Academic literature on the topic 'Images, Photographic – Digital techniques'
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Journal articles on the topic "Images, Photographic – Digital techniques"
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Kubáček, D., E. M. Pittich, and J. Zvolánková. "Digital Processing on Comets." Symposium - International Astronomical Union 161 (1994): 321–27. http://dx.doi.org/10.1017/s0074180900047598.
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Several digital techniques have been used to remove large-scale background variations caused by manufacturing and technology of the photographic processing on old photographic plates ORWO ZU-21. Suppression of these large-scale background variations improved the study of large-scale phenomena in cometary plasma tails and the determination of the solar wind characteristics. The results obtained from five images of the comet Bradfield 1987 XXIX have been compared. It has been shown that the simple digital techniques used were applicable also to photographic plates with images of lesser quality. They may be utilized in the treatment of old photographic plate archives.
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Maričević, Marko, Petra Ptiček, and Ivana Žganjar. "Recognition Model of Counterfeiting Digital Records of Biometric Photographic Image." Tehnički glasnik 16, no. 1 (February 4, 2022): 67–73. http://dx.doi.org/10.31803//tg-20210714171523.
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Biometric portrait as one of the most important means of identifying requirements through strict definition of dimensional relationships, preservation of realistic information about all technical characteristics of the photographic image, so that all biometric values can be digitized and used in recognition. The great variety and accessibility of applications for digital processing of digital record of a photographic image has enabled a visually convincing display of a forged photograph that leaves a different impression on the viewer and transmits a different, that is, a forged message. Due to the need to prove the authenticity of the digital record of the photographic image, methods have been developed for the analysis of the record that can detect deviations from the real record even when there are no visual signs of processing the photographic image. Not all analysis techniques can detect certain methods of photo manipulation, so multiple digital photography detection and analysis techniques need to be applied. In order to prove its authenticity, the scientific paper deals with methods for analysis and detection of forgery of digital photography with respect to the digital record and the structure of JPEG format.
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McConnell, James. "(320) Photographic and Post-processing Techniques for Horticultural Images." HortScience 41, no. 4 (July 2006): 1045A—1045. http://dx.doi.org/10.21273/hortsci.41.4.1045a.
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Numerous shooting and post-production techniques can be used to improve the quality of images used in horticultural publications. Certain lenses, lens attachments, and camera accessories are useful for enabling greater success in photographing plants. Small diffusers and reflectors allow the shooting of close-ups in the field, even when the sun is directly overhead. Shift lenses can be used to photograph trees at a closer distance without the extreme distortion of wide focal length lenses. Stitching of multiple images to produce panoramic shots can produce images with increased resolution, less distortion, and without the need for a wide-angle lens. Experiences with digital asset management management and post-production workflows are also presented.
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Basanth Kumar, Halaguru Basavarajappa, and Haranahalli Rajanna Chennamma. "Dataset for classification of computer graphic images and photographic images." IAES International Journal of Artificial Intelligence (IJ-AI) 11, no. 1 (March 1, 2022): 137. http://dx.doi.org/10.11591/ijai.v11.i1.pp137-147.
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<span lang="EN-US">The recent advancements in computer graphics (CG) image rendering techniques have made it easy for the content creators to produce high quality computer graphics similar to photographic images (PG) confounding the most naïve users. Such images used with negative intent, cause serious problems to the society. In such cases, proving the authenticity of an image is a big challenge in digital image forensics due to high photo-realism of CG images. Existing datasets used to assess the performance of classification models are lacking with: (i) larger dataset size, (ii) diversified image contents, and (iii) images generated with the recent digital image rendering techniques. To fill this gap, we created two new datasets, namely, ‘JSSSTU CG and PG image dataset’ and ‘JSSSTU PRCG image dataset’. Further, the complexity of the new datasets and benchmark datasets are evaluated using handcrafted texture feature descriptors such as gray level co-occurrence matrix, local binary pattern and VGG variants (VGG16 and VGG19) which are pre-trained convolutional neural network (CNN) models. Experimental results showed that the CNN-based pre-trained techniques outperformed the conventional support vector machine (SVM)-based classifier in terms of classification accuracy. Proposed datasets have attained a low f-score when compared to existing datasets indicating they are very challenging.</span>
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Kumar, Halaguru Basavarajappa Basanth, and Haranahalli Rajanna Chennamma. "Classification of Computer Graphic Images and Photographic Images Based on Fusion of Color and Texture Features." Revue d'Intelligence Artificielle 35, no. 3 (June 30, 2021): 201–7. http://dx.doi.org/10.18280/ria.350303.
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With the rapid advancement in digital image rendering techniques, allows the user to create surrealistic computer graphic (CG) images which are hard to distinguish from photographs captured by digital cameras. In this paper, classification of CG images and photographic (PG) images based on fusion of global features is presented. Color and texture of an image represents global features. Texture feature descriptors such as gray level co-occurrence matrix (GLCM) and local binary pattern (LBP) are considered. Different combinations of these global features are investigated on various datasets. Experimental results show that, fusion of color and texture features subset can achieve best classification results over other feature combinations.
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Almeida Magalhães, Cristina, Perrin Smith Neto, Pedro Américo Almeida Magalhães Júnior, and Clovis Sperb de Barcellos. "Separation of Isochromatics and Isoclinics Phasemaps for the Photoelastic Technique with use Phase Shifting and a Large Number of High Precision Images." Metrology and Measurement Systems 20, no. 1 (March 1, 2013): 127–38. http://dx.doi.org/10.2478/mms-2013-0012.
