Esta tese se propõe examinar a poesia de John Donne (1572-1631) na perspectiva de um âmbito mais amplo de práticas representativas dos meios letrados das cortes do século XVII. Pressupondo a vigência de uma instituição retórica cujos preceitos condicionavam a prática poética, adota-se uma metodologia de pesquisa que flexibiliza os limites classificatórios da historiografia oitocentista posteriormente impostos aos poetas do século XVII. Assim, procede-se a uma análise retórico-poética da poesia de Donne, particularmente, mas também de seus coetâneos George Chapman, Fulke Greville, William Shakespeare e outros considerando os gêneros e estilos de suas composições, as espécies de agudeza que efetuavam, a adequação dos conceitos que formulavam como ornato dialético enigmático e a legibilidade que constituíam nas obras. Propõe-se uma investigação dos pressupostos doutrinários vigentes na época que significam as práticas representativas e as categorias que a envolvem, como a conceituação de que a poesia vernacular culta se define como prática de emulação da poesia greco-latina em seu elenco de autoridades; de que a preceituação vernacular analogamente se define como prática de emulação da preceitução antiga em seus postulados diversos; que a prática de emulação é ativa e não pressupõe cópia servil, mas variação dos argumentos de um mesmo lugar de invenção e variação do tópico elocutório, assumindo a versatilidade das operações retórico-poéticas como prova de engenho e arte. Tendo como força determinante a valoração do wit (engenho; ingenio; ingegno) nos meios letrados do século XVII, esta tese considera sempre que pode as práticas poéticas e preceptivas continentais, cruzando-as com suas contrapartes inglesas, buscando definir os critérios variados de recepção da poesia e os preceitos em uso que constituem a poética da agudeza. / This Ph.D. thesis examines the poetry of John Donne (1572-1631) in the light of the representative practices in the learned circles of 17th century courts. Presuming that there was an effective presence of a rhetorical institution at that time, which conditioned poetical production, I have adopted a critical methodology that displaces the classificatory limits of 19th century historiography later imposed on the poets of the early 17th century. I have specifically made a rhetorical-poetical analysis of the poetry of Donne, but also of George Chapman, Fulke Greville, William Shakespeare and others, considering the genres and the styles of their composition, the types of wit they used, the aptness of the conceits formulated as enigmatic dialectical ornaments, and the legibility of their works. I have also investigated the doctrinal conjectures current at the time which then signified the representative practices, such as the concept that cultivated vernacular poetry was defined as an emulation of Greek and Latin poetry; that the vernacular doctrines of rhetoric were also defined as emulation of ancient doctrines; and that the practice of emulation was an active force, and did not imply servile imitation, but rather a variation of the places of argument and the elocutory topic, taking on the diversity of rhetorical and poetical procedures as proof of wit and art. Taking as a determining force the value given to wit (engenho; ingenio; ingegno) in the learned circles of the early 17th century, this thesis also takes into consideration continental poetical and rhetorical practices, cross-examining them with English ones, in an attempt to define the diverse criteria of poetry reception and the precepts then extant which ultimately constituted the poetics of wit.

Esta tese se propõe examinar a poesia de John Donne (1572-1631) na perspectiva de um âmbito mais amplo de práticas representativas dos meios letrados das cortes do século XVII. Pressupondo a vigência de uma instituição retórica cujos preceitos condicionavam a prática poética, adota-se uma metodologia de pesquisa que flexibiliza os limites classificatórios da historiografia oitocentista posteriormente impostos aos poetas do século XVII. Assim, procede-se a uma análise retórico-poética da poesia de Donne, particularmente, mas também de seus coetâneos George Chapman, Fulke Greville, William Shakespeare e outros considerando os gêneros e estilos de suas composições, as espécies de agudeza que efetuavam, a adequação dos conceitos que formulavam como ornato dialético enigmático e a legibilidade que constituíam nas obras. Propõe-se uma investigação dos pressupostos doutrinários vigentes na época que significam as práticas representativas e as categorias que a envolvem, como a conceituação de que a poesia vernacular culta se define como prática de emulação da poesia greco-latina em seu elenco de autoridades; de que a preceituação vernacular analogamente se define como prática de emulação da preceitução antiga em seus postulados diversos; que a prática de emulação é ativa e não pressupõe cópia servil, mas variação dos argumentos de um mesmo lugar de invenção e variação do tópico elocutório, assumindo a versatilidade das operações retórico-poéticas como prova de engenho e arte. Tendo como força determinante a valoração do wit (engenho; ingenio; ingegno) nos meios letrados do século XVII, esta tese considera sempre que pode as práticas poéticas e preceptivas continentais, cruzando-as com suas contrapartes inglesas, buscando definir os critérios variados de recepção da poesia e os preceitos em uso que constituem a poética da agudeza. / This Ph.D. thesis examines the poetry of John Donne (1572-1631) in the light of the representative practices in the learned circles of 17th century courts. Presuming that there was an effective presence of a rhetorical institution at that time, which conditioned poetical production, I have adopted a critical methodology that displaces the classificatory limits of 19th century historiography later imposed on the poets of the early 17th century. I have specifically made