An improved 3D imaging system for dimensional quality inspection of rolled products in the metal industry

Measurement, inspection and quality control in industry have benefited from 3D techniques for imaging and visualization in recent years. The development of machine vision devices at decreased costs, as well as their miniaturization and integration in industrial processes, have accelerated the use of 3D imaging systems in industry. In this paper we describe how to improve the performance of a 3D imaging system for inline dimensional quality inspection of long, flat-rolled metal products manufactured in rolling mills we designed and developed in previous works. Two dimensional characteristics of rolled products are measured by the system: width and flatness. The system is based on active triangulation using a single-line pattern projected onto the surface of the product under inspection for range image acquisition. Taking the system calibration into account the range images are transformed into a calibrated point cloud representing the 3D surface reconstruction of the product. Two approaches to improve the line detection and extraction method used in the original system are discussed, one intended for high-speed processing with lower accuracy, and the other providing high accuracy while incurring higher computational time expenses. A mechanism to remove, or at least reduce, the effects of product movements while manufacturing, such as bouncing and flapping, is also proposed to improve the performance of the system.     

Real-time recovery of moving 3D faces for emerging applications

Existing face imaging systems are not suitable to meet the face representation and recognition demands for emerging applications in areas such as interactive gaming, enhanced learning environments and directed advertising. This is mainly due to the poor capture and characterisation of facial data that compromises their spatial and temporal precision. For emerging applications it is not only necessary to have a high level of precision for the representation of facial data, but also to characterise dynamic faces as naturally as possible and in a timely manner. This study proposes a new framework for capturing and recovering dynamic facial information in real-time at significantly high order of spatial and temporal accuracy to capture and model subtle facial changes for enhanced realism in 3D face visualisation and higher precision for face recognition applications. We also present a novel, fast, and robust correspondence mapping approach for 3D registration of moving 3D faces.     

Robust 3D face capture using example-based photometric stereo

We show that using example-based photometric stereo, it is possible to achieve realistic reconstructions of the human face. The method can handle non-Lambertian reflectance and attached shadows after a simple calibration step. We use spherical harmonics to model and de-noise the illumination functions from images of a reference object with known shape, and a fast grid technique to invert those functions and recover the surface normal for each point of the target object. The depth coordinate is obtained by weighted multi-scale integration of these normals, using an integration weight mask obtained automatically from the images themselves. We have applied these techniques to improve the PhotoFace system of Hansen et al. (2010).     

Evaluation of linear spectral unmixing and ΔNBR for predicting post‐fire recovery in a North American ponderosa pine forest

The Differenced Normalized Burn Ratio (ΔNBR) is widely used to map post‐fire effects in North America from multispectral satellite imagery, but has not been rigorously validated across the great diversity in vegetation types. The importance of these maps to fire rehabilitation crews highlights the need for continued assessment of alternative remote sensing approaches. To meet this need, this study presents a first preliminary comparison of immediate post‐fire char (black ash) fraction, as measured by linear spectral unmixing, and ΔNBR, with two quantitative one‐year post‐fire field measures indicative of canopy and sub‐canopy conditions: % live tree and dry organic litter weight (gm^?2). Image analysis was applied to Landsat 7 Enhanced Thematic Mapper (ETM+) imagery acquired both before and immediately following the 2000 Jasper Fire, South Dakota. Post‐fire field analysis was conducted one‐year post‐fire. Although the immediate post‐fire char fraction (r ² = 0.56, SE = 28.03) and ΔNBR (r ² = 0.55, SE = 29.69) measures produced similarly good predictions of the % live tree, the standard error in the prediction of litter weight with the char fraction method (r ² = 0.55, SE = 4.78) was considerably lower than with ΔNBR (r ² = 0.52, SE = 8.01). Although further research is clearly warranted to evaluate more field measures, in more fires, and across more fire regimes, the char fraction may be a viable approach to predict longer‐term indicators of ecosystem recovery and may potentially act as a surrogate retrospective measure of the fire intensity.     