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Abstract Digital photoelasticity is an important optical metrology follow-up for stress and strain analysis using full-field digital photographic images. Advances in digital image processing, data acquisition, procedures for pattern recognition and storage capacity enable the use of the computer-aided technique in automation and facilitate improvement of the digital photoelastic technique. The objective of this research is to find new equations for a novel phase-shifting method in digital photoelasticity. Some innovations are proposed. In terms of phaseshifting, only the analyzer is rotated, and the other equations are deduced by applying a new numerical technique instead of the usual algebraic techniques. This approach can be used to calculate a larger sequence of images. Each image represents a pattern and a measurement of the stresses present in the object. A decrease in the mean errors was obtained by increasing the number of observations. A reduction in the difference between the theoretical and experimental values of stresses was obtained by increasing the number of images in the equations for calculating phase. Every photographic image has errors and random noise, but the uncertainties due to these effects can be reduced with a larger number of observations. The proposed method with many images and high accuracy is a good alternative to the photoelastic techniques.
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Morrison, Annie O., and Jerad M. Gardner. "Microscopic Image Photography Techniques of the Past, Present, and Future." Archives of Pathology & Laboratory Medicine 139, no. 12 (May 19, 2015): 1558–64. http://dx.doi.org/10.5858/arpa.2014-0315-ra.
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Context The field of pathology is driven by microscopic images. Educational activities for trainees and practicing pathologists alike are conducted through exposure to images of a variety of pathologic entities in textbooks, publications, online tutorials, national and international conferences, and interdepartmental conferences. During the past century and a half, photographic technology has progressed from primitive and bulky, glass-lantern projector slides to static and/or whole slide digital-image formats that can now be transferred around the world in a matter of moments via the Internet. Objective To provide a historic and technologic overview of the evolution of microscopic-image photographic tools and techniques. Data Sources Primary historic methods of microscopic image capture were delineated through interviews conducted with senior staff members in the Emory University Department of Pathology. Searches for the historic image-capturing methods were conducted using the Google search engine. Google Scholar and PubMed databases were used to research methods of digital photography, whole slide scanning, and smart phone cameras for microscopic image capture in a pathology practice setting. Conclusions Although film-based cameras dominated for much of the time, the rise of digital cameras outside of pathology generated a shift toward digital-image capturing methods, including mounted digital cameras and whole slide digital-slide scanning. Digital image capture techniques have ushered in new applications for slide sharing and second-opinion consultations of unusual or difficult cases in pathology. With their recent surge in popularity, we suspect that smart phone cameras are poised to become a widespread, cost-effective method for pathology image acquisition.
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Vieira, Filipe Gomes, Alexandre S. Scari, Pedro Américo Almeida Magalhães Júnior, Jordana S. R. Martins, and Cristina Almeida Magalhães. "Analysis of Stresses in a Tapered Roller Bearing Using Three-Dimensional Photoelasticity and Stereolithography." Materials 12, no. 20 (October 20, 2019): 3427. http://dx.doi.org/10.3390/ma12203427.
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Digital photoelasticity is an important segment of optical metrology for stress analysis by digital photographic images. Advances in digital image processing, data acquisition, standard recognition and data storage allow the utilization of computer-aided techniques in the automation and improvement of the digital photoelastic technique. The objective of this study is to develop new techniques using 3D rapid prototyping with transparent resins in digital photoelasticity. Some innovations are proposed (e.g., a tapered roller bearing built with 3D rapid prototyping with transparent resin and the final assembly with the specimens prototyped separately). A metrology study is carried out with the new techniques developed.
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Kwaku, Timothy. "Steganalysis Method for LSB Replacement Based On Local Gradient of Image Histogram." Advances in Multidisciplinary and scientific Research Journal Publication 10, no. 4 (November 30, 2022): 1–8. http://dx.doi.org/10.22624/aims/digital/v10n4p1.
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Today's encryption and decryption processes rely heavily on the use of modern stenography techniques, which ultimately lead to steganalysis. Because of its enormous benefits, such as the protection of information or the transport of data, steganalysis is increasingly becoming an interesting research topic. This investigation is primarily concerned with steganalysis techniques, more specifically those that are utilized on photographic images. In this research, the many LSB steganalysis processes that are supported by previous research are investigated further, along with the outcomes of those operations. According to the findings of this research, in order for modern steganography and steganalysis techniques to be more efficient, they need to fundamentally incorporate artificial intelligence and machine learning methodologies. Keywords: Steganalysis, LSB, Replacement, Local Gradient, Image Histogram
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Vucetic, C., D. Milovanovic, B. Dulic, I. Dimitrijevic, N. Kalezic, and G. Tulic. "Primena digitalne video tehnike u ortopediji." Acta chirurgica Iugoslavica 53, no. 4 (2006): 99–104. http://dx.doi.org/10.2298/aci0604099v.
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Digital video technologies are new and powerful tools with wide applications in orthopedic. Already integral to several common medical devices, digital images can be used for case documentation and presentation as well for diagnostic and surgical patient care information. Digital technologies allow easy manipulation of photographic, video and graphic materials in ways that were impossible with conventional techniques. Educational presentation has been transformed by use of computers and digital projectors. Understanding the basic foundations of digital imaging technology is important for effectively creating digital images, videos and presentations. In this review, we are going to discuss some of the issues that are raised by digital imaging in orthopedics, digital image processing, as well as, we are giving some recommendations for good quality of pre-, post- and intra-operative photographs in clinical use.
Dissertations / Theses on the topic "Images, Photographic – Digital techniques"
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Heiss, Detlef Guntram. "Calibrating the photographic reproduction of colour digital images." Thesis, University of British Columbia, 1985. http://hdl.handle.net/2429/24680.
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Colour images can be formed by the combination of stimuli in three primary colours. As a result, digital colour images are typically represented as a triplet of values, each value corresponding to the stimulus of a primary colour. The precise stimulus that the eye receives as a result of any particular triplet of values depends on the display device or medium used. Photographic film is one such medium for the display of colour images.
