Digital Stack Photography and Its Applications

<p>This work centers on digital stack photography and its applications.</p><p>A stack of images refer, in a broader sense, to an ensemble of</p><p>associated images taken with variation in one or more than one various </p><p>values in one or more parameters in system configuration or setting.</p><p>An image stack captures and contains potentially more information than</p><p>any of the constituent images. Digital stack photography (DST)</p><p>techniques explore the rich information to render a synthesized image</p><p>that oversteps the limitation in a digital camera's capabilities.</p><p>This work considers in particular two basic DST problems, which had</p><p>been challenging, and their applications. One is high-dynamic-range</p><p>(HDR) imaging of non-stationary dynamic scenes, in which the stacked</p><p>images vary in exposure conditions. The other</p><p>is large scale panorama composition from multiple images. In this</p><p>case, the image components are related to each other by the spatial</p><p>relation among the subdomains of the same scene they covered and</p><p>captured jointly. We consider the non-conventional, practical and</p><p>challenge situations where the spatial overlap among the sub-images is</p><p>sparse (S), irregular in geometry and imprecise from the designed</p><p>geometry (I), and the captured data over the overlap zones are noisy</p><p>(N) or lack of features. We refer to these conditions simply as the</p><p>S.I.N. conditions.</p><p>There are common challenging issues with both problems. For example,</p><p>both faced the dominant problem with image alignment for</p><p>seamless and artifact-free image composition. Our solutions to the</p><p>common problems are manifested differently in each of the particular</p><p>problems, as a result of adaption to the specific properties in each</p><p>type of image ensembles. For the exposure stack, existing</p><p>alignment approaches struggled to overcome three main challenges:</p><p>inconsistency in brightness, large displacement in dynamic scene and</p><p>pixel saturation. We exploit solutions in the following three</p><p>aspects. In the first, we introduce a model that addresses and admits</p><p>changes in both geometric configurations and optical conditions, while</p><p>following the traditional optical flow description. Previous models</p><p>treated these two types of changes one or the other, namely, with</p><p>mutual exclusions. Next, we extend the pixel-based optical flow model</p><p>to a patch-based model. There are two-fold advantages. A patch has</p><p>texture and local content that individual pixels fail to present. It</p><p>also renders opportunities for faster processing, such as via</p><p>two-scale or multiple-scale processing. The extended model is then</p><p>solved efficiently with an EM-like algorithm, which is reliable in the</p><p>presence of large displacement. Thirdly, we present a generative</p><p>model for reducing or eliminating typical artifacts as a side effect</p><p>of an inadequate alignment for clipped pixels. A patch-based texture</p><p>synthesis is combined with the patch-based alignment to achieve an</p><p>artifact free result.</p><p>For large-scale panorama composition under the S.I.N. conditions, we</p><p>have developed an effective solution scheme that significantly reduces</p><p>both processing time and artifacts. Previously existing approaches can</p><p>be roughly categorized as either geometry-based composition or feature</p><p>based composition. In the former approach, one relies on precise</p><p>knowledge of the system geometry, by design and/or calibration. It</p><p>works well with a far-away scene, in which case there is only limited</p><p>variation in projective geometry among the sub-images. However, the</p><p>system geometry is not invariant to physical conditions such as</p><p>thermal variation, stress variation and etc.. The composition with</p><p>this approach is typically done in the spatial space. The other</p><p>approach is more robust to geometric and optical conditions. It works</p><p>surprisingly well with feature-rich and stationary scenes, not well</p><p>with the absence of recognizable features. The composition based on</p><p>feature matching is typically done in the spatial gradient domain. In</p><p>short, both approaches are challenged by the S.I.N. conditions. With</p><p>certain snapshot data sets obtained and contributed by Brady et al, </p><p>these methods either fail in composition or render images with</p><p>visually disturbing artifacts. To overcome the S.I.N. conditions, we</p><p>have reconciled these two approaches and made successful and</p><p>complementary use of both priori and approximate information about</p><p>geometric system configuration and the feature information from the</p><p>image data. We also designed and developed a software architecture</p><p>with careful extraction of primitive function modules that can be</p><p>efficiently implemented and executed in parallel. In addition to a</p><p>much faster processing speed, the resulting images are clear and</p><p>sharper at the overlapping zones, without typical ghosting artifacts.</p>Dissertatio

Through the threaded needle : A multi-sited ethnography on the sociomateriality of garment mending practices

