Single Photos Research Articles

Poor Man's Line Scan – a simple tool for the acquisition of high-resolution, undistorted drill core photos

Abstract. The analysis and presentation of drill cores, an essential part of geoscientific research, requires the acquisition of high-quality core photos. Typically, core photos are either taken by hand, which often results in poor and inconsistent image quality and perspective distortions, or with large, heavy, and thus inflexible as well as expensive line scan setups. We present a simple, portable “Poor Man's Line Scan” setup that turns a customary smartphone into a semi-automatic core scanner utilising its panoramic photo function while guided on a rail in order to record undistorted core photographs at high resolution. The resulting images, although affected by some minor artefacts, are clearly superior in quality and resolution to single photos taken by hand and are comparable to images taken with commercial line scan cameras. The low cost (∼ EUR 100) and high flexibility, including the potential for modifications, of our tool make it an interesting alternative to the classical line scan setup.

Provoked overt recognition in acquired prosopagnosia using multiple different images of famous faces

ABSTRACT Provoked overt recognition refers to the fact that patients with acquired prosopagnosia can sometimes recognize faces when presented in arrays of individuals from the same category (e.g., actors or politicians). We ask whether a prosopagnosic patient might experience recognition when presented with multiple different images of the same face simultaneously. Over two sessions, patient Herschel, a 66-year-old British man with acquired prosopagnosia, viewed face images individually or in arrays. On several occasions he failed to recognize single photos of an individual but successfully identified that person when the same photos were presented together. For example, Herschel failed to recognize any individual images of King Charles or Paul McCartney but recognised both in arrays of the same photos. Like reports based on category membership, overt recognition was transient and inconsistent. These findings are discussed in terms of models of covert recognition, alongside more recent research on within-person variability for face perception.

Accuracy and Consistency in Social Categorization Across Context, Motivation, and Time

Photos provide a literal snapshot of a person in a particular context at a specific moment in time. Previous studies have found that people can accurately categorize others from single photos of their faces along various social dimensions, yet this research typically assumes that one photo of an individual representatively samples other photos of the same individual. Across four studies, we investigated this assumption by testing the consistency of perceptions of social categories (viz. sexual orientation and political affiliation) based on multiple photos of the same individuals. We found that judgments of social categories exceeded chance and significantly correlated across different photo contexts, across variability in targets’ motivations, and across time. These data supplement earlier work showing similar consistency for other types of social judgments. Thus, single face photos can consistently convey some aspects of an individual's appearance.

Monitoring Dropping Densities with Unmanned Aerial Vehicles (UAV): An Effective Tool to Assess Distribution Patterns in Field Utilization by Foraging Geese

Counting of droppings is often, with great effect, used as an indirect method to monitor the appearance and usage of an area by a population covering longer time spans. However, manual detecting and counting of droppings can be time-consuming and tedious, and with a risk of resulting in course estimations. In this context, we studied the use of imaging from unmanned aerial vehicles (UAVs) as a novel and enhanced tool to estimate the dropping densities and distributions of field foraging Arctic migratory geese, such as pink-footed goose Anser brachyrhynchus and barnacle goose Branta leucopsis. Aided by analysis in geographical information systems (GIS), we sought to detect and use fine-scale changes in the within-field dropping densities to evaluate avoidance distance to selected landscape elements. Data in the form of aerial photos from farmed grassland and pastures were collected in areas adjacent to Limfjorden, Northern Jutland, Denmark. The UAV proved usable for detecting droppings from field foraging geese, but with the applied UAV technology only at a low flying altitude (≤3 m), which rendered traditional methods for georeferencing inapplicable. A revised protocol for georeferencing of single aerial photos triggered from low altitudes was successfully developed, which was considered suitable for future use. Analyses based on the performed UAV data sampling allowed for an unprecedented fine-scale estimation of distribution patterns of the goose droppings and further for determination of optimal sampling frequencies (≤12 × 12 m spacing between photo samples) for calculation of density patterns, which reflected differences in foraging activity of geese across whole fields. Contagious dispersions in dropping densities were detected in the majority of fields indicating local, within-field displacements of the geese, which were illustrated by interpolated heatmaps. Additionally, avoidance distances were assessed for four landscape elements and detected with consistent results for windbreaks (100 m), roads (175 m) and wind turbines (1100 m) throughout the ten surveyed fields.