This work implements a software system to calibrate the response given to a triplet of values by an arbitrary combination of film recorder and film, in terms of a measurable film property. The implemented system determines the inverse of the film process numerically. It is applied to calibrate the Optronics C-4500 colour film writer of the UBC Laboratory for Computational Vision. Experimental results are described and compared in order to estimate the expected accuracy that can be obtained with this device using commercially available film processing.Science, Faculty of
Computer Science, Department of
Graduate
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Polignano, Sergio. "Do sensivel a significação : uma poetica da fotografia." [s.n.], 2006. http://repositorio.unicamp.br/jspui/handle/REPOSIP/284754.
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Orientador: Ernesto Giovanni BoccaraDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Artes
Made available in DSpace on 2018-08-07T06:14:51Z (GMT). No. of bitstreams: 1 Polignano_Sergio_M.pdf: 19138121 bytes, checksum: a2a1fa7467459819c2d2f07679e2acbd (MD5) Previous issue date: 2006
Resumo: Este trabalho propõe uma abordagem conceitual, dos diversos conteúdos da imagem fotográfica, a sua leitura e decodificação, que vai da sensibilidade aos significados. Apresenta uma proposta de análise que busca justificar e demonstrar a condição da poética (Arte) da fotografia. Nesse sentido, mostra o que de incomum pode deter o olhar que eterniza e o olhar que ressuscita, dando um real valor às imagens fotográficas, sejam elas quais forem e mostrem o que de mais importante possam mostrar, mantendo as informações ao longo do tempo. Desse modo, busca contribuir para uma melhor compreensão da época em que as fotografias foram feitas, dos cenários que as mesmas registram, de seus contextos, assim como das implicações e relações que tenham com as formas de expressão diferenciadas, que chamamos: Arte
Abstract: This work proposes an conceptual approach to the various contents of photographic image, its interpretation, and decoding, which goes from sensibility to signification; it brings a proposal for an analysis that can effectively justify and demonstrate the condition of poetry (art) of photography, showing which of its uncommon aspects can capture the point of view that makes it eternal and the point of view that resuscitates it, bringing the real value to photographic images, being them whatever they are, showing whatever most important subject they can hold, maintaining their image content throughout time, and serving for a better understanding of the time in which photographs were taken, their scenarios, contexts, implications, and relationships that they have with the different forms of expression that we cal!: Art
Mestrado
Mestre em Artes
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McQuade, Patrick John Art College of Fine Arts UNSW. "Visualising the invisible :articulating the inherent features of the digital image." Awarded by:University of New South Wales. Art, 2007. http://handle.unsw.edu.au/1959.4/43307.
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Contemporary digital imaging practice has largely adopted the visual characteristics of its closest mediatic relative, the analogue photograph, In this regard, new media theorist Lev Manovich observes that "Computer software does not produce such images by default. The paradox of digital visual culture is that although all imaging is becoming computer-based, the dominance of photographic and cinematic imagery is becoming even stronger. But rather than being a direct, "natural" result of photo and film technology, these images are constructed on computers" (Manovich 2001: 179), Manovich articulates the disjuncture between the technical processes involved in the digital image creation process and the visual characteristics of the final digital image with its replication of the visual qualities of the analogue photograph. This research addresses this notion further by exploring the following. What are the defining technical features of these computer-based imaging processes? Could these technical features be used as a basis in developing an alternative aesthetic for the digital image? Why is there a reticence to visually acknowledge these technical features in contemporary digital imaging practice? Are there historic mediated precedents where the inherent technical features of the medium are visually acknowledged in the production of imagery? If these defining technical features of the digital imaging process were visually acknowledged in this image creation process, what would be the outcome? The studio practice component of the research served as a foundation for the author's artistic and aesthetic development where the intent was to investigate and highlight four technical qualities of the digital image identified through the case studies of three digital artists, and other secondary sources, These technical qualities include: the composite RGB colour system of the digital image as it appears on screen; the pixellated microstructure of the digital image; the luminosity of the digital image as it appears on a computer monitor, and the underlying numeric and (ASCII based) alphanumeric codes of the image file which enables that most defining feature of the image file, that of programmability, Based on research in the visualization of these numeric and alphanumeric codes, digital images of bacteria produced through the use of the scanning electron microscope, were chosen as image content for an experimental body of work to draw the conceptual link between these numeric and alphanumeric codes of the image file and the coded genetic sequence of an individual bacterial entity.
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Carstens, Andries Theunis. "Digitising photographic negatives and prints for preservation." Thesis, Cape Peninsula University of Technology, 2013. http://hdl.handle.net/20.500.11838/1355.
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A DISSERTATION PRESENTED TO THE FACULTY OF INFORMATICS AND DESIGN
OF THE CAPE PENINSULA UNIVERSITY OF TECHNOLOGY IN FULFILMENT OF
THE REQUIREMENTS FOR THE DEGREE OF MAGISTER TECHNOLOGIAE
PHOTOGRAPHY
CAPE PENINSULA UNIVERSITY OF TECHNOLOGY
2013This study deals with the pitfalls and standards associated with the digitisation of photographic artefacts in formal collections. The popularity of the digital medium caused a rapid increase in the demand for converting images into digital files. The need for equipment capable of executing the task successfully, the pressure on collection managers to display their collections to the world and the demand for knowledge needed by managers and operators created pressure to perform optimally and often in great haste. As a result of the rush to create digital image files to be displayed and to be preserved, the decisions that are being made may be questionable. The best choice of file formats for longevity, setting and maintaining standards to guarantee quality digital files and consultation with experts in the field of digitisation as well as attention to best practices are important aspects which must be considered. In order to determine the state of affairs in countries with an advanced knowledge and experience in the field of digitisation, a comprehensive literature study was done. It was found that enough information exists to enable collection managers in South Africa to make well informed decisions to ensure a high quality of digital collection. By means of questionnaires, a survey was undertaken amongst selected Western Cape image preservation institutions to determine the level of knowledge of the managers who are required to make informed decisions. The questionnaire was designed to give insight into choices being made regarding the technical quality, workflow and best practice aspects of digitisation. Comparing the outcome of the questionnaires with best practices and recommended standards in countries with an advanced level of experience it was found that not enough of this experience and knowledge is used by local collection managers although readily available. In some cases standards are disregarded completely. The study also investigated by means of questionnaires the perception of the digital preservation of image files by fulltime photographic students and volunteer members of the Photographic Society of South Africa. It was found that uncertainty exist within both groups with regard to file longevity and access to files in five to ten year's time. Digitisation standards are set and maintained by the use of specially designed targets which enable digitising managers to maintain control over the quality of the digital content as well as monitoring of equipment performance. The use of these targets to set standards were investigated and found to be an accurate and easy method of maintaining control over the standard and quality of digital files. Suppliers of digitising equipment very often market their equipment as being of a high quality and being able to fulfil the required digitisation tasks. Testing selected digitising equipment by means of specially designed targets proved however that potential buyers of equipment in the high cost range should be very cautious about suppliers' claims without proof of performance. Using targets to verify performance should be a routine check before any purchase. The study concludes with recommendations of implementing standards and it points to potential future research.
