pre-processing, segmentation,
feature extraction, classification, grading and disease identification. Cervical histological images are captured using a
digital microscope. The images are captured in sufficient resolution to retain enough information for effective
classification. Histology images of cervical biopsies consist of three major sections; background, stroma and squamous
epithelium. Most diagnostic information are contained within the epithelium region. This paper will present two levels of
segmentations; global (macro) and local (micro). At the global level the squamous epithelium is separated from the
background and stroma. At the local or cellular level, the nuclei and cytoplasm are segmented for further analysis. Image
features that influence the pathologists’ decision during the analysis and classification of a cervical biopsy are the
nuclei’s shape and spread; the ratio of the areas of nuclei and cytoplasm as well as the texture and spread of the
abnormalities. Similar features are extracted towards the automated classification process. This paper will present
various feature extraction methods including colour, shape and texture using Gabor wavelet as well as various quantative
metrics. Generated features are used to classify cells or regions into normal and abnormal categories. Following the
classification process, the cancer is graded based on the spread of the abnormal cells. This paper will present the results
of the grading process with five stages of the cancer spectrum.
Haptic Modeling of textile has attracted significant interest over the last decade. In spite of extensive research, no generic
system has been proposed. The previous work mainly assumes that textile has a 2D planar structure. They also require
time-consuming measurement of textile properties in construction of the mechanical model. A novel approach for haptic
modeling of textile is proposed to overcome the existing shortcomings. The method is generic, assumes a 3D structure
for the textile, and deploys computational intelligence to estimate the mechanical properties of textile. The approach is
designed primarily for display of textile artifacts in museums. The haptic model is constructed by superimposing the
mechanical model of textile over its geometrical model. Digital image processing is applied to the still image of textile to
identify its pattern and structure through a fuzzy rule-base algorithm. The 3D geometric model of the artifact is
automatically generated in VRML based on the identified pattern and structure obtained from the textile image. Selected
mechanical properties of the textile are estimated by an artificial neural network; deploying the textile geometric
characteristics and yarn properties as inputs. The estimated mechanical properties are then deployed in the construction
of the textile mechanical model. The proposed system is introduced and the developed algorithms are described. The
validation of method indicates the feasibility of the approach and its superiority to other haptic modeling algorithms.
KEYWORDS: 3D modeling, Fuzzy logic, Haptic technology, Algorithm development, Systems modeling, Detection and tracking algorithms, Pattern recognition, Modeling, Data modeling, Visual process modeling
Geometric modeling and haptic rendering of textile has attracted significant interest over the last decade. A haptic representation is created by adding the physical properties of an object to its geometric configuration. While research has been conducted into geometric modeling of fabric, current systems require time-consuming manual recognition of textile specifications and data entry. The development of a generic approach for construction of the 3D geometric model of a woven textile is pursued in this work. The geometric model would be superimposed by a haptic model in the future work. The focus at this stage is on hand-woven textile artifacts for display in museums. A fuzzy rule based algorithm is applied to the still images of the artifacts to generate the 3D model. The derived model is exported as a 3D VRML model of the textile for visual representation and haptic rendering. An overview of the approach is provided and the developed algorithm is described. The approach is validated by applying the algorithm to different textile samples and comparing the produced models with the actual structure and pattern of the samples.
This paper focuses on simulating image processing algorithms and exploring issues related to reducing high resolution images to 25 x 25 pixels suitable for the retinal implant. Field of view (FoV) is explored, and a novel method of virtual eye movement discussed. Several issues beyond the normal model of human vision are addressed through context based processing.
This paper presents a novel multiresolution image segmentation method based on the discrete wavelet transform
and Markov Random Field (MRF) modelling. A major contribution of this work is to add spatial scalability
to the segmentation algorithm producing the same segmentation pattern at different resolutions. This property
makes it applicable for scalable object-based wavelet coding. To optimize segmentation at all resolutions of the
wavelet pyramid, with scalability constraint, a multiresolution analysis is incorporated into the objective function
of the MRF segmentation algorithm. Examining the corresponding pixels at different resolutions simultaneously
enables the algorithm to directly segment the images in the YUV or similar color spaces where luminance is in
full resolution and chrominance components are at half resolution. In addition to spatial scalability, the proposed
algorithm outperforms the standard single and multiresolution segmentation algorithms, in both objective
and subjective tests, yielding an effective segmentation that particularly supports scalable object-based wavelet
coding.