FUSED 3D TRANSPARENT VISUALIZATION FOR LARGE-SCALE CULTURAL HERITAGE USING DEEP LEARNING-BASED MONOCULAR RECONSTRUCTION

Abstract. This paper proposes a fused 3D transparent visualization method with the aim of achieving see-through imaging of large-scale cultural heritage by combining photogrammetry point cloud data and 3D reconstructed models. 3D reconstructed models are efficiently reconstructed from a single monocular photo using deep learning. It is demonstrated that the proposed method can be widely applied, particularly to instances of incomplete cultural heritages. In this study, the proposed method is applied to a typical example, the Borobudur temple in Indonesia. The Borobudur temple possesses the most complete collection of Buddhist reliefs. However, some parts of the Borobudur reliefs have been hidden by stone walls and became not visible following the reinforcements during the Dutch rule. Today, only gray-scale monocular photos of those hidden parts are displayed in the Borobudur Museum. In this paper, the visible parts of the temple are first digitized into point cloud data by photogrammetry scanning. For the hidden parts, a 3D reconstruction method based on deep learning is proposed to reconstruct the invisible parts into point cloud data directly from single monocular photos from the museum. The proposed 3D reconstruction method achieves 95% accuracy of the reconstructed point cloud on average. With the point cloud data of both the visible parts and the hidden parts, the proposed transparent visualization method called the stochastic point-based rendering is applied to achieve a fused 3D transparent visualization of the valuable temple.

AUTOMATIC APPLE TREE BLOSSOM ESTIMATION FROM UAV RGB IMAGERY

Abstract. Apple trees often produce high amount of fruits, which results in small, low quality fruits. Thinning in apple orchards is used to improve the quality of the apples by reducing the number of flowers or fruits the tree is producing. The current method used to estimate how much thinning is necessary is to measure flowering intensity, currently done by human visual inspection of trees in the orchard. The use of images of apple trees from ground-level to measure flowering intensity and its spatial variation through orchards has been researched with promising results. This research explores the potential of UAV RGB high-resolution imagery to measure flowering intensity. Image segmentation techniques have been used to segment the white pixels, which correspond to the apple flowers, of the orthophoto and the single photos. Single trees have been cropped from the single photos and from the orthophoto, and correlation has been measured between percentage of white pixels per tree and flowering intensity and between percentage of white pixels per tree and flower clusters. The resulting correlation is low, with a maximum of 0.54 for the correlation between white pixels per tree and flower clusters when using the ortophoto. Those results show the complexity of working with drone images, but there are still alternative approaches that have to investigated before discarding the use of UAV RGB imagery for estimation of flowering intensity.

Picture Stories: the Rise of the Photoessay in the Weimar Republic

Between the mid-1920s and the early 1930s German photojournalism experienced a profound, far-reaching upheaval. Up until this time, the illustrated mass media had favoured the reproduction of single photos, but during this brief period the photo-essay rose to prominence. Photographs and texts were integrated into a new, complex narrative unity: photoreportage. This article aims to reconstruct the historical conditions under which modern photo-reportage arose during the Weimar Republic. It will also revise certain accepted judgements about the history of photojournalism between the world wars. The development of modern photojournalism has until now been identified almost exclusively with the achievements of individual protagonists, mainly prominent photographers. Although these individuals played an important role in the production process of photoreportage, they were rarely consulted regarding editorial questions and layout. In order to better understand the economic development of photoreportage and its growth as a medium, it is necessary to examine the editorial work being done behind the scenes at the magazines and newspapers of the time. This article will therefore focus more on the development of the media and economic macrostructures at play in the emergence and growth of photo-reportage, and less on individual photographers’ contributions and photojournalistic output. It ultimately shows that the consolidation of modern photo-reportage was the result of closely connected media-related and social developments, commercial strategies and aesthetic decisions that went far beyond the agency of individuals.