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Phillips, Carlos. "Photographic transformations and greyscale pictures." Thesis, McGill University, 2006. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=101163.
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We have introduced a geometry which is invariant to certain forms of burning and dodging photographic prints. We then used this geometry to create invariant measurements which represent information which would not change given different photographic printing processes.The presented algorithm used properties of best-fit planes to represent a photograph. There are many other possibilities for measurements which would fit this framework. Further, the representation of photographs presented in this thesis could be combined with existing computer vision algorithms for such tasks as object recognition within photographs for which we do not know the development process.
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Gavard, Sandra. "Photo-graft : a critical analysis of image manipulation." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape9/PQDD_0015/MQ54990.pdf.
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Datodi, Mark. "Digital imaging: Creating new realities." Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 1999. https://ro.ecu.edu.au/theses/1253.
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More and more it is becoming increasingly difficult to discern photo reality from digital reality. Digital imagery is revolutionising photography and challenging preconceived notions of this art form. Over the years, photography has been viewed metaphorically as a window on the world and on the past. No longer however, is the creation of photographic imagery reliant upon its intrinsic relationship with reality. Using computer technology original photographic material can be altered, manipulated and seamlessly combined with other fictional imagery without obvious detection and with relative ease. The proliferation of digital imaging is producing two apparent crises for photography. The first is the perceived threat to photography, involving the fear that traditional photographic processes, methods and product will be superseded by manipulated digital images passing themselves off as real photographs. Added to these growing concerns for photography's longevity, is the prospect that viewers will no longer believe m photography as a deliverer of objective truth and that the medium itself will lose its power as a 'privileged conveyer of information'(Batchen, 1994,p.47). The second crisis pertains to ethical concerns that these digital simulations raise: copyright, moral rights and artistic integrity.
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Pedroso, Anderson Antonio. "Vilém flusser : de la philosophie de la photographie à l’univers des images techniques." Thesis, Sorbonne université, 2020. http://www.theses.fr/2020SORUL103.
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La pensée de Vilém Flusser (1920-1991) a donné lieu à une abondante bibliographie critique sur ses apports en matière de communication, où son pari d’une « nouvelle imagination » fait tenir ensemble l’art, la science et la technologie, sous l’égide de sa philosophie de la photographie. L’archéologie de sa pensée, proposée ici, a été construite en tenant compte de l’ancrage disciplinaire de ses travaux dans les théories de la communication et des médias : elle s’est intéressée à la notion de l’art que Flusser développe au cours de son parcours, afin de saisir le déploiement de cette dimension artistique, son statut et ses contours, aussi bien que sa portée. La notion d’art chez Flusser est indissociablement liée à l’histoire : l’expérience traumatisante de l’exil est devenue centrale dans sa pensée critique de tout totalitarisme. L’ensemble de pratiques et de savoirs qui fondent son rapport au monde et qui informent sur l’élaboration de sa pensée sont travaillés par une Kulturgeschichte, vue depuis la perspective d’une « post-histoire ». Mais il y a en particulier une pensée du jeu, ludique, où l’objectif est moins de jouer à l’intérieur des règles établies que de déjouer les règles, de « jouer pour changer le jeu ». Autrement dit, il s’agit d’une pensée radicalement dialogique et polyphonique, dont la Kommunikologie, façonnée comme métathéorie, représente l’essor de Flusser. Sa trajectoire historique et les savoirs qui lui sont associés contribuent à la construction d’une pensée cybernétique qui projette les lignes fondamentales d’une Kunstwissenschaft, dans laquelle il propose une sorte d’iconoclasme sans renoncer aux imagesThe thought of Vilém Flusser (1920-1991) has given rise to an abundant critical bibliography on his contributions in the field of communication, where his wager on a "new imagination" brings together art, science and technology, under the aegis of his philosophy of photography. The archaeology of his thought, proposed here, is constructed alongside this disciplinary underpinning of his work in the theories of communication and media: it involves the notion of art that Flusser developed during his career, in order to grasp the deployment of this artistic dimension, its status and its contours, in his thought. Flusser's notion of art is inseparably linked to history: the traumatic experience of exile becames central in his critical thinking regarding all totalitarianism. The practices and knowledge that underpin his relationship to the world and guide the development of his conception are worked on by a Kulturgeschichte, seen from the perspective of a "post-history". But there is, in particular, a playful thinking of the game, where the objective is less to play within the established rules than to thwart the rules, to "play to change the game". In other words, it is a radically dialogical and polyphonic way of thinking, whose Kommunikologie, shaped as metatheory, directs the development of Flusser's work. His historical trajectory and the knowledge associated with it contribute to the construction of a cybernetic way of thinking that sketches the fundamental lines of a Kunstwissenschaft, in which he proposes a kind of iconoclasm without giving up images
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Van, der Westhuizen Christo Carel. "Efficient registration of limited field of view ocular fundus imagery." Thesis, Stellenbosch : Stellenbosch University, 2013. http://hdl.handle.net/10019.1/85633.
