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Selected AbstractsTouchTone: Interactive Local Image Adjustment Using Point-and-SwipeCOMPUTER GRAPHICS FORUM, Issue 2 2010Chia-Kai Liang Recent proliferation of camera phones, photo sharing and social network services has significantly changed how we process our photos. Instead of going through the traditional download-edit-share cycle using desktop editors, an increasing number of photos are taken with camera phones and published through cellular networks. The immediacy of the sharing process means that on-device image editing, if needed, should be quick and intuitive. However, due to the limited computational resources and vastly different user interaction model on small screens, most traditional local selection methods can not be directly adapted to mobile devices. To address this issue, we present TouchTone, a new method for edge-aware image adjustment using simple finger gestures. Our method enables users to select regions within the image and adjust their corresponding photographic attributes simultaneously through a simple point-and-swipe interaction. To enable fast interaction, we develop a memory- and computation-efficient algorithm which samples a collection of 1D paths from the image, computes the adjustment solution along these paths, and interpolates the solutions to entire image through bilateral filtering. Our system is intuitive to use, and can support several local editing tasks, such as brightness, contrast, and color balance adjustments, within a minute on a mobile device. [source] Soil erosion assessment using geomorphological remote sensing techniques: an example from southern ItalyEARTH SURFACE PROCESSES AND LANDFORMS, Issue 3 2010Sergio Lo Curzio Abstract The aim of this study is to assess of the distribution and map the geomorphological effects of soil erosion at the basin scale identifying newly-formed erosional landsurfaces (NeFELs), by means of an integration of Landsat ETM 7+ remotely sensed data and field-surveyed geomorphological data. The study was performed on a 228·6,km2 -wide area, located in southern Italy. The study area was first characterized from a lithological, pedological, land-use and morpho-topographic point of view and thematic maps were created. Then, the georeferenced Landsat ETM 7+ satellite imagery was processed using the RSI ENVI 4.0 software. The processing consisted of contrast stretching, principal component analysis (PCA), decorrelation stretching and RGB false colour compositing. A field survey was conducted to characterize the features detected on the imagery. Particular attention was given to the NeFELs, which were located using a global positioning system (GPS). We then delimited the Regions of Interest (ROI) on the Landsat ETM 7+ imagery, i.e. polygons representing the ,ground-truth', discriminating the NeFELs from the other features occurring in the imagery. A simple statistical analysis was conducted on the digital number (DN) values of the pixels enclosed in the ROI of the NeFELs, with the aim to determine the spectral response pattern of such landsurfaces. The NeFELs were then classified in the entire image using a maximum likelihood classification algorithm. The results of the classification process were checked in the field. Finally, a spatial analysis was performed by converting the detected landsurfaces into vectorial format and importing them into the ESRI ArcViewGIS 9.0 software. Application of these procedures, together with the results of the field survey, highlighted that some ,objects' in the classified imagery, even if displaying the same spectral response of NeFELs, were not landsurfaces subject to intense soil erosion, thus confirming the strategic importance of the field-checking for the automatically produced data. During the production of the map of the NeFELs, which is the final result of the study, these ,objects' were eliminated by means of simple, geomorphologically-coherent intersection procedures in a geographic information system (GIS) environment. The overall surface of the NeFELs had an area of 22·9,km2, which was 10% of the total. The spatial analysis showed that the highest frequency of the NeFELs occurred on both south-facing and southwest-facing slopes, cut on clayey-marly deposits, on which fine-textured and carbonate-rich Inceptisols were present and displaying slope angle values ranging from 12° to 20°. The comparison of two satellite imageries of different periods highlighted that the NeFELs were most clearly evident immediately after summer tillage operations and not so evident before them, suggesting that these practices could have played an important role in inducing the erosional processes. Copyright © 2009 John Wiley & Sons, Ltd. [source] Analysis of skin images using texture