a rhetorical-poetical analysis of the poetry of Donne, but also of George Chapman, Fulke Greville, William Shakespeare and others, considering the genres and the styles of their composition, the types of wit they used, the aptness of the conceits formulated as enigmatic dialectical ornaments, and the legibility of their works. I have also investigated the doctrinal conjectures current at the time which then signified the representative practices, such as the concept that cultivated vernacular poetry was defined as an emulation of Greek and Latin poetry; that the vernacular doctrines of rhetoric were also defined as emulation of ancient doctrines; and that the practice of emulation was an active force, and did not imply servile imitation, but rather a variation of the places of argument and the elocutory topic, taking on the diversity of rhetorical and poetical procedures as proof of wit and art. Taking as a determining force the value given to wit (engenho; ingenio; ingegno) in the learned circles of the early 17th century, this thesis also takes into consideration continental poetical and rhetorical practices, cross-examining them with English ones, in an attempt to define the diverse criteria of poetry reception and the precepts then extant which ultimately constituted the poetics of wit.

Microcirculation is defined as the blood flow in the smallest blood vessels. Laser speckle contrast imaging (LSCI) is a full field imaging technique that provides instantaneous 2-D perfusion maps of illuminated tissues based on speckle contrast. Perimed’s Perfusion Speckle Imager (PSI) is a medical device developed at Perimed AB that exploits LSCI to measure tissue blood perfusion. In this thesis work, a robust Autofocus (AF) algorithm for PSI was implemented. AF is a procedure to drive PSI camera to reach the depth of focus and acquire sharp images, that relies only on signal processing. Therefore, several Blind image sharpness assessment (BISA) methods, to judge the degree of image sharpness, were compared to choose which BISA method to incorporate in the algorithm. An optimized focus scanning technique was implemented to more efficiently find the depth of focus. When working with LSCI, speckle is a source of noise that destroys image content. Experiments were performed to study laser speckle filtration: digital filters were employed to attenuate the speckle noise that corrupted details in the acquired images. Finally, two methods to perform AF were provided. These procedures were proven practically with LED images. However, with laser source image information is corrupted by speckle despite the application of digital filters and AF remains a real challenge. Moreover, important hardware limitations require to be overcome to make the technique real-time. Focus motor speed should be higher to acquire images at different focus positions faster which could benefit the speed of the AF procedure and speckle filtration.

The ability of humans to perceive significant pattern and structure of an image is something which humans take for granted. We can recognize objects and patterns independent of changes in image contrast and illumination. In the past decades, it has been widely recognized in both biology and computer vision that phase contains critical information in characterizing the structures in images. Despite the importance of local phase information and its significant success in many computer vision and image processing applications, the coherence behavior of local phases at scale-space is not well understood. This thesis concentrates on developing an invariant image representation method based on local phase information. In particular, considerable effort is devoted to study the coherence relationship between local phases at different scales in the vicinity of image features and to develop robust methods to measure the strength of this relationship. A computational framework that computes local phase coherence (LPC) intensity with arbitrary selections in the number of coefficients, scales, as well as the scale ratios between them has been developed. Particularly, we formulate local phase prediction as an optimization problem, where the objective function computes the closeness between true local phase and the predicted phase by LPC. The proposed framework not only facilitates flexible and reliable computation of LPC, but also broadens the potentials of LPC in many applications. We demonstrate the potentials of LPC in a number of image processing applications. Firstly, we have developed a novel sharpness assessment algorithm, identified as LPC-Sharpness Index (LPC-SI), without referencing the original image. LPC-SI is tested using four subject-rated publicly-available image databases, which demonstrates competitive performance when compared with state-of-the-art algorithms. Secondly, a new fusion quality assessment algorithm has been developed to objectively assess the performance of existing fusion algorithms. Validations over our subject-rated multi-exposure multi-focus image database show good correlations between subjective ranking score and the proposed image fusion quality index. Thirdly, the invariant properties of LPC measure have been employed to solve image registration problem where inconsistency in intensity or contrast patterns are the major challenges. LPC map has been utilized to estimate image plane transformation by maximizing weighted mutual information objective function over a range of possible transformations. Finally, the disruption of phase coherence due to blurring process is employed in a multi-focus image fusion algorithm. The algorithm utilizes two activity measures, LPC as sharpness activity measure along with local energy as contrast activity measure. We show that combining these two activity measures result in notable performance improvement in achieving both maximal contrast and maximal sharpness simultaneously at each spatial location.