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Thesis (MScEng)-- Stellenbosch University, 2013.ENGLISH ABSTRACT: Diabetic- and hypertensive retinopathy are two common causes of blindness that can be prevented by managing the underlying conditions. Patients suffering from these conditions are encouraged to undergo regular examinations to monitor the retina for signs of deterioration. For these routine examinations an ophthalmoscope is used. An ophthalmoscope is a relatively inexpensive device that allows an examiner to directly observe the ocular fundus (the interior back wall of the eye that contains the retina). These devices are analog and do not allow the capture of digital imagery. Fundus cameras, on the other hand, are larger devices that o er high quality digital images. They do, however, come at an increased cost and are not practical for use in the eld. In this thesis the design and implementation of a system that digitises imagery from an ophthalmoscope is discussed. The main focus is the development of software algorithms to increase the quality of the images to yield results of a quality closer to that of a fundus camera. The aim is not to match the capabilities of a fundus camera, but rather to o er a cost-e ective alternative that delivers su cient quality for use in conducting routine monitoring of the aforementioned conditions. For the digitisation the camera of a mobile phone is proposed. The camera is attached to an ophthalmoscope to record a video of an examination. Software algorithms are then developed to parse the video frames and combine those that are of better quality. For the parsing a method of rapidly selecting valid frames based on colour thresholding and spatial ltering techniques are developed. Registration is the process of determining how the selected frames t together. Spatial cross-correlation is used to register the frames. Only translational transformations are assumed between frames and the designed algorithms focuses on estimating this relative translation in a large set of frames. Methods of optimising these operations are also developed. For the combination of the frames, averaging is used to form a composite image. The results obtained are in the form of enhanced grayscale images of the fundus. These images do not match those captured with fundus cameras in terms of quality, but do show a signi cant increase when compared to the individual frames that they consists of. Collectively a set of video frames can cover a larger region of the fundus than what they do individually. By combining these frames an e ective increase in the eld of view is obtained. Due to low light exposure, the individual frames also contain signi cant noise. In the results the noise is reduced through the averaging of several frames that overlap at the same location.
AFRIKAANSE OPSOMMING: Diabetiese- en hipertensiewe retinopatie is twee algemene oorsake van blindheid wat deur middel van die behandeling van die onderliggende oorsake voorkom kan word. Pasiënte met hierdie toestande word aangemoedig om gereeld ondersoeke te ondergaan om die toestand van die retina te monitor. 'n Oftalmoskoop word gebruik vir hierdie roetine ondersoeke. 'n Oftalmoskoop is 'n relatiewe goedkoop, analoë toestel wat 'n praktisyn toelaat om die agterste interne wand van die oog the ondersoek waar die retina geleë is. Fundus kameras, aan die ander kant, is groter toestelle wat digitale beelde van 'n hoë gehalte kan neem. Dit kos egter aansienlik meer en is dus nie geskik vir gebruik in die veld nie. In hierdie tesis word die ontwerp en implementering van 'n stelsel wat beelde digitaliseer vanaf 'n oftalmoskoop ondersoek. Die fokus is op die ontwikkeling van sagteware algoritmes om die gehalte van die beelde te verhoog. Die doel is nie om die vermoëns van 'n fundus kamera te ewenaar nie, maar eerder om 'n koste-e ektiewe alternatief te lewer wat voldoende is vir gebruik in die veld tydens die roetine monitering van die bogenoemde toestande. 'n Selfoonkamera word vir die digitaliserings proses voorgestel. Die kamera word aan 'n oftalmoskoop geheg om 'n video van 'n ondersoek af te neem. Sagteware algoritmes word dan ontwikkel om die videos te ontleed en om videogrepe van goeie kwaliteit te selekteer en te kombineer. Vir die aanvanklike ontleding van die videos word kleurband drempel tegnieke voorgestel. Registrasie is die proses waarin die gekose rame bymekaar gepas word. Direkte kruiskorrelasie tegnieke word gebruik om die videogrepe te registreer. Daar word aanvaar dat die videogrepe slegs translasie tussen hulle het en die voorgestelde registrasie metodes fokus op die beraming van die relatiewe translasie van 'n groot versameling videogrepe. Vir die kombinering van die grepe, word 'n gemiddeld gebruik om 'n saamgestelde beeld te vorm. Die resultate wat verkry word, word in die vorm van verbeterde gryskleur beelde van die fundus ten toon gestel. Hierdie beelde is nie gelykstaande aan die kwaliteit van beelde wat deur 'n fundus kamera geneem is nie. Hulle toon wel 'n beduidende verbetering teenoor individuele videogrepe. Deur dat 'n groot versameling videogrepe wat gesamentlik 'n groter area van die fundus dek gekombineer word, word 'n e ektiewe verhoging van data in die area van die saamgestelde beeld verkry. As gevolg van lae lig blootstelling van die individuele grepe bevat hul beduidende ruis. In die saamgestelde beelde is die ruis aansienlik minder as gevolg van 'n groter hoeveelheid data wat gekombineer is om sodoende die ruis uit te sluit.
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Suen, Tsz-yin Simon, and 孫子彥. "Curvature domain stitching of digital photographs." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2007. http://hub.hku.hk/bib/B38800901.
Full textBooks on the topic "Images, Photographic – Digital techniques"
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Davies, Adrian. Digital imaging for photographers. 3rd ed. Oxford: Focal Press, 1998.
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Barboza, Pierre. Les nouvelles images. Paris: Editions d'art Somogy, 1997.
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Creative digital photography. Newton Abbot: David & Charles, 2002.
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Phil, Fennessy, ed. An introduction to electronic imaging for photographers. Oxford [England]: Focal Press, 1994.
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Davies, Adrian. Electronic imaging for photographers. 2nd ed. Oxford [England]: Focal Press, 1996.
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Busselle, Michael. Creative digital photography. New York: Amphoto Books, 2001.
