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This paper presents methods for photo-realistic rendering using strongly spatially variant illumination captured from real scenes. The illumination is captured along arbitrary paths in space using a high dynamic range, HDR, video camera system with position tracking. Light samples are rearranged into 4-D incident light fields (ILF) suitable for direct use as illumination in renderings. Analysis of the captured data allows for estimation of the shape, position and spatial and angular properties of light sources in the scene. The estimated light sources can be extracted from the large 4D data set and handled separately to render scenes more efficiently and with higher quality. The ILF lighting can also be edited for detailed artistic control.

[pt] A indústria de confecção vem aplicando cada vez mais equipamentos que visam o aumento da produção aliado à qualidade elevada. Esses, em sua maioria, são máquinas automáticas na etapa que antecede o corte do tecido, ou seja, na criação, desenho e encaixe dos moldes (peças que compõem a roupa). Esse trabalho tem por objetivo o desenvolvimento de um equipamento para captura das imagens dos moldes, com o uso de apenas um sensor ótico. É proposto como uma alternativa para mesas digitalizadoras e scanners de mesa comerciais. Visto que a maioria das empresas possui seus moldes em chapas de acrílico ou cartolina, é interessante a existência de um dispositivo capaz de transportá-los para o computador. A partir daí, ele pode ser trabalhado como uma imagem digitalizada. É apresentado o processo de fabricação, com suas partes mecânicas, eletrônicas e algoritmos de controle e captura das imagens. O custo das imagens. O custo e desempenho final deve estar situado entre a mesa digitalizadora e a scanner de mesa comercial. Ao final, são traçados alguns comentários sobre os resultados alcançados. / [en] Confection companies are using more and more equipments to improve their productions. Not only concerned on the amount of products, but also for higher quality. Especially in process before fabric cutting, many of these machines are automatic. The reason for this work is to develop an equipment to capture images from molds, using only one optic sensor. It must be na alternative for digitizing tables and commercial scanners. Since mosto f the companies have their molds in acrylic plates and cardboards, it is necessary using a device to convert them to a to a digitized image an image. The final cost and execution must be situaded between the digitizing table and the commercial scanner. Some points are discussed about the results and, at the conclusion, about the possibility of becoming a commercial equipment.

For individuals with type 2 diabetes, diabetic foot ulcers represent a significant health issue and the wound care cost is quite high. Currently, clinicians and nurses mainly base their wound assessment on visual examination of wound size and the status of the wound tissue. This method is potentially inaccurate for wound assessment and requires extra clinical workload. In view of the prevalence of smartphones with high resolution digital camera, assessing wound healing by analyzing of real-time images using the significant computational power of today’s mobile devices is an attractive approach for managing foot ulcers. Alternatively, the smartphone may be used just for image capture and wireless transfer to a PC or laptop for image processing. To achieve accurate foot ulcer image assessment, we have developed and tested a novel automatic wound image analysis system which accomplishes the following conditions: 1) design of an easy-to-use image capture system which makes the image capture process comfortable for the patient and provides well-controlled image capture conditions; 2) synthesis of efficient and accurate algorithms for real-time wound boundary determination to measure the wound area size; 3) development of a quantitative method to assess the wound healing status based on a foot ulcer image sequence for a given patient and 4) design of a wound image assessment and management system that can be used both in the patient’s home and clinical environment in a tele-medicine fashion. In our work, the wound image is captured by the camera on the smartphone while the patient’s foot is held in place by an image capture box, which is specially design to aid patients in photographing ulcers occurring on the sole of their feet. The experimental results prove that our image capture system guarantees consistent illumination and a fixed distance between the foot and camera. These properties greatly reduce the complexity of the subsequent wound recognition and assessment. The most significant contribution of our work is the development of five different wound boundary determination approaches based on different computer vision algorithms. The first approach employs the level set algorithm to determine the wound boundary directly based on a manually set initial curve. The second and third approaches are the mean-shift segmentation based methods augmented by foot outline detection and analysis. These two approaches have been shown to be efficient to implement (especially on smartphones), prior-knowledge independent and able to provide reasonably accurate wound segmentation results given a set of well-tuned parameters. However, this method suffers from the lack of self-adaptivity due to the fact that it is not based on machine learning. Consequently, a two-stage Support Vector Machine (SVM) binary classifier based wound recognition approach is developed and implemented. This approach consists of three major steps 1) unsupervised super-pixel segmentation, 2) feature descriptor extraction for each super-pixel and 3) supervised classifier based wound boundary determination. The experimental results show that this approach provides promising performance (sensitivity: 73.3%, specificity: 95.6%) when dealing with foot ulcer images captured with our image capture box. In the third approach, we further relax the image capture constraints and generalize the application of our wound recognition system by applying the conditional random field (CRF) based model to solve the wound boundary determination. The key modules in this approach are the TextonBoost based potential learning at different scales and efficient CRF model inference to find the optimal labeling. Finally, the standard K-means clustering algorithm is applied to the determined wound area for color based wound tissue classification. To train the models used in the last two approaches, as well as to evaluate all three methods, we have collected about 100 wound images at the wound clinic in UMass Medical School by tracking 15 patients for a 2-year period, following an IRB approved protocol. The wound recognition results were compared with the ground truth generated by combining clinical labeling from three experienced clinicians. Specificity and sensitivity based measures indicate that the CRF based approach is the most reliable method despite its implementation complexity and computational demands. In addition, sample images of Moulage wound simulations are also used to increase the evaluation flexibility. The advantages and disadvantages of three approaches are described. Another important contribution of this work has been development of a healing score based mechanism for quantitative wound healing status assessment. The wound size and color composition measurements were converted to a score number ranging from 0-10, which indicates the healing trend based on comparisons of subsequent images to an initial foot ulcer image. By comparing the result of the healing score algorithm to the healing scores determined by experienced clinicians, we assess the clinical validity of our healing score algorithm. The level of agreement of our healing score with the three assessing clinicians was quantified by using the Kripendorff’s Alpha Coefficient (KAC). Finally, a collaborative wound image management system between the PC and smartphone was designed and successfully applied in the wound clinic for patients’ wound tracking purpose. This system is proven to be applicable in clinical environment and capable of providing interactive foot ulcer care in a telemedicine fashion.

