When geographical distance poses as a barrier, telepathology is designed to offer pathologists the opportunity to replicate their normal activities by using an alternative means of practice. The rapid progression in technology has greatly influenced the appeal of telepathology and its use in multiple domains. To that point, telepathology systems help to afford teleconsultation services for remote locations, improve the workload distribution in clinical environments, measure quality assurance, and also enhance educational programs. While telepathology is an attractive method to many potential users, the resource requirements for digitizing microscopic specimens have hindered widespread adoption. The use of image compression is extremely critical to help advance the pervasiveness of digital images in pathology. For this research, we characterize two different methods that we use to assess compression of pathology images. Our first method is characterized by the fact that image quality is human-based and completely subjective in terms of interpretation. Our second method is characterized by the fact that image analysis is introduced by using machine-based interpretation to provide objective results. Additionally, the objective outcomes from the image analysis may also be used to help confirm tumor classification. With these two methods in mind, the purpose of this dissertation is to quantify the effects of image compression on data interpretation as seen by human experts and a computerized algorithm for use in telepathology.

Thesis (Ph.D)--Literature, Communication, and Culture, Georgia Institute of Technology, 2010. / Committee Chair: Mazalek, Alexandra; Committee Member: Bolter, Jay; Committee Member: Knospel, Kenneth; Committee Member: Murray, Janet; Committee Member: Winegarden, Claudia Rebola. Part of the SMARTech Electronic Thesis and Dissertation Collection.

Šiame darbe pateikiama trumpa efektyvaus vaizdų kodavimo metodų ir požiūrių apžvalga. Susipažįstama su diskrečiosiomis (Haaro, Daubechies) bangelių transformacijomis bei įvertinamos jų specifinės savybės: diskretaus bangelių spektro koeficiento sąsaja su vaizdo fragmentu, nulinių medžių egzistavimas spektre. Darbo tikslas – įvertinus diskrečiųjų bangelių transformacijos savybes, algoritmizuoti, realizuoti ir ištirti vieną perspektyviausių progresyviojo skaitmeninių vaizdų kodavimo algoritmų EZW (Embedded-Zerotree-Wavelet). / This paper discusses specific properties of the discrete orthogonal wavelet transform, namely: relationships between the wavelet coefficients and image fragments, existence of zerotrees in the discrete wavelet spectrum of an image, etc. In parallels, the progressive image encoding idea and an efficient image encoding/decoding algorithm EZW (Embedded-Zerotree-Wavelet), based on the discrete wavelet (Haar, Daubechies) transform, are presented. Some preliminary experimental analysis results are discussed.

Digital image steganography has been made relevant by the rapid increase in media sharing over the Internet and has thus experienced a renaissance. This dissertation starts with a discussion of the role of modern digital image steganography and cell-based digital image stego-systems which are the focus of this work. Of particular interest is the fact that cell-based stego-systems have good security properties but relatively poor embedding capacity. The main research problem is stated as the development of an approach to improve embedding capacity in cell-based systems. The dissertation then tracks the development of digital image stego-systems from spatial and naïve to transform-based and complex, providing the context within which cell-based systems have emerged and re-states the research problem more specifically as the development of an approach to determine more efficient data embedding and error coding schemes in cell-based stego-systems to improve embedding capacity while maintaining security. The dissertation goes on to describe the traditional application of data handling procedures particularly relating to the likely eventuality of JPEG compression of the image containing the hidden information (i.e. stego-image) and proposes a new approach. The approach involves defining a different channel model, empirically determining channel characteristics and using them in conjunction with error coding systems and security selection criteria to find data handling parameters that optimise embedding capacity in each channel. Using these techniques and some reasoning regarding likely cover image size and content, image-global error coding is also determined in order to keep the image error rate below 1% while maximising embedding capacity. The performance of these new data handling schemes is tested within cell-based systems. Security of these systems is shown to be maintained with an up to 7 times improvement in embedding capacity. Additionally, up to 10% of embedding capacity can be achieved versus simple LSB embedding. The 1% image error rate is also confirmed to be upheld. The dissertation ends with a summary of the major points in each chapter and some suggestions of future work stemming from this research. / Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2012.