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Bavister, Steve. Digital photography: A no-nonsense, jargon-free guide for beginners. London: Collins & Brown, 2000.
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Digital photography: A no-nonsense, jargon-free guide for beginners. London: Collins & Brown, 2000.
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Slaughter, Scott. Easy digital photography. 2nd ed. Grand Rapids, Mich: Abacus, 1999.
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Digital camera design guide. Albany, NY: Coriolis Group Books, 1998.
Find full textBook chapters on the topic "Images, Photographic – Digital techniques"
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Katsaggelos, Aggelos K. "Restoration of Scanned Photographic Images." In Digital Image Restoration, 209–38. Berlin, Heidelberg: Springer Berlin Heidelberg, 1991. http://dx.doi.org/10.1007/978-3-642-58216-5_8.
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Aronoff, Janee, Nyree Costello, Gavin Cromhout, and Vikas Shah. "Toning and Aging Images." In Photoshop 7 Professional Photographic Techniques, 113–40. Berkeley, CA: Apress, 2002. http://dx.doi.org/10.1007/978-1-4302-0779-5_6.
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Murry, Natalie. "Adding Photographic Elements to a Composite." In Digital Forensic Art Techniques, 167–85. Boca Raton, FL : CRC Press, [2018]: CRC Press, 2018. http://dx.doi.org/10.4324/9781351047166-10.
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Değirmenci, Koray. "Photographic Images in the Digital Era." In The Palgrave Handbook of Image Studies, 515–32. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-71830-5_31.
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Aronoff, Janee, Nyree Costello, Gavin Cromhout, and Vikas Shah. "Adding and Subtracting Features from your Images." In Photoshop 7 Professional Photographic Techniques, 45–78. Berkeley, CA: Apress, 2002. http://dx.doi.org/10.1007/978-1-4302-0779-5_4.
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Aronoff, Janee, Nyree Costello, Gavin Cromhout, and Vikas Shah. "Preparing Images for Print and Optimizing for the Web." In Photoshop 7 Professional Photographic Techniques, 245–61. Berkeley, CA: Apress, 2002. http://dx.doi.org/10.1007/978-1-4302-0779-5_12.
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Rubinstein, Daniel. "Graven Images." In Fragmentation of the Photographic Image in the Digital Age, 100–114. New York, NY: Routledge, 2020. | Series: [Routledge history of photography]: Routledge, 2019. http://dx.doi.org/10.4324/9781351027946-8.
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Yahya, Abid. "Steganography Techniques." In Steganography Techniques for Digital Images, 9–42. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-78597-4_2.
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Colebrook, Claire. "Images Without Worlds." In Fragmentation of the Photographic Image in the Digital Age, 11–27. New York, NY: Routledge, 2020. | Series: [Routledge history of photography]: Routledge, 2019. http://dx.doi.org/10.4324/9781351027946-2.
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Li, Zhaohong, Jingyu Ye, and Yun Qing Shi. "Distinguishing Computer Graphics from Photographic Images Using Local Binary Patterns." In Digital Forensics and Watermaking, 228–41. Berlin, Heidelberg: Springer Berlin Heidelberg, 2013. http://dx.doi.org/10.1007/978-3-642-40099-5_19.
Full textConference papers on the topic "Images, Photographic – Digital techniques"
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Kovesi, Peter. "Phase Preserving Tone Mapping of Non-Photographic High Dynamic Range Images." In 2012 International Conference on Digital Image Computing: Techniques and Applications (DICTA). IEEE, 2012. http://dx.doi.org/10.1109/dicta.2012.6411698.
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Hill, Rodrigo, Marcos Steagall, and David van Vliet. "Augmenting Community Narratives: An Exploration of Lens-based Image and Publication Design." In LINK 2021. Tuwhera Open Access, 2021. http://dx.doi.org/10.24135/link2021.v2i1.84.
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This presentation proposal advances a pedagogical case study that focuses on innovative ways of promoting visual literacy for undergraduate students through lens-based image-making and digital technologies. The curriculum was designed to be delivered throughout an academic semester at Auckland University of Technology South Campus, Manukau City, Aotearoa New Zealand. The content is formatted for first-year students of the Diploma in Arts endorsed in Communication Design. The Diploma in Arts is appealing to students who may be seeking a shorter design qualification. In addition, the programme provides for students who have not met or have narrowly missed University Entrance (UE) criteria. The presentation focuses on the structure and contents of the pedagogical experience where lecturers and students are connected in the design studio through agency and literacy rather than just observing pedagogical prescriptions. In this active environment, the hidden curriculum that deals with the participant's cultural background and natural epistemologies is valued and validated. In creating the engagement for visual literacy, the brief requires students to consider aspects of community, taking the role of a storyteller equipped with skills to create visual content that is meaningful and actual. The course is divided into two parallel design studio approaches: one that deals with visual literacy through the photographic image and practice; and the other is concerned with aspects of the nature of the media, augmented reality and image dissemination in digital platforms. The first area focused on visual literacy through photographic practice, using the politics of photographic language and representation, employing portraiture analysis and image creation. This approach encompasses the conceptual aspects associated with photographic images and the technical aspects of lens-based image-making. The second area focused on understanding digital media, the application of tools and how to take advantage of the interactive environment to promote awareness and reflect change in the community. This part of the brief intended to create an understanding of the issues associated with online environments, providing students with skills to operate creatively and fluidly in response to the fast-paced nature of online image-sharing platforms. Within this context, techniques of digital image construction and manipulation were investigated in the light of industry applications and best practice workflows. These learning areas were underpinned by an online blog where students actively recorded their design process, tests, and contextual influences that impacted their design practice. The studio environment fostered an inclusive and participatory form of teaching and learning and employed students' smartphones as an accessible tool to produce and understand images. The project contributes to knowledge about the design studio through a framework for Visual literacy and media education, where students learn principles of photography practice and digital technologies. It contributes to reflections about the use of mobile phone technologies as a common entry way apparatus to visual literacy and imagery generator.
