Novel Twofold Use of Photographic Technique for Simultaneous Flow Boiling Image Recording and Void Fraction Computation in a Mini-Channel Experiment

The paper presents a novel twofold use of the photographic technique for flow boiling heat transfer investigation in the horizontal mini-channel. The dedicated measurement system was constructed to record basic thermal and flow parameters, i.e., boiling liquid inlet and outlet temperatures and pressures, and also temperatures inside the heating block to calculate heat flux going into the liquid. A high-speed video camera equipped with synchronous movement system was applied to combine the recording of two-phase flow images with simultaneous local void fraction measurements both based on the same photographic data set. The data were collected, managed, and refined with the scripts developed in the MathWorks Matlab 2019b environment. The synchronous use of two intelligent techniques in the scripts, i.e., the background subtraction technique and the statistical analysis of individual pictures allowed obtaining reliable experimental results. The proposed method of the void fraction determination ensures high measurement accuracy.

A Re-examination of Dichoptic Tone Mapping

Dichoptic tone mapping methods aim to leverage stereoscopic displays to increase visual detail and contrast in images and videos. These methods, which have been called both binocular tone mapping and dichoptic contrast enhancement , selectively emphasize contrast differently in the two eyes’ views. The visual system integrates these contrast differences into a unified percept, which is theorized to contain more contrast overall than each eye’s view on its own. As stereoscopic displays become increasingly common for augmented and virtual reality (AR/VR), dichoptic tone mapping is an appealing technique for imaging pipelines. We sought to examine whether a standard photographic technique, exposure bracketing, could be modified to enhance contrast similarly to dichoptic tone mapping. While assessing the efficacy of this technique with user studies, we also re-evaluated existing dichoptic tone mapping methods. Across several user studies; however, we did not find evidence that either dichoptic tone mapping or dichoptic exposures consistently increased subjective image preferences. We also did not observe improvements in subjective or objective measures of detail visibility. We did find evidence that dichoptic methods enhanced subjective 3D impressions. Here, we present these results and evaluate the potential contributions and current limitations of dichoptic methods for applications in stereoscopic displays.

Implementación de un Algoritmo para la Colorización de Video a Partir de una Imagen Muestra

En este artículo se propone la utilización de la técnica de colorización de video en escala de grises mediante la adaptación del algoritmo de colorización de imágenes. La colorización es una técnica fotográfica que se basa en transferir colores a una imagen en escala de grises, sepia o monocromática; en este trabajo se propone colorizar un video tomando el color de una imagen muestra, donde se comparan las luminancias de la imagen muestra con el video. La principal contribución de este trabajo consiste en la implementación del algoritmo para colorizar un video a partir de una imagen muestra, ya que anteriormente a esta investigación, esta técnica sólo funcionaba para imágenes. Los resultados de las pruebas muestran una colorización homogénea frame a frame, por secciones de video. This article proposes the use of the video colorization technique in grayscale by adapting the image coloring algorithm. Colorization is a photographic technique that is based on transferring colors to an image in grayscale, sepia or monochrome; in this paper is proposed coloring a video taking the color of a sample image, where the luminance of the image is compared with the video. The main contribution of this work is the implementation of the algorithm to coloring a video from a sample image, since prior to this research, this technique only worked for images. The results of the tests show a homogeneous colorization frame to frame, by sections of video.

Analysis of Middle Nubian Vessel-forming Technology Using Reflectance Transformation Imaging (RTI)

Reflectance Transformation Imaging (RTI) is a photographic technique used to generate digital surrogates of surfaces that can be viewed using virtual lighting coming from interactively set directions, enabling the close structural examination of objects under digital raking light. In this study, RTI was applied to Middle Nubian pottery from sites near the Second Nile Cataract that were excavated by the Scandinavian Joint Expedition to Sudanese Nubia in the early 1960s. The ceramic traditions under investigation are currently known as C-Group, Pan-Grave and Kerma. An overarching aim of the project is to assess the possibility of understanding the relationships between these groups through detailed analyses of their material traditions. Based on the hypothesis that technological traditions may be related to cultural heritage, RTI is applied in this study to observe morphological traces of ceramic vessel forming processes. Two technological groups were identified, one consistent with paddle-forming, and another consistent with hand-building on a mat-lined surface. These technological groups correspond very closely to cemetery distributions, which suggests that the different techniques may be specific to different potterymaking traditions. It is suggested that vessel forming-technology in the so-called C-Group tradition is distinct from that of the so-called Pan-Grave and Kerma traditions, and that the validity of the divisions between Nubian cultural groups should thus be further interrogated.

Verfünfungseffekt: Delving into the Enchanted World of Fivefold-portraits and Self-partitioning

Discovered during a media-archeological investigation into optical illusions, trick photography, and discarded memorabilia, the photo-multigraph technique opened the door to an enchanted world of cloned appearances orbiting in a self-reflective solar system. Shapeshifting into our preferred artistic medium, this turn-of-the-century photographic technique becomes the video-multigraph. It is bizarrely noteworthy that self-isolation would become not only the subject of the piece, but also – due to the unforeseen spread of a recently mutated virus – the prevailing circumstances under which the work was to be completed. In Verfünfungseffekt, we use the medium of video to create a kaleidoscopic portrait-in-motion where the perspective-shifting shards of ego are recorded in a synchronized performance of solipsist intersubjectivity. The video-multigraph allows for the compositing of tiny offsets in time-shifting delays applied to one, or several, of the mirrored selves – shattering the cloned perfection, as well as the conformity, of the multiple presences. This optical illusion necessitates reflection on how media alters our perceptions of time and space; it thereby arouses wonder about our place in existence. Keywords: Photo-multigraph, fivefold-portrait, mirror photography, video-multigraph, crisis of presence

Inventory and Protection of Photographs from the Julij Felaher Collection

Photographs bear visual memories of events, people, buildings and landscapes. The sensitivity of the materials used makes them a vulnerable part of cultural heritage, therefore their appropriate use and storage is ever more important. The work presented is based on an inventory of photographs from the Julij Felaher Collection (SI AS 1384) kept by the Archives of the Republic of Slovenia. In addition to basic information, the inventory sheet used also included reference to the type of photographic technique, the type of primary support, the type of damage, and an assessment of the preservation status. Based on the data obtained, physical protection of the photographs was carried out in order to enable their permanent storage.

The Perception and Views of Photographers on Artistic Photography in Turkey

The purposes of this study are to know generally the perception and view of photographers on artistic photography in a purposeful sample in Turkey. Participants were purposefully selected (purposive sample) from the community of photographers because it would represent diverse photographers in Turkey. The survey included 19 questions and divided into three parts. Findings of our study revealed that most of the participants were at their middle-age, male, married, university graduates, private sector employed, DSLR users, amateur/ traveling-landscape-portrait photographers, and they shoot their photos to be happy, to document anything, and for spending time (Hobby). They mainly thought that photos should be taken for documentary reasons. The creativity is mainly dependent on perspective (or photographic seeing). Good photography could be achieved with good photographic technique, a good photo is relying on the influence to the spectator, photo critics/reading should be mainly based on technique, the most influential movement is realism, artistic photography will improve, photography in future will improve, and some are participating in photographic projects. The results show that good grounds exist in Turkey to shape artistic photography for the needs of the 21st century.