Radiology is rapidly changing in the 21st century and globally there is a transition of radiology departments to digital imaging technology. The major challenge confronting radiology practices is to obtain cost savings and productivity gains once PACS is established. The purpose of the study is to undertake an incremental cost analysis of PACS compared to a conventional radiology department. Cost savings of the system was also determined in terms of productivity gains. An incremental cost analysis for Chest X-rays, CT Brain scans with and without contrast, MRI Brain scans with and without contrast was performed. The overall incremental cost between a PACS site and a conventional radiography site was determined in the study. The net present value technique was also determined to evaluate the capital budgeting requirements for both systems. The incremental costs for capital, RIS and image production for the PACS as well as the conventional system were performed. The incremental costs for both capital and RIS show an increase. In contrast, the incremental PACS image cost shows a reduction. This study provides a number of South African Radiology Departments which plan to introduce PACS in the near future with a bench mark for the financial implications incurred during the implementation phase. It assists other facilities in deciding on implementing PACS and contributes to the development of methodologies within the South African context. / Thesis (M.Med.Sc.)-University of KwaZulu-Natal, 2012

Thesis (Ph. D.)--State University of New York at Binghamton, Computer Science Department, 2006. / Includes bibliographical references.

Thesis (Ph. D.)--University of California, San Diego, 2006. / Title from first page of PDF file (viewed September 20, 2006). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references (p. 238-244).

Σκοπός αυτής της διπλωματικής εργασίας είναι να παρουσιαστούν μερικές από τις πιο αξιοσημείωτες τεχνικές για την Ισοστάθμιση των Χρωματικών Αποκλίσεων σε ψηφιακή φωτογραφία. Αρχικά δίνονται κάποια γενικά στοιχεία για την ψηφιακή φωτογραφία, τα χρωματικά μοντέλα και συγκεκριμένα το μοντέλο RGB, την ψηφιακή καταγραφή της εικόνας καθώς και οι στοιχειώδεις λειτουργίες της ανθρώπινης όρασης. Στο δεύτερο κεφάλαιο αναλύονται οι βασικές έννοιες της χρωματικής απόκλισης και παραθέτονται με ορισμούς και παραδείγματα τα δυο βασικά είδη χρωματικών αποκλίσεων που είναι η αξονική χρωματική απόκλιση (longitudinal or axial aberration) και η πλευρική χρωματική απόκλιση (transverse or lateral aberration). Το τρίτο κεφάλαιο είναι μια αναλυτική περιγραφή τριών μεθόδων ισοστάθμισης/περιορισμού των χρωματικών αποκλίσεων. Δίνεται η θεωρητική ανάλυση κάθε μιας, η περιγραφή της πειραματικής διαδικασίας που ακολουθείται καθώς επίσης και τα συμπεράσματα που προκύπτουν από την εφαρμογή τους. Τέλος, στο τέταρτο κεφάλαιο δίνονται δυο διαφορετικοί τύποι σχεδιασμού φακού Gauss, που αποβάλλουν αποτελεσματικά την αρχική χρωματική παρέκκλιση χρησιμοποιώντας έναν αποδοτικό γενετικό αλγόριθμο (GA). / Aim of this Diploma Thesis Project is to present the most remarkable techniques of the Compensation of Chromatic Aberrations appeared in digital images. Initially are given certain general elements for the digital photograph, the chromatic models and especially the RGB model, the digital imaging process and the elementary operations of the human sight system. In the second chapter the basic significations of chromatic aberrations are analysed. Also, definitions and examples support the two basic types of chromatic distortions that are the longitudinal or axial aberrations and the transverse or lateral aberrations. The third chapter is a complete description of three methods of the compensation of chromatic distortions. It is given the theoretical analysis for each one, the full description of the experimental process that is followed and the conclusions that result from their application. Finally, in the last chapter, two different types of Gauss lens design, which effectively eliminate primary chromatic aberration, are presented using an efficient genetic algorithm (GA).

