Civil War images are important visual records that captured and depict the realities endured by the American people during the Civil War. These images are a powerful visual platform that depicts the vivid representation of past history. Images of Civil War are frequently used as interpretive media, particularly at historic battlefields to enhance the visitor experience and understanding. However, empirical studies of the characteristics of Civil War images that can influence visitors\' experience are limited. Using historic images of Civil War landscapes, this study identified visitors\' preferences and attitudes for Civil War images at five different American Civil War battlefields: Chickamauga and Chattanooga Chickamauga and Chattanooga National Military Park, Shiloh National Military Park, Manassas National Battlefield Park, Antietam National Battlefield, and Gettysburg National Military Park. For this study, the Content Identifying Method (CIM) and eye-tracking technology were used in understanding visitors\' preferences. The results indicate that visitors at historic battlefields prefer images that have a strong sense of active military activities and battle-related action. In addition visitors also preferred images that exhibit a high sense of mystery and are visually complex. The study also revealed that visitor background variables such as gender, age group, and ancestors who fought in the Civil War significantly influence visitor preference for Civil War images. Motivation variables such as interest in learning about "the people," "the military elements," "physical artifacts of the Civil War," and distance travelled to historic battlefields also significantly influence visitor preferences. In term of visitor attitudes towards gruesome images, the majority of the participants believe that these types of images are important visual media that can influence their visitation experience at historic battlefields. Eye-tracking technology was useful in revealing the content that attracted participant attention in some of the images, but not in other images. This study provides information that will be useful to park managers and interpretive designers regarding the characteristics of Civil War images that are important in developing interpretive media for the public and factors that may help in the process of customizing the visitor experience at historic battlefields. / Ph. D.

Hardwood timber is a substantial economic staple in the eastern U.S., where primary hardwood processors produce more than 10 billion board feet of sawn hardwoods annually. There are over 3,500 sawmills producing hardwood lumber in the Southeastern portion of the United States. Present trends such as increasing labor costs and limited supplies of high quality logs have forced hardwood lumber manufacturers to increase their efforts to maximize the utilization of this raw material. In order to make money in such a competitive business, these sawmills must produce the highest possible grade of lumber from each saw log they process. Of all the primary and secondary processing procedures that are used to transform round wood into a final product, the sawmill edging and trimming operations have the most substantial effect on the grade and, hence, the value of the material produced. Currently, the grading of rough hardwood lumber is done manually by human inspectors according to standardized grading rules developed by the National Hardwood Lumber Association (NHLA, 1994). Standard hardwood edging and trimming operations are less than optimum because of the complexity of the grading rules, the complexity of the decision making processes involved, possible operator fatigue, and the imprecision with which lumber can be sawn by the available equipment. Studies have shown that there is a potential to increase hardwood lumber value by over 20 percent if optimum edging and trimming could be performed in hardwood sawmills. Even a small portion of this percentage would substantially increase the profit of hardwood lumber manufacturers. And this can be achieved just by utilizing some degree of automation. That is, some type of system must be designed that can scan a board to sense important hardwood features, make correct edging and trimming decisions, and then control down stream edgers and trimmers with minimal operator intervention. The most difficult part in the development of this automatic edging and trimming system is to get enough major defect information to make very good edging and trimming decisions. This thesis describes the research that was performed to build a prototype system that can collect images of boards and extract major defect information for making good edging and trimming decisions. The images that are collected include Black/White and laser profile images. Necessary defect information to be extracted for making edging and trimming decisions includes the location and size of large grading defects and areas of the board that are too thin. This thesis talks about the hardware that was used for collecting the needed board images. This includes a discussion of both the Black/White and laser profile imaging systems. The data collection boards that were used for transferring images from these imaging systems to computer memory are also described. This thesis also describes the computer vision algorithms that were developed to extract defect information needed for making improved edging and trimming decisions. Some of the processing steps involved include background extraction, both global and local segmentation, connected component labeling and small area elimination and merging. Processing results obtained of green red oak samples show that both hardware and software of the prototype system seem to work well. However, since the program needed to actually create the edging and trimming solution based on defect information found by the computer vision system was not available it was impossible to quantitatively determine the value improvement to proposed system might offer. / Master of Science