The ability of humans to perceive significant pattern and structure of an image is something which humans take for granted. We can recognize objects and patterns independent of changes in image contrast and illumination. In the past decades, it has been widely recognized in both biology and computer vision that phase contains critical information in characterizing the structures in images. Despite the importance of local phase information and its significant success in many computer vision and image processing applications, the coherence behavior of local phases at scale-space is not well understood. This thesis concentrates on developing an invariant image representation method based on local phase information. In particular, considerable effort is devoted to study the coherence relationship between local phases at different scales in the vicinity of image features and to develop robust methods to measure the strength of this relationship. A computational framework that computes local phase coherence (LPC) intensity with arbitrary selections in the number of coefficients, scales, as well as the scale ratios between them has been developed. Particularly, we formulate local phase prediction as an optimization problem, where the objective function computes the closeness between true local phase and the predicted phase by LPC. The proposed framework not only facilitates flexible and reliable computation of LPC, but also broadens the potentials of LPC in many applications. We demonstrate the potentials of LPC in a number of image processing applications. Firstly, we have developed a novel sharpness assessment algorithm, identified as LPC-Sharpness Index (LPC-SI), without referencing the original image. LPC-SI is tested using four subject-rated publicly-available image databases, which demonstrates competitive performance when compared with state-of-the-art algorithms. Secondly, a new fusion quality assessment algorithm has been developed to objectively assess the performance of existing fusion algorithms. Validations over our subject-rated multi-exposure multi-focus image database show good correlations between subjective ranking score and the proposed image fusion quality index. Thirdly, the invariant properties of LPC measure have been employed to solve image registration problem where inconsistency in intensity or contrast patterns are the major challenges. LPC map has been utilized to estimate image plane transformation by maximizing weighted mutual information objective function over a range of possible transformations. Finally, the disruption of phase coherence due to blurring process is employed in a multi-focus image fusion algorithm. The algorithm utilizes two activity measures, LPC as sharpness activity measure along with local energy as contrast activity measure. We show that combining these two activity measures result in notable performance improvement in achieving both maximal contrast and maximal sharpness simultaneously at each spatial location.

Dans de nombreux domaines tels que l’apprentissage statistique, la recherche opérationnelle ou encore la conception de circuits, une tâche est modélisée par un jeu de paramètres que l’on cherche à optimiser pour prendre la meilleure décision possible. Mathématiquement, le problème revient à minimiser une fonction de l’objectif recherché par des algorithmes itératifs. Le développement de ces derniers dépend alors de la géométrie de la fonction ou de la structure du problème. Dans une première partie, cette thèse étudie comment l’acuité d’une fonction autour de ses minima peut être exploitée par le redémarrage d’algorithmes classiques. Les schémas optimaux sont présentés pour des problèmes convexes généraux. Ils nécessitent cependant une description complète de la fonction, ce qui est rarement disponible. Des stratégies adaptatives sont donc développées et prouvées être quasi-optimales. Une analyse spécifique est ensuite conduite pour les problèmes parcimonieux qui cherchent des représentations compressées des variables du problème. Leur géométrie conique sous-jacente, qui décrit l’acuité de la fonction de l’objectif, se révèle contrôler à la fois la performance statistique du problème et l’efficacité des procédures d’optimisation par une seule quantité. Une seconde partie est dédiée aux problèmes d’apprentissage statistique. Ceux-ci effectuent une analyse prédictive de données à l’aide d’un large nombre d’exemples. Une approche générique est présentée pour à la fois résoudre le problème de prédiction et le simplifier en groupant soit les variables, les exemples ou les tâches. Des méthodes algorithmiques systématiques sont développées en analysant la géométrie induite par une partition des données. Une analyse théorique est finalement conduite lorsque les variables sont groupées par analogie avec les méthodes parcimonieuses. / In numerous fields such as machine learning, operational research or circuit design, a task is modeled by a set of parameters to be optimized in order to take the best possible decision. Formally, the problem amounts to minimize a function describing the desired objective with iterative algorithms. The development of these latter depends then on the characterization of the geometry of the function or the structure of the problem. In a first part, this thesis studies how sharpness of a function around its minimizers can be exploited by restarting classical algorithms. Optimal schemes are presented for general convex problems. They require however a complete description of the function that is rarely available. Adaptive strategies are therefore developed and shown to achieve nearly optimal rates. A specific analysis is then carried out for sparse problems that seek for compressed representation of the variables of the problem. Their underlying conic geometry, that describes sharpness of the objective, is shown to control both the statistical performance of the problem and the efficiency of dedicated optimization methods by a single quantity. A second part is dedicated to machine learning problems. These perform predictive analysis of data from large set of examples. A generic framework is presented to both solve the prediction problem and simplify it by grouping either features, samples or tasks. Systematic algorithmic approaches are developed by analyzing the geometry induced by partitions of the data. A theoretical analysis is then carried out for grouping features by analogy to sparse methods.

