Engineering Commons^™

Device Structure Effects On Electrical Crosstalk In Backwall Illuminated Cmos Compatible Photodiode Arrays, Paul Vernon Jansz

Theses : Honours

This research has made a comparative investigated of crosstalk in backside illuminated and frontside illuminated single junction photodiode and vertical double junction photodiode CMOS compatible pixels, using a commercial 2D device simulation package, SEMICAD DEVICE (1994). Comparison of pixel total, electron and hole quantum efficiency response and Absorption Volume data is undertaken. This is so that the underlying carrier drift-diffusion dynamics responsible for optimal pixel response resolution may be qualitatively understood, allowing prediction of even more optimal photodiode pixel configurations. The effect of varying the double junction and single junction photodiode pixel's geometry on response resolution is considered. Only for …

Video Compression Using Wavelets And Hierarchical Motion Estimation, Andrew Peter Byrne

Theses : Honours

This thesis investigates the benefits and the significant compression that can be obtained from data that has been decomposed using a wavelet transform. A video compression algorithm was developed that employs the wavelet transform and a hierarchical motion estimation algorithm which itself utilises benefits of the wavelet transform. Using MATLAB, a popular software tool for matrix based computation and analysis, several functions were developed which together formed the video compression algorithm. A variety of tests were conducted on a sample video sequence to ascertain the strengths and weaknesses of the techniques employed. The results, although not the same as the …

Vhdl Design And Simulation For Embedded Zerotree Wavelet Quantisation, Hung Huynh

Theses : Honours

This thesis discusses a highly effective still image compression algorithm – The Embedded Zerotree Wavelets coding technique, as it is called. This technique is simple but achieves a remarkable result. The image is wavelet-transformed, symbolically coded and successive quantised, therefore the compression and transmission/storage saving can be achieved by utilising the structure of zerotree. The algorithm was first proposed by Jerome M. Shapiro in 1993, however to minimise the memory usage and speeding up the EZW processor, a Depth First Search method is used to transverse across the image rather than Breadth First Search method as initially discussed in Shapiro's …

A Simplified Approach To Reduce Blocking And Ringing Artifacts In Transform-Coded Images, Jianping Hu

Dissertations and Theses

Presently Block-based Discrete Cosine Transform (BDCT) image coding techniques are widely used in image and video compression applications such as JPEG and MPEG. At a moderate bit rate, BDCT is usually a quite satisfactory solution to most of practical coding applications. However, for high rate compression it produces noticeable blocking and ringing artifacts in the decompressed image. It has been an active research area for a decade for reducing these artifacts. In this thesis, a novel post-processing algorithm is proposed to remove the blocking and ringing artifacts at low bit rate. It is non-iterative and uses both spatial and transform …

Contour Extraction From Hvem Image Of Microvessel Using Active Contour Models, Manping Xiao

Theses

This thesis reports the research results on automatic contour extraction from high voltage electron microscope (HVEM) image of thick cross section montages of small blood vessels. The previous work on this subject, which was based on the conventional edge detection operations combined with edge linking, has proven inadequate to describe the inner structural compartments of microvessels. In this thesis, an active contour model (commonly referred to as "Snakes") has been applied to advance the previous work. Active contour models have proven themselves to be a powerful and flexible paradigm for many problems in image understanding, especially in contour extraction from …

Blur Identification And Restoration Of Images Of Coronary Microvessel, Kuen Tak Wong

Theses

The objective of this research was to identify the blur characteristics of the blurred images of the rat coronary microvessel, and the information of the blur characteristics was used to restore the blurred images. The blur characteristics were analyzed by using the image power cepstrum. The Wiener filter was implemented to restore the images. There were two types of point spread functions proposed and studied for the restoration. They were: defocus blur PSF and motion blur PSF. The images were transferred from HP A900 system to an AVS workstation. The images were processed and manipulated by the AVS, and showed …

Optical Flow Determination And Motion Analysis, Qian Wang

Theses

Optical flow, also known as image flow, is of fundamental importance in the processing of image sequences. Various approaches to determine optical flow have been proposed --- others continue to appear. Using several sets of real image sequences, here, the results of three different approaches to the the determination of optical flow are reported, the approaches are the Gradient-based approach, the Correlation-based approach and the Correlation-feedback approach. The comparisons are primarily empirical, and they show that the performance of these different algorithms differs significantly among the different image sequences, indicating that there does not exists one superior algorithm which could …

Comparing Techniques Of Mapping Pyramid Algorithms Onto The Hypercube : A Case Study For The Connection Machine, Muhammad Ali Siddiqui

Theses

The pyramid structure is most widely used for low-level and intermediate-level image processing and computer vision because of its efficient support of both local and global operations. However, the cost of pyramid computers (PC) may be very high. They also do not support the efficient implementation of the majority of the scientific algorithms. In contrast, the hypercube network has widely been used in the field of parallel processing because it offers a high degree of fault tolerance, a small diameter and rich interconnection structure that permits fast communication at a reasonable cost. Thus, several algorithms have been developed for the …

Developing Image Processing Tools In X Window System, Xin Zhang

Dissertations and Theses

The X Window System is an industry-standard software system which facilitates programmers to develop portable graphical user interfaces. This thesis describes an image processing tool developed under the X Window System. A multiwindow image display software with image editing and improvement functions is developed. The software has four modules: environment generation, image creation, image editing and image improvement.