Yes / Edge detection plays an important role in human vision, and although it is clear that there are luminance edge detectors, it is not known whether there are chromatic edge detectors as well.We showed observers a horizontal edge blurred by a Gaussian filter (with widths of r ¼ 0.1125, 0.225, or 0.458) embedded in blurred Brown noise. Observers had to choose which of two stimuli contained the edge. Brown noise was used in preference to white noise to reveal localized edge detectors. Edges and noise were defined by either luminance or chromatic contrast (isoluminant L/M and S-cone opponent). Classification image analysis was applied to observer responses. In this analysis, the random components of the stimulus are correlated with observer responses to reveal a template that shows how observers weighted different parts of the stimulus to arrive at their decision.We found classification images for both luminance and isoluminant chromatic stimuli that had shapes very similar to derivatives of Gaussian filters. The widths of these classification images tracked the widths of the edges, but the chromatic edge classification images were wider than the luminance ones. These results are consistent with edge detection filters sensitive to luminance contrast and isoluminant chromatic contrast. / Royal Society Travel Grant IE130877 and in part by Canadian Institutes of Health Research (CIHR) grant MOP-10819

Yes / Edge detection is widely believed to be an important early stage in human visual processing. However, there have been relatively few attempts to map human edge detection filters. In this study, observers had to locate a randomly placed step edge in brown noise (the integral of white noise) with a 1/𝑓2 power spectrum. Their responses were modelled by assuming the probability the observer chose an edge location depended on the response of their own edge detection filter to that location. The observer’s edge detection filter was then estimated by maximum likelihood methods. The filters obtained were odd-symmetric and similar to a derivative of Gaussian, with a peak-to-trough width of 0.1–0.15 degrees. These filters are compared with previous estimates of edge detectors in humans, and with neurophysiological receptive fields and theoretical edge detectors.

Yes / In this paper, a new approach to modelling 3D faces based on 2D images is introduced. Here 3D faces are created using two photographs from which we extract facial features based on image manipulation techniques. Through the image manipulation techniques we extract the crucial feature lines of the face in two views. These are then used in modifying a template base mesh which is created in 3D. This base mesh, which has been designed by keeping facial animation in mind, is then subdivided to provide the level of detail required. The methodology, as it stands, is semi-automatic whereby our goal is to automate this process in order to provide an inexpensive and expedient way of producing realistic face models intended for animation purposes. Thus, we show how image manipulation techniques can be used to create binary images which can in turn be used in manipulating a base mesh that can be adapted to a given facial geometry. In order to explain our approach more clearly we discuss a series of examples where we create 3D facial geometry of individuals given the corresponding image data.

No description available.

High quality digital images have become pervasive in modern scientific and everyday life — in areas from photography to astronomy, CCTV, microscopy, and medical imaging. However there are always limits to the quality of these images due to uncertainty and imprecision in the measurement systems. Modern signal processing methods offer the promise of overcoming some of these problems by postprocessing these blurred and noisy images. In this thesis, novel methods using nonstationary statistical models are developed for the removal of blurs from out of focus and other types of degraded photographic images. The work tackles the fundamental problem blind image deconvolution (BID); its goal is to restore a sharp image from a blurred observation when the blur itself is completely unknown. This is a “doubly illposed” problem — extreme lack of information must be countered by strong prior constraints about sensible types of solution. In this work, the hierarchical Bayesian methodology is used as a robust and versatile framework to impart the required prior knowledge. The thesis is arranged in two parts. In the first part, the BID problem is reviewed, along with techniques and models for its solution. Observation models are developed, with an emphasis on photographic restoration, concluding with a discussion of how these are reduced to the common linear spatially-invariant (LSI) convolutional model. Classical methods for the solution of illposed problems are summarised to provide a foundation for the main theoretical ideas that will be used under the Bayesian framework. This is followed by an indepth review and discussion of the various prior image and blur models appearing in the literature, and then their applications to solving the problem with both Bayesian and nonBayesian techniques. The second part covers novel restoration methods, making use of the theory presented in Part I. Firstly, two new nonstationary image models are presented. The first models local variance in the image, and the second extends this with locally adaptive noncausal autoregressive (AR) texture estimation and local mean components. These models allow for recovery of image details including edges and texture, whilst preserving smooth regions. Most existing methods do not model the boundary conditions correctly for deblurring of natural photographs, and a Chapter is devoted to exploring Bayesian solutions to this topic. Due to the complexity of the models used and the problem itself, there are many challenges which must be overcome for tractable inference. Using the new models, three different inference strategies are investigated: firstly using the Bayesian maximum marginalised a posteriori (MMAP) method with deterministic optimisation; proceeding with the stochastic methods of variational Bayesian (VB) distribution approximation, and simulation of the posterior distribution using the Gibbs sampler. Of these, we find the Gibbs sampler to be the most effective way to deal with a variety of different types of unknown blurs. Along the way, details are given of the numerical strategies developed to give accurate results and to accelerate performance. Finally, the thesis demonstrates state of the art results in blind restoration of synthetic and real degraded images, such as recovering details in out of focus photographs.