Das Ziel dieser Untersuchung ist es, Aspekte der Strukturqualität (technische Untersuchungs- und Bildqualität), Prozessqualität (Angemessenheit der Indikation) und der Ergebnisqualität (Richtigkeit der Befunderhebungen) von Röntgenaufnahmen aus der tierärztlichen Praxis zu erörtern und häufige Fehlerquellen festzustellen. Dazu werden alle Röntgenaufnahmen von Kleintieren, die im Zeitraum von Anfang Dezember 2003 bis Ende Dezember 2004 als Original in die Klinik für Kleintiere der Universität Leipzig gelangen auf praxisrelevante Merkmale der Struktur-, Prozess- und Ergebnisqualität hin untersucht. Die Ermittlung der Daten erfolgt auf subjektiver Grundlage anhand eines Befundbogens durch Konsensbeurteilung von zwei Unter-suchern. Zur Auswertung gelangen 1259 Röntgenaufnahmen aus 600 verschiedenen Untersuchungen. Diese Aufnahmen stammen zu 86,9 % aus den Bundesländern Sachsen, Sachsen-Anhalt und Thüringen von 216 verschiedenen Tierarztpraxen. 80,3 % der untersuchten Tiere sind Hunde, 18,9 % Katzen. In der Gesamtbeurteilung der Bildqualität erweisen sich 48,7 % der Aufnahmen ohne Bean-standung. 29,2 % zeigen geringfügige Mängel, 16,0 % sind bedingt diagnostisch geeignet und 6,1 % sind unzureichend. 22,1 % der ausgewerteten Aufnahmen sind somit mangelhaft. Sie weisen Defizite in der diagnostischen Eignung auf oder sind hierfür ungeeignet. Die wichtigsten Fehlerquellen der Strukturqualität sind Mängel der Lagerung und Projektion, des Bildkontrastes und der Bildschärfe. Abweichungen der Lagerung und Projektion, meist durch nicht winkelgerechte Lagerung des Patienten im Direktstrahl verursacht, sind mit 11,4 % aller Aufnahmen im Vergleich zu anderen Fehlerquellen relativ selten. Die Auswirkungen auf die diagnostische Eignung sind jedoch oft schwerwiegend: 69,9 % der von Mängeln in der Lagerung betroffenen Aufnahmen zeigen Einschränkungen hinsichtlich der diagnostischen Eignung. 33,3 % aller Aufnahmen weisen Abweichungen des Bildkontrastes auf. Die häufigste Ursache dafür ist der Umgang mit verbrauchter Entwicklerlösung, gefolgt von Unter- und Überbelichtung. Betrachtet man die Gesamtheit der Kontrastabweichungen kann festgestellt werden, dass 47,7 % auf Fehler in der Filmentwicklung zurückzuführen sind. Auswirkungen auf die Eignung zur Diagnosestellung sind weniger gravierend als bei Mängeln der Lagerung und Projektion: 35,1 % der von Kontrastabweichungen betroffenen Aufnahmen zeigen Einschränkungen des diagnosti-schen Nutzens. 23,0 % der Aufnahmen sind durch Abweichungen der Bildschärfe gekennzeichnet. Am häufigs-ten ist Bewegungsunschärfe (67,7 % der betroffenen Aufnahmen) zu ermitteln. Weiterhin wer-den oft Materialunschärfe und Unschärfe durch Streustrahlung beobachtet, die auf den falschen Umgang mit dem Streustrahlenraster und der Film-Folien-Kombination zurückzuführen sind. Die Auswirkungen auf die diagnostische Eignung zeigen, dass 29,6 % der Röntgenaufnahmen mit Abweichungen der Bildschärfe Einschränkungen des diagnostischen Nutzens nach sich ziehen. Artefakte, vor allem verursacht durch Kratzer, Risse oder Brüche in Film oder Folie sowie durch Verunreinigungen durch Entwickler-, Fixierlösung oder Wasser, sind bei 20,7 % aller Röntgen-aufnahmen zu finden. Einschränkungen der diagnostischen Eignung ergeben sich dadurch bei 1,2 % der analysierten Aufnahmen. Zur Untersuchung der Prozessqualität wird die Angemessenheit der Indikation ermittelt, die nach RöV § 2a für jede Röntgenaufnahme gegeben sein muss (ANON. 2003a). Eine absolute Indikation kann bei 94,7 % der ausgewerteten Aufnahmen festgestellt werden. Bei knapp der Hälfte aller Aufnahmen dieser Arbeit kann die Ergebnisqualität erörtert werden. Die gestellte radiologische Verdachtsdiagnose ist bei 85,5 % dieser Fälle medizinisch nachvoll-ziehbar. Aus den Ergebnissen dieser Arbeit lässt sich ableiten, dass ein wesentlicher Teil der vorkom-menden Mängel der Bildqualität auf ungenügende