21,825 research outputs found
Scanning medical images for screen presentation
The purpose of this article is to remove the myths and black art surrounding
electronic imaging and prove beyond doubt that any mind competent in the workings
of the human body is capable of producing good on-screen images from adequate
equipment. Note that in this day and age of SI units imaging still uses inches to
describe diagonal screen size and pixels per inch to describe resolution.peer-reviewe
High Dynamic Range Imaging for Preserving Chromaticity Information of Architectural Heritage
This proposal seeks to enhance the documentation of architectural heritage. Precise color information (i.e. chromaticity, excluding lighting effects) as an intrinsic property of materials has not been accurately documented in the scale of large surfaces for historical buildings. Every day the materials of historical buildings are decaying and their colors are fading. The colors we can see today will not be the same as future generations can see if we cannot preserve the chromaticity information. We propose to develop a method to assist in recording the chromaticity of historical buildings with low cost and high efficiency based on the emerging High Dynamic Range Imaging technology. The significance of it lies in that by recording the chromaticity information, we can achieve more complete documentation for historical buildings and can detect color change of the buildings when measurements are done in a regular basis, which will provide important information for preservation planning
Determining the Geographical Location of Image Scenes based on Object Shadow Lengths
Many studies have addressed various applications
of geo-spatial image tagging such as image retrieval,
image organisation and browsing. Geo-spatial image
tagging can be done manually or automatically with GPS
enabled cameras that allow the current position of the
photographer to be incorporated into the meta-data of an
image. However, current GPS-equipment needs certain time
to lock onto navigation satellites and these are therefore not
suitable for spontaneous photography. Moreover, GPS units
are still costly, energy hungry and not common in most
digital cameras on sale. This study explores the potential of,
and limitations associated with, extracting geo-spatial
information from the image contents. The elevation of the
sun is estimated indirectly from the contents of image
collections by measuring the relative length of objects and
their shadows in image scenes. The observed sun elevation
and the creation time of the image is input into a celestial
model to estimate the approximate geographical location of
the photographer. The strategy is demonstrated on a set of
manually measured photographs
Gabor Filter and Rough Clustering Based Edge Detection
This paper introduces an efficient edge detection method based on Gabor
filter and rough clustering. The input image is smoothed by Gabor function, and
the concept of rough clustering is used to focus on edge detection with soft
computational approach. Hysteresis thresholding is used to get the actual
output, i.e. edges of the input image. To show the effectiveness, the proposed
technique is compared with some other edge detection methods.Comment: Proc. IEEE Conf. #30853, International Conference on Human Computer
Interactions (ICHCI'13), Chennai, India, 23-24 Aug., 201
Studies of the effects of gravitational and inertial forces on cardiovascular and respiratory dynamics Semiannual status report, period ending 1 Oct. 1968
Gravitational and inertial force environment effects on cardiovascular and respiratory functions in dogs and chimpanzee
Scene Context Dependency of Pattern Constancy of Time Series Imagery
A fundamental element of future generic pattern recognition technology is the ability to extract similar patterns for the same scene despite wide ranging extraneous variables, including lighting, turbidity, sensor exposure variations, and signal noise. In the process of demonstrating pattern constancy of this kind for retinex/visual servo (RVS) image enhancement processing, we found that the pattern constancy performance depended somewhat on scene content. Most notably, the scene topography and, in particular, the scale and extent of the topography in an image, affects the pattern constancy the most. This paper will explore these effects in more depth and present experimental data from several time series tests. These results further quantify the impact of topography on pattern constancy. Despite this residual inconstancy, the results of overall pattern constancy testing support the idea that RVS image processing can be a universal front-end for generic visual pattern recognition. While the effects on pattern constancy were significant, the RVS processing still does achieve a high degree of pattern constancy over a wide spectrum of scene content diversity, and wide ranging extraneousness variations in lighting, turbidity, and sensor exposure
Interactive removal and ground truth for difficult shadow scenes
A user-centric method for fast, interactive, robust, and high-quality shadow removal is presented. Our algorithm can perform detection and removal in a range of difficult cases, such as highly textured and colored shadows. To perform detection, an on-the-fly learning approach is adopted guided by two rough user inputs for the pixels of the shadow and the lit area. After detection, shadow removal is performed by registering the penumbra to a normalized frame, which allows us efficient estimation of nonuniform shadow illumination changes, resulting in accurate and robust removal. Another major contribution of this work is the first validated and multiscene category ground truth for shadow removal algorithms. This data set containing 186 images eliminates inconsistencies between shadow and shadow-free images and provides a range of different shadow types such as soft, textured, colored, and broken shadow. Using this data, the most thorough comparison of state-of-the-art shadow removal methods to date is performed, showing our proposed algorithm to outperform the state of the art across several measures and shadow categories. To complement our data set, an online shadow removal benchmark website is also presented to encourage future open comparisons in this challenging field of research
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