Women outperform men in distinguishing between authentic and nonauthentic smiles

ABSTRACTWomen tend to be more accurate in decoding facial expressions than men. We hypothesized that women’s better performance in decoding facial expressions extends to distinguishing between authentic and nonauthentic smiles. We showed participants portrait photos of persons who smiled because either they saw a pleasant picture (authentic smile) or were instructed to smile by the experimenter (nonauthentic smile) and asked them to identify the smiles. Participants judged single photos of persons depicting either an authentic or a nonauthentic smile, and they judged adjacent photos of the same person depicting an authentic smile and a nonauthentic smile. Women outperformed men in identifying the smiles when judging the adjacent photos. We discuss implications for judging smile authenticity in real life and limitations for the observed sex difference.

Three-party Quantum Secure Direct Communication with Single Photons in both Polarization and Spatial-mode Degrees of Freedom

We present an efficient three-party quantum secure direct communication (QSDC) protocol with single photos in both polarization and spatial-mode degrees of freedom. The three legal parties’ messages can be encoded on the polarization and the spatial-mode states of single photons independently with desired unitary operations. A party can obtain the other two parties’ messages simultaneously through a quantum channel. Because no extra public information is transmitted in the classical channels, the drawback of information leakage or classical correlation does not exist in the proposed scheme. Moreover, the comprehensive security analysis shows that the presented QSDC network protocol can defend the outsider eavesdropper’s several sorts of attacks. Compared with the single photons with only one degree of freedom, our protocol based on the single photons in two degrees of freedom has higher capacity. Since the preparation and the measurement of single photon quantum states in both the polarization and the spatial-mode degrees of freedom are available with current quantum techniques, the proposed protocol is practical.

Efficient Bidirectional Quantum Secure Direct Communication with Single Photons in Both Polarization and Spatial-Mode Degrees of Freedom

With single photos in both polarization and spatial-mode degrees of freedom,we present an efficient bidirectional quantum secure direct communication (QSDC) protocol is proposed. The participants’ secret messages can be transmitted directly in a quantum channel through performing different local unitary operations, which are chosen by the two participants separately from the Pauli operations and Hadamard operations, on the polarization states and the spatial-mode states of single photons. Each single photon in two degrees of freedom can carry two bits of information. Thus the capacity of quantum communication of our protocol is improved. Moreover, we discuss the security of our QSDC network protocol comprehensively. It is showed that the proposed scheme not only can defend several outsider eavesdropper’s attacks but also can remove the drawback of information leakage, which prevents the secret messages being leaked out to other people through the public information. In addition, our protocol is practical since the preparation and the measurement of single photon quantum states in both the polarization and the spatial-mode degrees of freedom are available with current quantum techniques.

Redesigning photo-ID to improve unfamiliar face matching performance.

Viewers find it difficult to match photos of unfamiliar faces for identity. Despite this, the use of photographic ID is widespread. In this study we ask whether it is possible to improve face matching performance by replacing single photographs on ID documents with multiple photos or an average image of the bearer. In 3 experiments we compare photo-to-photo matching with photo-to-average matching (where the average is formed from multiple photos of the same person) and photo-to-array matching (where the array comprises separate photos of the same person). We consistently find an accuracy advantage for average images and photo arrays over single photos, and show that this improvement is driven by performance in match trials. In the final experiment, we find a benefit of 4-image arrays relative to average images for unfamiliar faces, but not for familiar faces. We propose that conventional photo-ID format can be improved, and discuss this finding in the context of face recognition more generally.