Sorgfalt bei der Anfertigung und Verarbeitung der Röntgenaufnahme zurückzuführen ist. Allerdings liegen auch Defizite bei der Interpretation der gewonnenen Information durch die Röntgenuntersuchung vor. Da jeder Anwender ionisierender Strahlen verpflichtet ist, jede unnötige Strahlenexposition von Mensch und Umwelt zu vermeiden, müssen bestehende Defizite in Bezug auf die Anwendung der Projektionsradio-grafie abgebaut werden und die Vermittlung von Wissen und praktischen Fertigkeiten auf diesem Gebiet während der tierärztlichen Ausbildung verbessert werden. Ebenso sollte eine Feh-lerbeseitigung durch Ausnutzung oder Verbesserung der technischen Möglichkeiten erfolgen. Eine erneute Untersuchung zur Qualität von Röntgenaufnahmen in der tierärztlichen Praxis auf der Grundlage dieser Studie erscheint zur Überprüfung der getroffenen Maßnahmen zur Ver-besserung der Bildqualität sinnvoll.:ABKÜRZUNGSVERZEICHNIS IV 1 EINLEITUNG 1 2 LITERATURÜBERSICHT 4 2.1 Strahlenschutz 4 2.1.1 Strahlenbiologische Grundlagen 4 2.1.2 Rechtliche Grundlagen 5 2.1.2.1 Anwendung von Röntgenstrahlen 5 2.1.2.2 Indikationsstellung 6 2.1.3 Technischer und praktischer Strahlenschutz 6 2.2 Bildqualität 8 2.2.1 Ermittlung der Kenngrößen eines Röntgenbildes 8 2.2.1.1 Optische Dichte 9 2.2.1.1.1 Definition der optischen Dichte 9 2.2.1.1.2 Ermittlung der optischen Dichte 10 2.2.1.2 Unschärfe 10 2.2.1.2.1 Definition der Unschärfe 10 2.2.1.2.2 Ermittlung der Unschärfe 12 2.2.1.3 Kontrast 12 2.2.1.3.1 Definition des Kontrastes 12 2.2.1.3.2 Ermittlung des Kontrastes 15 2.2.1.4 Bildrauschen 15 2.2.1.4.1 Definition des Bildrauschens 15 2.2.1.4.2 Ermittlung des Bildrauschens 16 2.2.2 Einflussfaktoren auf die Bildqualität 17 2.2.2.1 Allgemeine Fehlerquellen 17 2.2.2.2 Einfluss von Spannung und Stromstärke 17 2.2.2.3 Einfluss der Streustrahlung 18 2.2.2.4 Rastereinsatz 20 2.2.2.5 Einfluss des Objektes 21 2.2.2.6 Einfluss der Geometrie 22 2.2.2.7 Einfluss von Film und Folie 22 2.2.2.7.1 Röntgenfilm 23 2.2.2.7.2 Verstärkerfolie 24 2.2.2.8 Einfluss der Filmverarbeitung 25 2.2.2.9 Dunkelkammerarbeit 26 2.2.2.10 Artefakte 26 3 TIERE, MATERIAL UND METHODEN 28 3.1 Tiere und Material 28 3.2 Methoden 28 3.2.1 Datenerfassung und Archivierung 28 3.2.2 Befundbogen 28 3.2.2.1 Epidemiologische Daten 29 3.2.2.2 Strukturqualität 29 3.2.2.2.1 Technische Untersuchungsqualität 29 3.2.2.2.2 Technische Bildqualität 30 3.2.2.3 Prozessqualität 31 3.2.2.4 Ergebnisqualität 31 3.2.2.5 Zusammenfassende Beurteilung der Bildqualität 37 3.2.3 Datenauswertung 38 4 ERGEBNISSE 39 4.1 Epidemiologische Daten 39 4.2 Strukturqualität 42 4.2.1 Häufigkeitsanalyse 42 4.2.1.1 Zusammenfassende Beurteilung der Bildqualität 42 4.2.1.2 Technische Untersuchungsqualität 44 4.2.1.2.1 Vollständigkeit der Untersuchung 44 4.2.1.2.2 Art der Entwicklung 44 4.2.1.2.3 Streustrahlenrastereinsatz 45 4.2.1.2.4 Praktischer Strahlenschutz 46 4.2.1.2.5 Vollständige Abbildung der Region 46 4.2.1.2.6 Identifikation der Aufnahme 46 4.2.1.2.7 Kontrastmitteleinsatz 47 4.2.1.3 Technische Bildqualität 48 4.2.1.3.1 Artefakte 48 4.2.1.3.2 Lagerung und Projektion 49 4.2.1.3.3 Bildkontrast 52 4.2.1.3.4 Bildschärfe 54 4.2.2 Fehleranalyse 57 4.2.2.1 Artefakte vs. Art der Entwicklung 57 4.2.2.2 Lagerung und Projektion vs. Projektionsebene 57 4.2.2.3 Lagerung und Projektion vs. Körperregion und Projektionsebene 58 4.2.2.4 Bildschärfe vs. Körperregion und Projektionsebene 59 4.2.2.5 Bildschärfe vs. Rastereinsatz 60 4.2.2.6 Bildkontrast vs. Projektionsebene 62 4.2.2.7 Bildkontrast vs. Rastereinsatz 62 4.2.2.8 Bildkontrast vs. Art der Entwicklung 63 4.3 Strukturqualität – Konstanzanalyse der Tierarztpraxen 63 4.4 Prozessqualität 67 4.5 Ergebnisqualität 67 5 DISKUSSION 69 5.1 Methode der Beurteilung der Bildqualität 69 5.2 Zusammenfassende Beurteilung der Bildqualität 69 5.3 Vollständigkeit der Untersuchung 70 5.4 Art der Entwicklung 71 5.5 Rastereinsatz 72 5.6 