This thesis examines how images are used and evaluated in a Swedish archival context. Images as of today are very common in society. They are nearly everywhere, particularly in our phones and computers. Therefore the written word is slowly losing it's sovereignty as a carrier of information. With this background the study examines if the images role also have changed in an archival setting. The following work is a qualitative research study that examines three Swedish archives: the Regional State Archive in Uppsala, Swedish Labour Movement's Archives and Library in Stockholm and the Centre for Business History in Stockholm. Furthermore the study examines how the institutions organize images and how they make them accessible for the public. It also examines what role the image play as a carrier of information in the archive. In more general terms the study also investigates what function the image can have for people in society. The comparison of the archival institutions is a methodological foundation for this study. Semi- structured interviews were conducted with archivists from the three institutions and works as the main source. For the analysis this study uses document theory and a few concepts derived from Terry Cook's archival theory, namely evidence, memory, identity and community. In terms with the previous research made on the subject this study comes to the result that images have different terms for archiving than other materials, most specifically papers documents. The examined archival institutions are today using the same tools for organizing images as they use for other documents. This can have negative effects on the ability the image has as a carrier of information. In the long run this could cause the image to become a marginalized part of the archive as a whole. The conclusion this mater's thesis presents is that the image has a potential as a source of information. Especially for groups that aren't previously represented in the archive through traditional paper documents. The image may therefore contribute to the archival pluralism and diversity, as long as the images are treated with the terms they demand as an archival document. This is a two years master's thesis in Archival Science.

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal.

Les images dans toute leur diversité, installées dans l'espace urbain composent notre objet d'étude. Ainsi, à partir de l'analyse d'un vaste corpus composé de photographies et de cartes, collectés durant un long période dans le centre-ville de Santiago, l'enjeu est de saisir l'objet image-contexte qui d'après une description cas-à-cas, nous permettra l'analyse de l'image en situation. Dont le but est l'observation du rôle des images dans la construction de l'espace urbain et en tant que composant fondamental de notre environnement quotidien. De ce fait, divers aspects apparaissent peu à peu le long du travail telles que ; la distribution des images en relation au rapport des forces des pouvoirs quelles représentent et dans l'ensemble révèlent les pratiques spatiales du groupe social, de voir comment l'image transforme l'espace et l'espace redéfinit l'image, la relation entre image et architecture, entre la dynamique des images et les dynamiques urbaines et l'irruption des nouvelles technologies dans l'espace urbain. En somme, tout au long de notre travail de recherche nous poursuivons la constitution progressive de l'image en situation en tant qu'objet de terrain et élément essentiel qui façonnera le paysage visuel des villes dans le XXIe siècle / Images, in all their diversity, present in the urban environment, form the subject of our study. Thus, with the starting point a vast cache of photographs and cards, collected over a long period in Santiago city-center, the issue involves comprehending the image/context as a whole, a task that, after a case-by-case examination, will allow us to analyze the image as an integral part of its location. The goal, therefore, is the observation of the role of images in the construction of the urban environment and as fundamental components of our everyday surroundings. In this way, various aspects come to the fore throughout the process: the distribution of images relative to the power of the forces they represent reveals, in the whole, the spatial activities of the social group; the way in which the image transforms the space and the space in turn redefines the image; the relationship between image and architecture; between the dynamics of the image and the urban dynamics; and, lastly, the impact of new technologies on the urban landscape. In summation, throughout our research we have followed the progressive existence of location-specific imagery as an object in its own right and an essential element that will shape the visual landscape of cities in the 21st century