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Regidor Ros, José Luis, Clara Portilla Romero, Juan Valcárcel Andrés, and Pilar Roig Picazo. "Pictorial reconstruction of Palomino’s ceiling by digital techniques." In RECH6 - 6th International Meeting on Retouching of Cultural Heritage. València: Editorial Universitat Politècnica de València, 2021. http://dx.doi.org/10.4995/rech6.2021.13528.
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The case of the frescos by Palomino in the church of Santos Juanes in Valencia is a challenge that requires new alternatives to traditional mural restoration. Part of the paintings burnt in 1936 were detached and partly relocated in the vault afterwards. One third of the paintings, which were not detached, have been restored. A new phase of intervention has now begun, using a system of aesthetic reconstruction generated by digital images. This technique, already used successfully in a previous intervention, aims to recover the pictorial and functional atmosphere of this religious space.In order to fulfil the goal of trying to give a global solution to Palomino's work, it is necessary to find a chromatic solution to the apse of the church due to the absence of its original frescos. We propose the use of video mapping based on a historical black and white photograph taken by J. Alcon before the fire. Taking chromatic and iconographic references from other pictorial works that are in the same space-time context as the original painting and were executed by the same author, an aesthetic approach to the work would be made through the technique of video mapping. Mapping allows the viewer to see the pictorial and functional values of the artwork, without using an invasive form, and favours a vision of its historical-artistic context. Without physically altering the heritage, the final audiovisual presentation can reach multiple levels of information, helping the observer to understand, for example, the technique and pictorial materiality of the frescos and, at the same time, to discover the different iconographic representations.On the other hand, the successful system realised in the first phase was based on digital treatment of another historical photograph in black and white. This procedure was carried out in several ways such as straightening, rectifying and scaling of historical photograph. After the previous process, the following step was a digital colouring based on the superposition of the captures of the existing fragments to the picture taken by J. Alcon, always taking the colours of the original painting as a reference. The creation of the virtual final image also requires colour management calculations to be transformed into a printed or projected reality. The last step is to print and transfer the image to the wall. This was done with Papelgel®, a temporary support for the transfer of inkjet and pigmented printing inks. In this case the main novelty is the use of an adhesive pattern which improves the transfer of digital print fidelity and maintains the breathability of the wall. In the current phase of intervention, this system is intended to be applied to the rest of the vault once the detached fragments have been relocated to their original position.This project is an important attempt in the search for perfect harmony between the different computing elements. Information technologies offer a new and wide range of possibilities to preserve cultural heritage and participate directly in the intervention processes required for their conservation and restoration.
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Ferranti, Tomás, Asla Medeiros e Sá, and Paulo Cezar Pinto Carvalho. "Single Image 3D Building Reconstruction Using Rectangles Parallel to an Axis." In Workshop de Visão Computacional. Sociedade Brasileira de Computação - SBC, 2021. http://dx.doi.org/10.5753/wvc.2021.18906.
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Historic photographic collections are valuable documents of urban evolution through time. Many historic buildings documented in such collections may have been demolished or changed over time. Digital modeling such buildings may be challenging due to the reduced amount of information available that may be limited to a few images and/or schematic drawings. This paper presents a method to create a 3D set of rectangles that approximates elements of a scene (such as walls, floors, and roofs) from a single image. Using a pinhole camera model, the extraction of geometry and texture of planes parallel to an axis can be obtained after a camera calibration step that recovers intrinsic parameters of the model. Results show that a good visualization of the scene can be created, using the proposed technique, from a single image.
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Vereshchagin, Vladislav, Ekaterina Pukhova, and Margarita Khokhlova. "Combination of AM and FM screening as security printed feature." In 10th International Symposium on Graphic Engineering and Design. University of Novi Sad, Faculty of technical sciences, Department of graphic engineering and design,, 2020. http://dx.doi.org/10.24867/grid-2020-p45.
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Protection of goods and packaging from counterfeiting and copying, tracking their movement requires improvement of existing labeling and security methods and the development of new ones. Making changes to the image at the prepress stage is the cheapest and easiest way of protection compared to using special printing techniques, special substrates, and inks or additional tags such as RFID. In the article, we suggest a new method to create security printed features, identify them in prints, and confirm the authenticity of the image. The method uses a combination of regular (AM) and stochastic (FM) screening in one image. There are two ways of separating images for AM and FM screening. First is to choose several random intervals in shadows of image tonal distribution and in accordance with values in these intervals original image is separated into two. The second is to separate by structure, for example, use FM screening on edges or textures. We tried Canny edge detector and local binary patterns. By using random values as the parameters, it is possible to generate unique print runs or even individual prints using digital printing. And large variability in the areas of separation gives reason to consider that the suggested method is reliable. Fourier analysis in the suggested method allows not only to detect the presence of security printed features but also to confirm the authenticity of the image on a print. Authentication is implemented by obtaining a digital image of the print by scanning or photographing and comparing the spectral composition of the original image and the digital image of the print. An expert survey showed that after our method presence of a combination of AM and FM screening in images on prints is barely visible. As a result, this method can be used to protect packaging labels with images from copying.
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Mantha, S., L. Mongeau, and T. Siegmund. "Dynamic Digital Image Correlation of a Dynamic Physical Model of the Vocal Folds." In ASME 2005 International Mechanical Engineering Congress and Exposition. ASMEDC, 2005. http://dx.doi.org/10.1115/imece2005-81457.