El propósito de un método de segmentación es descomponer una imagen en sus partes constitutivas. Se han propuesto un gran número técnicas y algoritmos para realizar ésta tarea. Algoritmos de visión por computador, en particular de segmentación, que han sido utilizados con éxito en ambientes industriales, con colores e iluminación controlada, no obtienen resultados similares en contextos diferentes. Una alternativa para abordar problemas en que las condiciones de contorno no permiten una segmentación adecuada es incorporar información de profundidad. Las mejoras realizadas en el campo de las tecnologías de escaneo 3D han hecho posible que las cámaras basadas en el principio de tiempo de vuelo sean más accesibles. Las cámaras de tiempo de vuelo son dispositivos de captura que generan simultáneamente imágenes en tonos de grises e información 3D de la escena. La fusión de la información de profundidad junto con la informaci ́on de intensidad permite obtener descripciones de las escenas que tienen en cuenta tanto la geometr ́ıa de los objetos como la información de luminancia. En éste contexto, la segmentación de imágenes consiste en utilizar algoritmos que utilicen ambas fuentes de información y no sólo los niveles de intensidad. Con esta perspectiva el problema de segmentación puede ser formulado como la búsqueda de formas efectivas para particionar adecuadamente un conjunto de muestras con información de intensidad y distancia. Recientemente han sido propuestos diversos algoritmos de agrupamiento, tanto jerárquicos como particionales, para abordar el problema de segmentar objetos en imágenes de intensidad. En particular los métodos de agrupamiento espectral tienden a determinar la estructura subyacente en un conjunto de patrones, donde otros métodos convencionales por la disposición y características particulares de los agrupamientos, no obtienen los resultados esperados. La presente tesina se enfoca en la posibilidad de utilizar métodos de agrupamiento espectral en imágenes de rango y de intensidad para abordar problemas de segmentación complejos.

Digital Image-based Elasto-Tomography (DIET) is an emerging technology for non-invasive breast cancer screening. This technology relies on obtaining high resolution images of a breasts surface under high frequency actuation; typically 50-100Hz. Off-the-shelf digital cameras are unable to capture images directly at these speeds and current digital camera set-ups that are potentially capable of high speed image capture are either low in resolution, expensive, or occupy a volume too large to have them placed about the breast in a dense array. A method is presented for obtaining the required high speed image capture at a resolution of 1280x1024 (1.3 mega-pixels) and actuation frequency of 100Hz. The apparatus uses two Kodak CMOS KAC-9648 imaging sensors in combination with frame grabbers and the dSpace control system, to produce an automated image capture system. The final working system produced images that enabled effective 3D motion tracking of the surface of a silicon phantom actuated at 100Hz. The surface of the phantom was strobed at pre-selected phases from 0 to 360 degrees, and an image was captured for each phase. The times at which image capture occurred were calculated for a phase lag increment of 10 degrees resulting in an image effectively every 0.00028s for the actuator cycle of 0.01s. The comparison of the actual trigger times and pre-selected ideal trigger times gave a mean absolute error of 1.4%, thus demonstrating the accuracy of the final system.

The graduating paper focuses on the digital image capture method in criminalistic and also on its legal regulation and practical resort in the law enforcement institutions‘ investigations of criminal acts. The digital image capture is one of the methods of digital image capture in criminalistic. Its structure contains digital photography and digital video recording. The digital photography is used for strategical and investigative photography. The usage of the digital image capture method investigating the criminal acts is not against the provision of the Criminal Procedure Code. This method is not regulated by any other legal instrument. It often happens that the media captured by the digital camera under investigation is not attached to the criminal case. It is the violation of the Criminal Procedure Code. The digital photography is used in the pretrial investigation institutions‘ work but the traditional photography is used as well. There are no anticipated procedures how to protect the digital photography and files from the substitution, forgery and erasure. The digital information can be protected by establishing the procedures of the standard operations. One of the ways to protect it is electronic signature.

This diploma thesis deals with an image capturing by a CMOS image sensor and controlling of graphical LCD displays using specialized integrated circuits. A theoretical research on the topic and design of the system designed for ease of processing, transmitting and still images displaying based on this research is described in this work. The output of the work is complete the device realized.

[pt] O reconhecimento de humanos pela íris é um dos sistemas mais seguros de identificação biométrica e, motivou a construção de um protótipo de identificação humana baseada na estrutura da íris. O sistema construído é composto de um dispositivo de captura de imagens da íris humana e algoritmos para pré- processamento da imagem, para a representação e o reconhecimento. Cada um dos elementos que compõem o protótipo são avaliados a partir de dois bancos de dados de imagens de íris. Os resultados demonstraram que o dispositivo proposto e os modelos apresentados são capazes de realizar o reconhecimento humano através da íris de forma eficiente. / [en] The recognition of human beings for the Iris is one of the safest systems of biometric identification. This motivated the construction of a prototype for identification of human beings based on the structure of the Iris. The constructed system is composed of a device capable to capture images of the Iris and algorithms for image pre - processing, for the representation and recognition each element composing the prototype is evaluated using two data bases of Iris images. The results have demonstrated that the prototype and the presented models are capable to efficiently identify the human based on Iris structure.