New records of sea anemones (Cnidaria: Anthozoa) from Costa Rica

Despite being important components in coastal marine systems, sea anemones have been poorly studied on both coasts of Costa Rica. In this paper new records of sea anemones are mentioned for the Caribbean and Pacific coasts of Costa Rica and the Isla del Coco National Park. Additionally, the presence of other species previously recorded in Costa Rica based on single observations or photos, is reconfirmed. An updated inventory of these cnidarians is provided, and with the corallimorpharians, comprises of 16 species (10 in the Caribbean and 6 in the Pacific and Coco Island). A comparison with the sea anemone fauna of Panama is added.

Automated quality assessment of retinal fundus photos

Automated, objective and fast measurement of the image quality of single retinal fundus photos to allow a stable and reliable medical evaluation. The proposed technique maps diagnosis-relevant criteria inspired by diagnosis procedures based on the advise of an eye expert to quantitative and objective features related to image quality. Independent from segmentation methods it combines global clustering with local sharpness and texture features for classification. On a test dataset of 301 retinal fundus images we evaluated our method on a given gold standard by human observers and compared it to a state of the art approach. An area under the ROC curve of 95.3% compared to 87.2% outperformed the state of the art approach. A significant p-value of 0.019 emphasizes the statistical difference of both approaches. The combination of local and global image statistics models the defined quality criteria and automatically produces reliable and objective results in determining the image quality of retinal fundus photos.

De fotografie van rampen. Objectiverende registratie of anticiperende betrokkenheid?

<strong>Photography of disasters. Objectifying registration or anticipated involvement?</strong> <strong></strong><br />The news photo has become an inextricable component of journalistic organizations. The first press photo in a Dutch newspaper was printed in 1890, but it would take another forty years for the photos to be printed togethet with their corresponding news articles. This article follows the development of press photography, specifically focussing on the documentation of large disasters such as the flood<br />disasters in 1916 and 1953, the large cinema and hotel fires in 1934 and 1977, and the fireworks disaster of Enschede in 2000. Up until the Second World War newspapers, as opposed to illustrated magazines, would only print a single photo, which was expected to provide a complete representation of the disaster. The photographer would attempt to capture a general overview of what had happened. Only later, and especially with the flood disaster in Zeeland, were the victims of the disaster photographed. The photographer finally dared to tread within the disaster zone and capture the victims in all their misery. The result of this approach were direct and emotional portraits. Changing techniques and improving communication methods allowed the photographer to document the disaster directly- as if he were involved himself. The changes triggered questions related to the recording of disasters, even more so than before: how confronting may a photograph be? Documentation of recent events, such as Enschede and Volendam, no longer suffice with single photos; newspapers instead present extensive photo reports, which preferably document the chronological sequence of events, focussing on the victims and aid. In the end it is the news editor who decides which photograph gets printed in his or her newspaper. And even though newspapers also use photographs from the larger<br />press offices, and not only from their own photographers, their personal signature is still recognisable in their choices.

An estimate of the number of G regulator proteins activated per excited rhodopsin in living Limulus ventral photoreceptors.

Previous work by others on Limulus photoreceptors has shown that application of a variety of guanine nucleotide-binding regulatory protein (G protein) activators produces discrete waves of depolarization similar to those generated by single photos, but smaller in size. We investigated whether these events might originate at a site other than the G protein. Initiation of the events did not depend on the state of the visual pigment, suggesting that the events do not originate at the pigment level. The events could be blocked by the G-protein blocker guanosine 5'-[beta-thio]diphosphate (GDP[betaS]) and thus support the conclusion that these discrete events are due to the activation of G protein itself. Quantitative measurements indicate that the average size of these events is approximately 8 times smaller than that evoked by single photons under the same conditions. Given certain reasonable assumptions, these results imply that the gain of the first stage of transduction in vivo is approximately 8, a value considerably lower than that measured in vitro in vertebrate rods (gain, 100-500). Furthermore, independent evidence for a low first-stage gain in Limulus is derived from the observation that GDP[betaS] barely affects the size of the response to single photons, but greatly reduces the probability that a photon evokes a response. These results can be explained if rhodopsin normally activates only a few G proteins.