Αντικείμενο της παρούσας διπλωματικής εργασίας είναι η δημιουργία πανοράματος από υποθαλάσσιες ψηφιακές φωτογραφίες που λαμβάνονται περιστρέφοντας μια φωτογραφική μηχανή στηριγμένη σε τρίποδο. Αναπτύσσεται μία μέθοδος δημιουργίας πανοράματος βασισμένη στην αντιστοίχιση σημείων των εικόνων. Η υλοποίηση πραγματοποιείται σε περιβάλλον Matlab. Αρχικά γίνεται μια εισαγωγή στις μεθόδους αποκατάστασης ενός περιβάλλοντος από εικόνες και στη συνέχεια παρουσιάζονται οι βασικές μέθοδοι δημιουργίας πανοραμάτων. Η διαδικασία της υλοποίησης περιλαμβάνει την ευθυγράμμιση των φωτογραφιών, με αντιστοίχιση των κοινών σημείων τους χρησιμοποιώντας μια μέθοδο ετεροσυσχέτισης και την συρραφή τμημάτων των εικόνων για τη δημιουργία του πανοράματος. Η αντιστοίχιση γίνεται πρώτα υπολογίζοντας μόνο την οριζόντια μετατόπιση και στη συνέχεια υπολογίζοντας την οριζόντια και την κάθετη μετατόπιση. Στο τέλος αναπτύσσεται μια μέθοδος υπολογισμού της τρισδιάστατης μετατόπισης μιας κάμερας που κινείται ευθύγραμμα με κατεύθυνση προς το αντικείμενο / --

Orientador: Milton Terumitsu Sogabe / Banca: Pelópidas Cypriano de Oliveira / Banca: Silvia Laurentz / Resumo: Este trabalho reúne análises sobre as imagens digitais com questões estruturais e poéticas do movimento, fazendo um levantamento histórico e artístico desde os primeiros experimentos em cronofotografia, até as manifestações atuais, do universo digital, que incorporam o movimento como temática. A imagem digital tratada não é de cunho sintético, mas sim que passou por algum processo de captura analógica, por meio de câmeras, e após isso, foi digitalizada. A partir daí, a pesquisa reflete as transformações estéticas e sinestéticas que as imagens podem sofrer de acordo com as possibilidades oferecidas pela tecnologia digital. Procuramos discutir os processos e precedimentos artísticos sob a luz desse caráter tecnológico, em que as imagens ganham novas formas dinâmicas e novos padrões de movimento. Buscamos incluir os principais fatores que são singulares ao universo digital e permitem concepções artísticas inovadoras através das novas mídias surgidas. Entre as características estão a convergência, desmaterialização, ubiqüidade e a replicabilidade dos remixes e samplers. Três obras foram discutidas com maior profundidade por oferecerem suporte conceitural, visual e nova proposta estética: Stop Motion Studies (David Crawford), Soft Cinema (Lev Manovich) e as Live Images (Luiz Duva). Durante a pesquisa, a autora também elaborou três obras construídas em momentos distintos, que acompanhavam os questionamentos feitos ao longo do processo: convergência, gradeativa e passagens. As obras sugerem um estreitamento intenso entre arte e pesquisa, pratica e teoria, no intuito de atingir complexidade sobre o tema, para contribuir com estudos contemporâneos sobre as manifestações artísticas nas novas mídias. / Abstract: This work analyses the digital under the structural and poetical issues of the movement, making a historical and artistic retrospective since the first experiments in cronophotography, to the current manisfestations of the digital universe, that incorporate the movement as thema. The treated digital image is not asynthetic matrix, but the one that passed for some process of analogical capture by cameras and then digitalized. Further on, the research reflects about the aesthetic and synesthesic transformations that images can receive with possibilities offered by the digital technology. We look for debate the processes and artistic procedures and its techological features, when the images gain new dynamic forms and new standards of movement. We try to include the main factors that are singular to the digital universe and allow innovative artistic comceptions through the new appeared medias. Some of the features are the convergence, dematerialization, ubiquity and the replicability of remixes and samplers. Three artistic creation had been deeply analysed because of its conceptual visual and new aesthetic proposal support: Stop Motion Studies (David Crawford), Soft Cinema (Lev Manovich) and the Live Images (Luiz Duva). During this work, the author also elaboreted three creactions built in different times, that accompany the debates made throughout the process: Convergência, Gradeativa and Passagens. These creations suggest an intense relationship between aty and research, practical and theory in intention to reach complexity on the subject, to contribute with contemporaneous studies on artistic manisfestations in the new medias. / Mestre