descriptor by a combined statistical and structural approachINTERNATIONAL JOURNAL OF IMAGING SYSTEMS AND TECHNOLOGY, Issue 6 2007C. Umarani Abstract In this article, an attempt has been made to analyze various skin (textured) images. They are caused because of hot water, chemical, electrical, thermal, cigarette, etc. These images are analyzed using our texture representation scheme. Our approach uses a set of 92 texture primitives. They are tested for the presence of texture by a statistical design of experiments based approach [Ganesan and Bhattacharyya, Pattern Recogn 28 (1995), 99,105]. These texture primitives are concluded as the local descriptor and their distribution over the entire image is the global representation called texture primitive spectrum. The set of texture primitives and the texture primitive spectrums are successful for a number of Bench mark images (Brodatz, Texture,A photographic album for artists and designers, Reinbold, New York, 1968; Vistex, Available at http://www.white.media.mit.edu\vismod\imgery\Vision Texture, MIT Media Lab, 1995). Using the texture primitive spectrum, several texture images have been categorized as micro, macro, fine, and coarse and a trend is obtained. Similarly, a set of skin images affected by severe burn with many causes are analyzed. The severity has been quantified and concluded based on simple and weighted mean computed for the texture primitive spectrums. The extent of burn and hence the curing duration can be approximated from the results. The outcome of our experimentation with ground truth and the opinion from the experts are closely matching. © 2008 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 17, 359,366, 2007 [source] In vivo MRI using real-time production of hyperpolarized 129XeMAGNETIC RESONANCE IN MEDICINE, Issue 1 2008Bastiaan Driehuys Abstract MR imaging of hyperpolarized (HP) nuclei is challenging because they are typically delivered in a single dose of nonrenewable magnetization, from which the entire image must be derived. This problem can be overcome with HP 129Xe, which can be produced sufficiently rapidly to deliver in dilute form (1%) continuously and on-demand. We demonstrate a real-time in vivo delivery of HP 129Xe mixture to rats, a capability we now routinely use for setting frequency, transmitter gain, shimming, testing pulse sequences, scout imaging, and spectroscopy. Compared to images acquired using conventional fully concentrated 129Xe, real-time 129Xe images have 26-fold less signal, but clearly depict ventilation abnormalities. Real-time 129Xe MRI could be useful for time-course studies involving acute injury or response to treatment. Ultimately, real-time 129Xe MRI could be done with more highly concentrated 129Xe, which could increase the signal-to-noise ratio by 100 relative to these results to enable a new class of gas imaging applications. Magn Reson Med 60:14,20, 2008. © 2008 Wiley-Liss, Inc. [source] Automatic detection of circular structures in high-resolution satellite images of agricultural landARCHAEOLOGICAL PROSPECTION, Issue 1 2009Řivind Due Trier Abstract Archaeological sites are sometimes visible in satellite images as soil or crop marks. At best, the marks are distinct, but they tend to have less contrast with the background than many other patterns in the images. Consequently, reliable automated detection based on pattern recognition is very difficult. Our method detects circle-shaped soil and crop marks in the panchromatic band of high-resolution satellite images of agricultural fields. Such circular marks may be caused by burial mounds. In our approach, local contrast enhancement is applied in order to make weak marks more distinct. The image is then convolved with ring templates of varying sizes, giving high absolute values at candidate circular mark locations. Each candidate mark is presented to an operator, who may reject it. We tested our method on Quickbird images from southeast Norway. The number of detected candidate marks could be varied by changing a threshold value. A reasonable compromise between not detecting too many false rings and at the same time detecting as many true rings as possible, might be when the number of false detections is approximately seven times the number of true detections. In this case, 11 out of 15, or 73%, of the strong rings were detected, and 5 out of 10, or 50%, of the fairly strong rings were detected. This is 16 out of 25 of the strong and fairly strong rings, or 64%. Archaeologists state that the software tool we developed will be helpful for locating potential cultural heritage sites. Although it makes many false detections, it will relieve the operators from time-consuming manual inspection of entire images. Copyright © 2008 John Wiley & Sons, Ltd. [source] | |||||||||||||