Commonly associated with times of hardship and austerity, garment mending has come a long way from being a domesticated practice of need to an act of commodity activism. As a backlash to the ‘throw away’ culture of fast fashion, recent years have witnessed the emergence of various public garment mending events in Western countries. Although academic interest in mending has been growing among fashion researchers, their focus has remained limited to an exploration of perspectives on mending in domestic spaces. Through this dissertation a shift is made towards an examination of processes undertaken to mend by studying existing off-the-grid mending practices that run parallel to mainstream fast-fashion systems in self-organized communal repair events in four cities. How the practice of mending comes to matter is comprehensively investigated through this dissertation. This study primarily intends to understand, observe and illustrate an alternative conceptualization, by proposing to examine mending as a sociomaterial practice. Through identifying humans and non-human or social and material forces as intimately interlaced, this study anchors itself in a pragmatic philosophical paradigm. Building on this, scholarly works that forms part of the umbrella term ‘Practice Theories’ are used to develop a non-cognitive driven understanding of the practice of mending in a clothing use context. The work draws on three years of in-depth, multi-sited ethnographic field research in 18 communal garment mending events in: Helsinki (Finland), Auckland and Wellington (New Zealand) and Edinburgh (the United Kingdom), during 2016–2018. Data is gathered through non-participant and participant observations, 67 in-depth semi- and unstructured interviews of event organizers and participants, short surveys, web research, and pictures and short video clips are used as mnemonic support. First, I strived to understand the practice of mending by identifying the matters of mending (Article 1). Then I used three effects arising from the produced affectivity of sociomaterial practices to explore mending. These conceptual effects were: creativity, learning and taste. Each effect then provided a framework through which to approach, analyse and understand the performance, learning and sustenance of mending practices. In the first instance, I categorized users as vernacular menders and understood their practices as situated, embodied and routinized, yet dynamic. The analysis revealed how when performing practices, menders methodically organized their practices while simultaneously creatively extending design in use (Article 2). In the second instance, I understood the learning practices of the vernacular menders as being anchored within the sociomateriality of practices rather than resulting from a purely cognitive process. The learned outcomes were: material learning, communal learning and environmental learning. Through the process of mending, the vernacular menders seemed to learn how to identify variations in material qualities, create communal bonds and form understandings of how to better care for their garments. The findings indicated the potential of informal learning platforms for finding sustainable local solutions to global ecological problems concerning garment waste (Article 3). In the last instance, the focus was on the role of the body and the interplay between the sensing body and the materials, to show how menders construct taste for and form an attachment to their practice over time. Their mending practices resulted in increasing the physical life, reshaping the symbolic life and redefining the aesthetic life of garments. In this way, people are seen as disrupting existing social and material orders by defying mainstream fashion practices, levelling off the playing field through active engagement in appropriating garments, mobilizing variations in dress practices, attuning to the matters that make up their clothing, while also forming an attachment to their practice (Article 4). Overall, in taking a non-cognitive approach to the study of mending, this study reveals the practices of menders as not merely reproductive but as dynamic and reflexive. In trying to understand how mending practices are performed, learned and sustained, the study also highlights the broader implications of mending that need attention in the current sustainable fashion discourse. Thus, the study invites future research to explore the practices of vernacular menders and to actively challenge fast fashion dictates towards the practices of caring, inclusivity and stewardship

Oceanus.

v. 26, no. 1 (1983

Fabric and Microstructural Analysis of the Loch Borralan Pluton, Northwest Highlands, Scotland