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An experimental study of the vibratory deformation of the human vocal folds was conducted. Experiments were performed using model vocal folds [1, 2], Fig. 1, made of silicone rubber implemented into an air supply system, Fig. 2. The material used to cast the model is an isotropic homogeneous material, [3] with a tangent modulus E=5 kPa at ε = 0, i.e. elastic properties similar to those of the human vocal fold cover [4]. The advantages of the use of model larynx systems over the use of excised larynges include easy accessibility to fundamental studies of the vocal fold vibration without invasive testing. Acoustic analysis of voice or electroglottography provide certain insight into voice production processes but optical techniques for the study of vocal fold vibrations have drawn considerable attention. Videoendoscopy, stroboscopy, high-speed photography, and kymography have shown to provide a visual impression of vocal fold dynamics but are limited in providing insight into the fundamental deformation processes of the vocal folds. Quantitative measures of deformation have been conducted through micro-suture techniques but are invasive and allows for measurements of only view image points. Laser triangulation is non-invasive but is limited to only one local measurement point. Here, digital image correlation technique with the software VIC 3D [5] is applied. For the experimental set-up see Fig. 2. The analysis consists of (1) stereo correlation to obtain in-plane displacements and (2) stereo triangulation step to obtain out-of-plane deformation. For the stereo correlation images of the object at two different stages of deformation are compared. A point in the image of the undeformed object is matched with the corresponding point in the deformed stage. “Subsets” of digital images are traced via their gray value distribution from the undeformed reference image to the deformed image. The uniqueness of the matching is enabled by the creation of a speckle pattern on the object’s surface. Here, a white pigment is mixed into the silicone rubber and subsequently black enamel paint is sprayed onto the superior surface of the vocal folds. The stereo triangulation requires two images of the object at each stage of deformation. These are obtained in a single CCD frame by placing a beam splitter in the optical axis between camera and object. These images provide a “left” and “right” view of the model larynx. Thus, the deformed shape of the vocal folds can be obtained. The method allows for noninvasive measurement of the full-field displacement fields. Images of the superior surface of the model larynx are obtained by the use of a high speed digital camera with a frame rate of 3000 frames per second allowing for more than 30 image frames for each vibration cycle. For the 3D digital image correlation analysis two images of the object are obtained for each time instance as a beam splitter is placed in the optical axis between the camera and the model larynx. Phonation frequencies and onset pressure are given in Fig. 3, showing that the model larynx behavior is close to actual physiological data. Figs 4(a) and (b) provide superior views of the model larynx at maximum glottal opening and at glottal closure, respectively. As one example of measured strain fields, Figs 5(a) and (b) depict the distributions of the transverse strain component, on the glottal surface in a contour plot on the deformed superior surface. The knowledge of the distribution of this strain component is relevant to the assessment of the impact of vocal fold collision on potential tissue damage. In the position of maximum opening the vocal folds are deformed by a combination of a bulging-type deformation and the opening movement. At this time instance, the transverse strains at the medial surface are found to be negative, an indication of Poisson’s deformation. During the closing stage, vocal folds collide and simultaneously a mode 3 vibration pattern emerges. Closure of the glottal opening is not complete and two incomplete closure areas are formed during the closure stage. These open areas are located at the anterior and posterior ends of the model larynx, see Fig. 4(b). The finding of this type of incomplete closure is agreement with both actual glottal measurements [6] and 3D finite element simulations of [7]. Transverse strains during that stage are now positive and considerably larger that during the opening stage. Finally, Fig. 6 depicts the time evolution of the out of plane displacements along the medial surface for the closing phase and Fig. 7 depicts the maximum values of the longitudinal strain (at the coronal section of the medial surface) in dependence of the flow rate. These examples of measurements indicate that the DIC method is promising for studies of vocal fold dynamics.
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Schwall, Matthew L., Daniel E. Rosenfeld, and Joel C. Wilson. "Enhanced Tire Mark Visualization Using Polarization Imaging." In ASME 2013 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/imece2013-63953.
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Accident reconstructions often rely on measurements of tire marks left on the roadway surface. However, accurate identification and measurement of these marks can be challenging when the marks are faint, as is often the case with braking marks left by vehicles equipped with anti-lock (ABS) brakes. This paper describes an image processing technique that exploits differences in the polarization of reflected light to create images that significantly enhance tire mark visualization. The technique requires multiple photographs taken from the same perspective, but with a polarizing filter oriented at different angles. Based on these digital images, the state of polarization of light can be determined for each pixel. A new image can then be created in which the intensity of the image is proportional to the state of light polarization. Results are presented using ABS tire marks, and demonstrate that under certain conditions the resulting image more clearly differentiates tire marks than conventional photographs or even contrast enhanced conventional photographs.
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Reinhard, Erik, Michael Stark, Peter Shirley, and James Ferwerda. "Photographic tone reproduction for digital images." In the 29th annual conference. New York, New York, USA: ACM Press, 2002. http://dx.doi.org/10.1145/566570.566575.
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CHURCH, PHIL, DOUG KIRKPATRICK, PHIL OTTLEY, MARCUS DEAR, and ROB KING. "DEVELOPMENT OF HIGH SPEED PHOTOGRAPHY TECHNIQUE FOR UNDEX APPLICATIONS." In 32ND INTERNATIONAL SYMPOSIUM ON BALLISTICS. Destech Publications, Inc., 2022. http://dx.doi.org/10.12783/ballistics22/36047.
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This paper describes recent experimental development of high speed photography (HSP) applied to UNDer water Explosive (UNDEX) trials. The imaging technique adopted used overhead mirrors and a Perspex® plate on the surface of the water in a tank holding 11,000 litres of water. The HSP has identified the shock wave velocity, shape and timescales and the bubble dynamics as well as the interaction with the target (i.e. Glass reinforced panel (GFRP) composite panel). Charge sizes ranged from 40-140g of PE4 explosive and good images were obtained of the target response. Improvements to the technique will be higher fidelity to enable Digital Image Correlation (DIC) measurements for the panel as well as improved target fixings to prevent lateral motion so that damage could be induced in the panel. The technique can also be used on bigger scale UNDEX trials.
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Wang, Haichao, Ni Chen, Jingdan Liu, and Guohai Situ. "Light field imaging based on defocused photographic images." In Digital Holography and Three-Dimensional Imaging. Washington, D.C.: OSA, 2016. http://dx.doi.org/10.1364/dh.2017.w3a.3.
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