Praktischer Strahlenschutz 73 5.7 Artefakte 75 5.8 Lagerung und Projektion 77 5.9 Bildschärfe 78 5.10 Bildkontrast 80 5.11 Kontrastmitteleinsatz 83 5.12 Konstanz innerhalb der Tierarztpraxen 84 5.13 Prozessqualität 85 5.14 Ergebnisqualität 86 5.15 Zusammenfassung der Diskussion und Schlussfolgerung 87 6 ZUSAMMENFASSUNG 90 7 SUMMARY 92 8 LITERATURVERZEICHNIS 94 / The aim of this study is to evaluate aspects of structural quality (technical examination and im-age quality), quality of the process (adequacy of indication) and the outcome (correctness of findings) of radiographs from the veterinary practice and to indentify frequent radiographic er-rors. For this purpose all radiographs of small animals that are received at the Department of Small Animal Medicine of the University of Leipzig between December 1st 2003 and December 31th 2004 as an original are examined for relevant features of structural quality, process quality and outcome. The data collection is done subjectively based on the consensus examination of the radiographs by two independent examiners. The evaluation includes 1259 radiographs from 600 different examinations. 86.9 % of these images come from the federal states of Germany Saxony, Saxony-Anhalt and Thuringia from 216 different veterinary practices. 80.3 % of the examined animals are dogs, 18.9 % are cats. Concerning the over-all evaluation of the image quality, 48.7 % of the radiographs are without restrictions. Minor faults are detected in 29.2 % of the radiographs, 16.0 % are diagnostically compromised and 6.1 % are insufficient. Thus, 22.1 % of the examined radiographs are unsatis-factory. They show either deficits in their diagnostic suitability or are completely useless. The most important sources of errors are faults in positioning of the patient and the following projec-tion, of image contrast and sharpness. Deviations in positioning and projection, mostly caused by a suboptimal angle in the position of the patient in the x-ray, are with 11.4 % of all radiographs in comparison to other errors relatively rare. However the effect on the diagnostic use is severe: 69.9 % of the images with positioning faults show deficits with regard to the diagnostic suitability. Regarding the contrast of the image, 33.3 % of all radiographs display deficits. The most com-mon cause is the use of exhausted developer, followed by under- and overexposure. Consider-ing the overall deviations of image contrast, 47.7 % are attributed to errors during the x-ray film development. Consequences for the diagnostic use are less serious compared to errors in posi-tioning and projection: 35.1 % of the images with contrast deviations are of limited diagnostic use. 23.0 % of the radiographs are characterized by deviations in the sharpness: motion haziness occurs most frequently (in 67.7 %) of the images concerned. Receptor unsharpness and scat-tered radiation are often observed, caused by improper use of radiographic grids and film-screen combinations. The effects on the diagnostic suitability show that 29.6 % of the radiographs with deviations in the sharpness are of limited diagnostic use. Artifacts, most frequently caused by scratches, tears and breaks of the film or the intensifying screen as well as by splashes of the developing resp. fixation reagent or water, are found on 20.7 % of all radiographs. As a result of artifacts 1.2 % of the radiographs examined show defi-cits in their diagnostic suitability. To evaluate the quality of the process the adequacy of indication is determined, which is required for every radiographic examination according to RöV § 2a (ANON. 2003a). An absolute indication can be found in 94.7 % of all images. The quality of the outcome can be discussed in almost halve of all radiographs. The referral diagnosis is medically plausible in 85.5 % of these cases. The results of this study reveal that a considerable portion of the