The Loch Borralan pluton was emplaced within the Assynt Region of the Moine Thrust zone during the Scandian event (ca. 435-425 Ma) of the Caledonian Orogeny (478-425 Ma). It consists of two major magma suites, the syenitic early suite (431.1 ± 1.2 Ma), and the quartz syenitic later suite (429.2 ± 0.5 Ma). The region is characterized by a series of in-sequence thrust faults that strike NE-SW and dip approximately 20± to the SE, including (from lower to upper): the Sole Thrust, the Borralan Thrust (hypothesized, but not exposed), the Ben More Thrust, and the Moine Thrust. A series of imbricate thrusts between the Sole and Borralan Thrusts juxtapose repeated Cambrian and Ordovician strata. The Loch Borralan pluton intruded between the Sole and Ben More thrust faults, and may be bounded below by a hypothesized Borralan Thrust fault. Based on the overlap in pluton crystallization age and orogenic activity, the combination of macroscopic field lineation and foliation measurements, anisotropy of magnetic susceptibility (AMS) lineation and foliations measurements, mineral shape preferred orientation (SPO) analysis, and petrographic deformation microstructure analysis will be used to determine if the pluton expresses deformation features and fabrics corresponding to thrust fault tectonics. The dominant magnetic mineralogy as determined by thermomagnetic data and hysteresis plots was determined to be magnetite and titanomagnetite. Some paramagnetic components were seen in the early suite, and can be attributed to biotite. Both minerals contributed to the AMS signal that was used to interpret pluton fabrics. The pluton contains S\u3eL (foliation stronger than lineation) fabrics throughout, defined by alignment of alkali feldspar grains. The foliation strike of both the early and late suites are subparallel to the thrust faults, providing evidence that the fabrics are related to deformation. The early suite is only well exposed in the southeast at the top of the Borralan thrust sheet, and proximal to the bottom of the Ben More Thrust fault. Foliations strike approximately 030 and dip 20° SE. Mineral lineations were not readily seen in the early suite. AMS results show mean principal susceptibilities (K1\u3eK2\u3eK3) parallel to field measurements. Mineral foliations in the late suite have a similar strike to early suite foliations, but dip roughly 50-60± both to the NW and SE. AMS foliations parallel mineral foliations, and strike generally NE-SW. AMS foliation dips are more variable, spanning the range of possible dip angles. The variance in foliation dips are likely caused by a composite magnetic fabric resulting from thrusting combined with thrust parallel flattening. Lineations in the late suite are scarce, but generally plunge shallowly to the NE and SW indicating horizontal extrusion parallel to the strike of the thrust faults. Similarly, most late suite AMS lineations plunge shallowly perpendicular to thrust transport direction corroborating the field measurements. Some late suite AMS lineations plunge parallel to thrust transport direction, suggesting there are also components of simple shear related to thrusting, with partitioning varying throughout the late suite. The foliation dip degree variation between the two suites could be the result of the spatial relationships and/or timing. The pluton is interpreted to have been emplaced syn-kinematically, deformed via thrusting related simple shear in the early suite, and with a component of flattening and lateral extrusion added in the late suite. Shape preferred orientation (SPO) measurements were conducted using the intercept method of image analysis to relate mineral fabrics to AMS measurements. SPO are generally weak, and have low shape ratio values. Mineral orientation parallels magnetic mineral fabric within each thin section, which supports AMS measurements as representative of mineral fabric. Petrographic microstructural thin section analysis was performed to analyze deformation mechanisms to deformation conditions. Feldspars exhibited both crystal plastic (ductile) and brittle microstructures. Examples of crystal plastic microstructures seen in feldspars include: perthite and myrmekite, undulose extinction, grain boundary bulging. Feldspars also showed quartz filled fractures (brittle deformation), which occasionally formed conjugate sets relative to AMS principal susceptibilities. Quartz was primarily seen only in the northwest extent of the pluton. Quartz also had both crystal plastic and brittle microstructures. Crystal plastic microstructures seen in quartz include: dynamic recrystallization, undulose extinction (recrystallized and primary grains), and grain boundary bulging. Examples of brittle microstructures in quartz are intragranular fractures. Deformation temperature conditions range from high grade to low grade. The presence of structures such as perthite and myrmekite textures infer deformation temperatures of around 600±C, and on the low end brittle deformation in either quartz or feldspars suggest sub 300±C. The range of deformation temperatures suggest that the pluton was emplaced synkinematically and deformation continued throughout its cooling history. The strong agreement between field and AMS measurements combined with evidence for high temperature deformation conditions suggests the pluton intruded syn-tectonically. The majority of deformation is seen in the early suite, and southeastern late suite. These locations are closest to the Ben More thrust, suggesting that movement along this thrust caused the majority of deformation. Based on AMS orientations, deformation in the early suite is accommodated as thrust motion related simple shear. Late suite deformation has a combination of thrusting simple shear, general flattening, and lateral extrusion. Since the pluton was likely roofed by thrust faults restricting upward flow, space for the magma was created through lateral extrusion

Considerations on Acoustic Mapping Velocimetry (AMV) Application for in-situ Measurement of Bedform Dynamics

Non-intrusive technologies for the in-situ measurement of river morphological features are increasingly popular in the scientific and practice communities due to their efficient and productive data acquisition. While the measurement of suspended load with optical and acoustic technologies is currently an active area of research, the measurement of bedform dynamics has not experienced similar progress. We have successfully demonstrated through laboratory experiments that, by combining acoustic mapping with image velocimetry concepts, we can characterize the planar dynamics of the bedform migration. The technique, labeled Acoustic Mapping Velocimetry (AMV), is currently transferred to field conditions using multiple-beam echo-sounders (MBES) for producing acoustic maps. During this transfer, new questions emerged because, in field conditions, many of the morphologic features targeted by AMV measurements are not a priori known. Moreover, the image velocimetry processing can be approached with several alternatives, each of them characterized by strength and limitations. This paper assembles guidelines for establishing optimal parameters for the acquisition of the acoustic maps based on analytical considerations, and for selecting essential features of the processing for image velocimetry. We test these guidelines using MBES data acquired in the Mississippi River

ICS Materials. Towards a re-Interpretation of material qualities through interactive, connected, and smart materials.

The domain of materials for design is changing under the influence of an increased technological advancement, miniaturization and democratization. Materials are becoming connected, augmented, computational, interactive, active, responsive, and dynamic. These are ICS Materials, an acronym that stands for Interactive, Connected and Smart. While labs around the world are experimenting with these new materials, there is the need to reflect on their potentials and impact on design. This paper is a first step in this direction: to interpret and describe the qualities of ICS materials, considering their experiential pattern, their expressive sensorial dimension, and their aesthetic of interaction. Through case studies, we analyse and classify these emerging ICS Materials and identified common characteristics, and challenges, e.g. the ability to change over time or their programmability by the designers and users. On that basis, we argue there is the need to reframe and redesign existing models to describe ICS materials, making their qualities emerge