217,537 research outputs found
Risk based bridge data collection and asset management and the role of structural health monitoring
Peer reviewedPostprin
Pushing the Limits of 3D Color Printing: Error Diffusion with Translucent Materials
Accurate color reproduction is important in many applications of 3D printing,
from design prototypes to 3D color copies or portraits. Although full color is
available via other technologies, multi-jet printers have greater potential for
graphical 3D printing, in terms of reproducing complex appearance properties.
However, to date these printers cannot produce full color, and doing so poses
substantial technical challenges, from the shear amount of data to the
translucency of the available color materials. In this paper, we propose an
error diffusion halftoning approach to achieve full color with multi-jet
printers, which operates on multiple isosurfaces or layers within the object.
We propose a novel traversal algorithm for voxel surfaces, which allows the
transfer of existing error diffusion algorithms from 2D printing. The resulting
prints faithfully reproduce colors, color gradients and fine-scale details.Comment: 15 pages, 14 figures; includes supplemental figure
Reflectance Transformation Imaging (RTI) System for Ancient Documentary Artefacts
This tutorial summarises our uses of reflectance transformation imaging in archaeological contexts. It introduces the UK AHRC funded project reflectance Transformation Imaging for Anciant Documentary Artefacts and demonstrates imaging methodologies
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Burn wound classification model using spatial frequency-domain imaging and machine learning.
Accurate assessment of burn severity is critical for wound care and the course of treatment. Delays in classification translate to delays in burn management, increasing the risk of scarring and infection. To this end, numerous imaging techniques have been used to examine tissue properties to infer burn severity. Spatial frequency-domain imaging (SFDI) has also been used to characterize burns based on the relationships between histologic observations and changes in tissue properties. Recently, machine learning has been used to classify burns by combining optical features from multispectral or hyperspectral imaging. Rather than employ models of light propagation to deduce tissue optical properties, we investigated the feasibility of using SFDI reflectance data at multiple spatial frequencies, with a support vector machine (SVM) classifier, to predict severity in a porcine model of graded burns. Calibrated reflectance images were collected using SFDI at eight wavelengths (471 to 851 nm) and five spatial frequencies (0 to 0.2 mm - 1). Three models were built from subsets of this initial dataset. The first subset included data taken at all wavelengths with the planar (0 mm - 1) spatial frequency, the second comprised data at all wavelengths and spatial frequencies, and the third used all collected data at values relative to unburned tissue. These data subsets were used to train and test cubic SVM models, and compared against burn status 28 days after injury. Model accuracy was established through leave-one-out cross-validation testing. The model based on images obtained at all wavelengths and spatial frequencies predicted burn severity at 24 h with 92.5% accuracy. The model composed of all values relative to unburned skin was 94.4% accurate. By comparison, the model that employed only planar illumination was 88.8% accurate. This investigation suggests that the combination of SFDI with machine learning has potential for accurately predicting burn severity
Spartan Daily, October 9, 1981
Volume 77, Issue 27https://scholarworks.sjsu.edu/spartandaily/6803/thumbnail.jp
Potential role of remote sensing in disaster relief management
Baseline or predisaster data which would be useful to decision making in the immediate postdisaster period were suggested for the six areas of public health concern along with guidelines for organizing these data. Potential sources of these data are identified. In order to fully assess the impact of a disaster on an area, information about its predisaster status must be known. Aerial photography is one way of acquiring and recording such data
Image-Processing Techniques for the Creation of Presentation-Quality Astronomical Images
The quality of modern astronomical data, the power of modern computers and
the agility of current image-processing software enable the creation of
high-quality images in a purely digital form. The combination of these
technological advancements has created a new ability to make color astronomical
images. And in many ways it has led to a new philosophy towards how to create
them. A practical guide is presented on how to generate astronomical images
from research data with powerful image-processing programs. These programs use
a layering metaphor that allows for an unlimited number of astronomical
datasets to be combined in any desired color scheme, creating an immense
parameter space to be explored using an iterative approach. Several examples of
image creation are presented.
A philosophy is also presented on how to use color and composition to create
images that simultaneously highlight scientific detail and are aesthetically
appealing. This philosophy is necessary because most datasets do not correspond
to the wavelength range of sensitivity of the human eye. The use of visual
grammar, defined as the elements which affect the interpretation of an image,
can maximize the richness and detail in an image while maintaining scientific
accuracy. By properly using visual grammar, one can imply qualities that a
two-dimensional image intrinsically cannot show, such as depth, motion and
energy. In addition, composition can be used to engage viewers and keep them
interested for a longer period of time. The use of these techniques can result
in a striking image that will effectively convey the science within the image,
to scientists and to the public.Comment: 104 pages, 38 figures, submitted to A
The feasibility of inventorying native vegetation and related resources form space photography
Photointerpretation of Gemini 4 photographs for inventorying native vegetatio
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