occurring errors in the image quality are caused by a lack of care during taking and processing of the radiographic images. Deficits in the interpretation of the gained information from the radiographic examination occur as well. Since avoidance of unnecessary exposure of humans and the environment to radiation is a major obligation of every user of ionizing radiation, existing deficits regarding the use of projection radiography should be reduced and the transfer of knowledge and practical capabili-ties in this area during the veterinary training should be improved. Furthermore, the elimination of errors by use or improvement of the technical possibilities is important. A new evaluation of the quality of radiographic images from the veterinary practice on the basis of this study seems useful to examine the effects of the steps taken to improve the image quality.:ABKÜRZUNGSVERZEICHNIS IV 1 EINLEITUNG 1 2 LITERATURÜBERSICHT 4 2.1 Strahlenschutz 4 2.1.1 Strahlenbiologische Grundlagen 4 2.1.2 Rechtliche Grundlagen 5 2.1.2.1 Anwendung von Röntgenstrahlen 5 2.1.2.2 Indikationsstellung 6 2.1.3 Technischer und praktischer Strahlenschutz 6 2.2 Bildqualität 8 2.2.1 Ermittlung der Kenngrößen eines Röntgenbildes 8 2.2.1.1 Optische Dichte 9 2.2.1.1.1 Definition der optischen Dichte 9 2.2.1.1.2 Ermittlung der optischen Dichte 10 2.2.1.2 Unschärfe 10 2.2.1.2.1 Definition der Unschärfe 10 2.2.1.2.2 Ermittlung der Unschärfe 12 2.2.1.3 Kontrast 12 2.2.1.3.1 Definition des Kontrastes 12 2.2.1.3.2 Ermittlung des Kontrastes 15 2.2.1.4 Bildrauschen 15 2.2.1.4.1 Definition des Bildrauschens 15 2.2.1.4.2 Ermittlung des Bildrauschens 16 2.2.2 Einflussfaktoren auf die Bildqualität 17 2.2.2.1 Allgemeine Fehlerquellen 17 2.2.2.2 Einfluss von Spannung und Stromstärke 17 2.2.2.3 Einfluss der Streustrahlung 18 2.2.2.4 Rastereinsatz 20 2.2.2.5 Einfluss des Objektes 21 2.2.2.6 Einfluss der Geometrie 22 2.2.2.7 Einfluss von Film und Folie 22 2.2.2.7.1 Röntgenfilm 23 2.2.2.7.2 Verstärkerfolie 24 2.2.2.8 Einfluss der Filmverarbeitung 25 2.2.2.9 Dunkelkammerarbeit 26 2.2.2.10 Artefakte 26 3 TIERE, MATERIAL UND METHODEN 28 3.1 Tiere und Material 28 3.2 Methoden 28 3.2.1 Datenerfassung und Archivierung 28 3.2.2 Befundbogen 28 3.2.2.1 Epidemiologische Daten 29 3.2.2.2 Strukturqualität 29 3.2.2.2.1 Technische Untersuchungsqualität 29 3.2.2.2.2 Technische Bildqualität 30 3.2.2.3 Prozessqualität 31 3.2.2.4 Ergebnisqualität 31 3.2.2.5 Zusammenfassende Beurteilung der Bildqualität 37 3.2.3 Datenauswertung 38 4 ERGEBNISSE 39 4.1 Epidemiologische Daten 39 4.2 Strukturqualität 42 4.2.1 Häufigkeitsanalyse 42 4.2.1.1 Zusammenfassende Beurteilung der Bildqualität 42 4.2.1.2 Technische Untersuchungsqualität 44 4.2.1.2.1 Vollständigkeit der Untersuchung 44 4.2.1.2.2 Art der Entwicklung 44 4.2.1.2.3 Streustrahlenrastereinsatz 45 4.2.1.2.4 Praktischer Strahlenschutz 46 4.2.1.2.5 Vollständige Abbildung der Region 46 4.2.1.2.6 Identifikation der Aufnahme 46 4.2.1.2.7 Kontrastmitteleinsatz 47 4.2.1.3 Technische Bildqualität 48 4.2.1.3.1 Artefakte 48 4.2.1.3.2 Lagerung und Projektion 49 4.2.1.3.3 Bildkontrast 52 4.2.1.3.4 Bildschärfe 54 4.2.2 Fehleranalyse 57 4.2.2.1 Artefakte vs. Art der Entwicklung 57 4.2.2.2 Lagerung und Projektion vs. Projektionsebene 57 4.2.2.3 Lagerung und Projektion vs. Körperregion und Projektionsebene 58 4.2.2.4 Bildschärfe vs. Körperregion und Projektionsebene 59 4.2.2.5 Bildschärfe vs. Rastereinsatz 60 4.2.2.6 Bildkontrast vs. Projektionsebene 62 4.2.2.7 Bildkontrast vs. Rastereinsatz 62 4.2.2.8 Bildkontrast vs. Art der Entwicklung 63 4.3 Strukturqualität – Konstanzanalyse der Tierarztpraxen 63 4.4 Prozessqualität 67 4.5 Ergebnisqualität 67 5 DISKUSSION 69 5.1 Methode der Beurteilung der Bildqualität 69 5.2 Zusammenfassende Beurteilung der Bildqualität 69 5.3 Vollständigkeit der Untersuchung 70 5.4 Art der Entwicklung 71 5.5 Rastereinsatz 72 5.6 Praktischer Strahlenschutz 73 5.7 Artefakte 75 5.8 Lagerung und Projektion 77 5.9 Bildschärfe 78 5.10 Bildkontrast 80 5.11 Kontrastmitteleinsatz 83 5.12 Konstanz innerhalb der Tierarztpraxen 84 5.13 Prozessqualität 85 5.14 Ergebnisqualität 86 5.15 Zusammenfassung der Diskussion und Schlussfolgerung 87 6 ZUSAMMENFASSUNG 90 7 SUMMARY 92 8 LITERATURVERZEICHNIS 94