The environment generation module creates working windows, scrollbars, dialogbox and pulldown menu buttons, and tracks mouse cursor positions. The working windows are three adjacent windows allowing display of three different images simultaneously. The dialogbox provides an interface between the user and the …

Low To Medium Level Image Processing For A Mobile Robot, Cecilia H. Espinosa

Dissertations and Theses

The use of visual perception in autonomous mobile systems was approached with caution by mobile robot developers because of the high computational cost and huge memory requirements of most image processing operations. When used, the image processing is implemented on multiprocessors or complex and expensive systems, thereby requiring the robot to be wired or radio controlled from the computer system base.

Decomposition Of Measured Contours Into Geometric Features For Dimensional Inspection, Devaraj Rajkumar

Dissertations and Theses

Image processing systems used in Vision Assisted Dimensional Inspection usually output a set of boundary pixels representing the part edges. This boundary information must be divided into several subsets representing the various edges of the actual object, so that comparisons with the nominal part can be made.

The purpose of this project is to devise a method to divide the set of pixels obtained from the image processing system into subsets of pixels. Each of these subsets represent an edge in the contour of the actual object. This method must also detect transition points between the adjacent features. This project …

A Comparison Of Integrated And Differential Estimates Of Flourescent Intensity Profiles Using Digital Video Image Analysis, Langfang Wu

Theses

The dynamics of macromolecular transport across microvascular walls in the hamster cheek pouch have previously been studied by other investigators using fluorescence intravital microscopy. Fluorescein Isothiocyanate labeled Dextrans (FITC-Dx) of 20,000, and 70,000 molecular weight (FITC-Dx-20 and FITC- Dx-70) were used as macromolecular probes. Values of fluorescent intensity were previously recorded on videotape as a function of distance perpendicular to leaking vessels over a period of about 2.5 hr to allow for tracer equilibration in the interstitial space. In this study, these videotapes were played back frame-by-frame and 215x130-pixel windows around each leaking vessel were selected for further analysis of …

A Comparative Study Of The Performance Of Various Image Analysis Methods For Dimensional Inspection With Vision Systems, Ralf Heinrich Koeppe

Dissertations and Theses

Dimensional inspection with Vision Systems requires a careful selection of image analysis methods in order to obtain accurate information about the geometry of the parts to be measured.

The purpose of this project is to study, implement and compare different image evaluation methods and to show their strengths and weaknesses with respect to dimensional inspection. Emphasis is made on the inspection of circular features. The criteria of comparison for these methods are discussed. Using synthetically generated images, various analysis methods are compared and conclusions for their use are drawn. Results of the comparison show that the selection of a method …

Invariant Pattern Recognition Algorithm Using The Hough Transform, Duwang Li

Dissertations and Theses

A new algorithm is proposed which uses the Hough Transform to recognize two dimensional objects independent of their orientations, sizes and locations. The binary image of an object is represented by a set of straight lines. Features of the straight lines, namely the lengths and the angles of their normals, their lengths and the end point positions are extracted using the Hough Transform. A data structure for the extracted lines is constructed so that it is efficient to match the features of the lines of one object to those of another object, and determine if one object is a rotated …

Three-Level Block Truncation Coding, Deborah Ann Lee

Retrospective Theses and Dissertations

Block Truncation Coding (BTC) techniques, to date, utilize a two-level image block code. This thesis presents and studies a new BTC method employing a three-level image coding technique. This new method is applied to actual image frames and compared with other well-known block truncation coding techniques.

The method separates an image into disjoint, rectangular regions of fixed size and finds the highest and lowest pixel values of each. Using these values, the image block pixel value range is calculated and divided into three equal sections. The individual image block pixels are then quantized according to the region into which their …

Parallel Approximate String Matching Applied To Occluded Object Recognition, David Smith

Dissertations and Theses

This thesis develops an algorithm for approximate string matching and applies it to the problem of partially occluded object recognition. The algorithm measures the similarity of differing strings by scanning for matching substrings between strings. The length and number of matching substrings determines the amount of similarity. A classification algorithm is developed using the approximate string matching algorithm for the identification and classification of objects. A previously developed method of shape description is used for object representation.

Quadtree-Based Processing Of Digital Images, Ramin Naderi

Dissertations and Theses

Image representation plays an important role in image processing applications, which usually. contain a huge amount of data. An image is a two-dimensional array of points, and each point contains information (eg: color). A 1024 by 1024 pixel image occupies 1 mega byte of space in the main memory. In actual circumstances 2 to 3 mega bytes of space are needed to facilitate the various image processing tasks. Large amounts of secondary memory are also required to hold various data sets.

In this thesis, two different operations on the quadtree are presented.

There are, in general, two types of data …

Two New Parallel Processors For Real Time Classification Of 3-D Moving Objects And Quad Tree Generation, Farjam Majd

Dissertations and Theses

Two related image processing problems are addressed in this thesis. First, the problem of identification of 3-D objects in real time is explored. An algorithm to solve this problem and a hardware system for parallel implementation of this algorithm are proposed. The classification scheme is based on the "Invariant Numerical Shape Modeling" (INSM) algorithm originally developed for 2-D pattern recognition such as alphanumeric characters. This algorithm is then extended to 3-D and is used for general 3-D object identification. The hardware system is an SIMD parallel processor, designed in bit slice fashion for expandability. It consists of a library of …