A decision support system has been developed to assist the radiologist during mammogram classification. In this paper,
mass identification and segmentation methods are discussed in brief. Fuzzy region-growing techniques are applied to
effectively segment the tumour candidate from surrounding breast tissue. Boundary extraction is implemented using a
unit vector rotating about the mass core. The focus of this work is on the feature extraction and classification processes.
Important information relating to the malignancy of a mass may be derived from its morphological properties. Mass
shape and boundary roughness are primary features used in this research to discriminate between the two types of
lesions. A subset from thirteen shape descriptors is input to a binary decision tree classifier that provides a final diagnosis
of tumour malignancy. Features that combine to produce the most accurate result in distinguishing between malignant
and benign lesions include: spiculation index, zero crossings, boundary roughness index and area-to-perimeter ratio.
Using this method, a classification result of high sensitivity and specificity is achieved, with false-positive and falsenegative
rates of 9.3% and 0% respectively.
In this paper, a novel wavelet-morphology method for the detection of mass abnormalities in digital mammograms is presented. The new scheme utilizes the feature extraction capability of the wavelet transform followed by a novel recursive-enhancement morphology algorithm to detect the masses. A morphology-based segmentation algorithm is finally applied to the enhanced image to separate the mass from the normal breast tissues. This technique outlines the shape of the region of interest (mass in mammograms). Tests results have confirmed the efficacy of the technique in automated detection of abnormalities in wavelet based compressed mammograms.
The latest trend in computer assisted mammogram analysis is reviewed and two new methods developed by the authors for automatic detection of microcalcifications (MCs) are presented. The first method is based on wavelet neurone feature detectors and ART classifiers while the second method utilized fuzzy rules for detection and grading of MCs.
A new method of texture classification comprising two processing stages, namely a low-level evolutionary feature extraction based on Gabor wavelets and a high-level neural network based pattern recognition, is proposed. The design of these stages is motivated by the processes involved in the human visual system: low-level receptors responsible for early vision processing and the high-level cognition. Gabor wavelets are used as extractors of "lowlevel" features that feed the feature-adaptive adaptive resonance theory (ART) neural network acting as a high-level "cognitive system." The novelty of the model developed in this paper lies in the use of a self-organizing input layer to the fuzzy ART. Evaluation of the model is performed by using natural textures, and results obtained show that the developed model is capable of performing the texture recognition task effectively. Applications of the developed model include the study of artificial vision systems motivated by the human visual system model.
Receptive field profiles of simple cells in the visual cortex have been shown to resemble even- symmetric or odd-symmetric Gabor filters. Computational models employed in the analysis of textures have been motivated by two-dimensional Gabor functions arranged in a multi-channel architecture. More recently wavelets have emerged as a powerful tool for non-stationary signal analysis capable of encoding scale-space information efficiently. A multi-resolution implementation in the form of a dyadic decomposition of the signal of interest has been popularized by many researchers. In this paper, Gabor wavelet configured in a 'rosette' fashion is used as a multi-channel filter-bank feature extractor for texture classification. The 'rosette' spans 360 degrees of orientation and covers frequencies from dc. In the proposed algorithm, the texture images are decomposed by the Gabor wavelet configuration and the feature vectors corresponding to the mean of the outputs of the multi-channel filters extracted. A minimum distance classifier is used in the classification procedure. As a comparison the Gabor filter has been used to classify the same texture images from the Brodatz album and the results indicate the superior discriminatory characteristics of the Gabor wavelet. With the test images used it can be concluded that the Gabor wavelet model is a better approximation of the cortical cell receptive field profiles.
Vision guided mobile robot navigation is complex and requires analysis of tremendous amounts of information in real time. In order to simplify the task and reduce the amount of information, human preattentive mechanism can be adapted [Nag90]. During the preattentive search the scene is analyzed rapidly but in sufficient detail for the attention to be focused on the `area of interest.' The `area of interest' can further be scrutinized in more detail for recognition purposes. This `area of interest' can be a text message to facilitate navigation. Gabor filters and an automated turning mechanism are used to isolate the `area of interest.' These regions are subsequently processed with optimal spatial resolution for perception tasks. This method has clear advantages over the global operators in that, after an initial search, it scans each region of interest with optimum resolution. This reduces the volume of information for recognition stages and ensures that no region is over or under estimated.
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