In augmented reality, information is often distributed between real and virtual contexts, and often appears at different distances from the viewer. This raises the issues of (1) context switching, when attention is switched between real and virtual contexts, (2) focal distance switching, when the eye accommodates to see information in sharp focus at a new distance, and (3) transient focal blur, when information is seen out of focus, during the time interval of focal distance switching. This dissertation research has quantified the impact of context switching, focal distance switching, and transient focal blur on human performance and eye fatigue in both monocular and binocular viewing conditions. Further, this research has developed a novel font that when seen out-of-focus looks sharper than standard fonts. This SharpView font promises to mitigate the effect of transient focal blur. Developing this font has required (1) mathematically modeling out-of-focus blur with Zernike polynomials, which model focal deficiencies of human vision, (2) developing a focus correction algorithm based on total variation optimization, which corrects out-of-focus blur, and (3) developing a novel algorithm for measuring font sharpness. Finally, this research has validated these fonts through simulation and optical camera-based measurement. This validation has shown that, when seen out of focus, SharpView fonts are as much as 40 to 50% sharper than standard fonts. This promises to improve font legibility in many applications of augmented reality.

Automatic video quality assessment has many potential use cases in today’s video-filledsociety, for example, when trying to find highlights in a video. This thesis studies the possibilityof extracting the best segments from a video automatically based on five selected metrics:sharpness, colorfulness, contrast, stability, and aesthetics. Multiple different methods from eachmetric category were compared against each other using datasets with subjective ratings ofimages from KADID-10k and videos from LIVE-Qualcomm. The best method from eachcategory was combined into a single video quality score. The combination was done through aweighted sum, obtained from a least-square fit on the subjective scores of a training dataset(KonViD-1k). The segment of a video with the highest average quality score was chosen as thehighlight. The video quality score achieved Spearman correlations of 0.67 and 0.7 whenevaluated on two validation datasets (KonViD-150k-B and LIVE-VQC). In conclusion, themetrics work well, but are currently too slow for the intended target platform (mobile devices)and thus future work should focus on improving their performance.

Indiana University-Purdue University Indianapolis (IUPUI) / Convolutional Neural Networks have come a long way since AlexNet. Each year the limits of the state of the art are being pushed to new levels. EfficientNet pushed the performance metrics to a new high and EfficientNetV2 even more so. Even so, architectures for mobile applications can benefit from improved accuracy and reduced model footprint. The classic Inverted Residual block has been the foundation upon which most mobile networks seek to improve. EfficientNet architecture is built using the same Inverted Residual block. In this thesis we experiment with Harmonious Bottlenecks in place of the Inverted Residuals to observe a reduction in the number of parameters and improvement in accuracy. The designed network is then deployed on the NXP i.MX 8M Mini board for Image classification. / 2023-10-11