An integrated approach to land cover classification: An example in the Island of Jersey

A land cover map of Jersey was created using remotely sensed images recorded by satellite. This map brought together a range of disparate techniques, developed in isolation and mostly applied experimentally, integrating multisensor, multitemporal, enhanced spatial resolution data within an object-oriented integrated Geographical Information System (GIS) for an applications-driven, operational programme. It was developed under the Classification of Environment with Vector- and Raster-Mapping (CLEVER-Mapping) project: this improved approach to operational land cover mapping used information on the subdivision of the landscape into land parcels to help classify remotely sensed images on a per-parcel basis. The object-oriented approach allowed the use of remotely sensed information which relates directly to ground features, and the application of improved knowledge-based corrections using a range of external data. Unlike a conventional map, the parcel-based approach produced a GIS database containing classified land parcels which could also be used as a storage framework and analysis tool for other datasets in later analyses. The GIS recorded 21 land cover types. Validation against reference land parcel data gave a correspondence of between 85% and 95% depending on the level of class aggregation.     

The effect of tidal currents on radar backscatter from the sea around Portland Bill

Low grazing angle radar data of the sea surface were collected using three different frequencies (3, 10 and 16?GHz) from a cliff‐top site on the south coast of England. A number of features were observed in the radar imagery that could be related to the tidal current flow around Portland Bill. The strongest, most obvious features occurred near the time of low water, and these features had significantly reduced backscatter levels in horizontal polarization, with reductions up to 20?dB, or more, below the clutter levels around them. In vertical polarization, the reduction in the clutter level was typically somewhat smaller (10?dB or so) than the horizontally polarized backscatter. No convincing explanation of this effect has been found. The strain rate component in the radar line of sight was estimated from measurements of the current component calculated from the radar data. A comparison of range–time intensity images of the radar backscatter and the strain rate showed a number of strongly correlated features that repeated with the semi‐diurnal tidal period. The maximum strain rate was around 0.0005?s^?1, which produced modulations in the radar backscatter of around 2–3?dB. On occasions a number of bright streaks with a separation of around 100?m were also observed, moving away from the radar at a few cm?s^?1. A satellite image from European Remote Sensing Satellite (ERS)‐2 of the Portland area suggests that the slow‐moving streaks may be internal waves generated by tidal flow over raised bathymetry.     

High-Throughput Analysis of Algal Crude Oils Using High Resolution Mass Spectrometry

Lipid analysis often needs to be specifically optimized for each class of compounds due to its wide variety of chemical and physical properties. It becomes a serious bottleneck in the development of algae-based next generation biofuels when high-throughput analysis becomes essential for the optimization of various process conditions. We propose a high-resolution mass spectrometry-based high-throughput assay as a ‘quick-and-dirty’ protocol to monitor various lipid classes in algal crude oils. Atmospheric pressure chemical ionization was determined to be most effective for this purpose to cover a wide range of lipid classes. With an autosampler-LC pump set-up, we could analyze algal crude samples every one and half minutes, monitoring several lipid species such as TAG, DAG, squalene, sterols, and chlorophyll a. High-mass resolution and high-mass accuracy of the orbitrap mass analyzer provides confidence in the identification of these lipid compounds. MS/MS and MS3 analysis could be performed in parallel for further structural information, as demonstrated for TAG and DAG. This high-throughput method was successfully demonstrated for semi-quantitative analysis of algal oils after treatment with various nanoparticles.     

In-hospital smoking cessation programs: Who responds, who doesn't?

This study extends the results of a large randomized clinical trial of a multicomponent in-hospital smoking cessation intervention for general hospitalized smokers by examining subgroups of patients who responded to the intervention. The results, obtained using signal detection analysis, produced 6 subgroups of patients with varying degrees of intervention responsiveness. The subgroup most responsive was marked by 100% confidence to quit smoking at baseline. Among patients with less than 100% confidence, confidence interacted with age, depressed mood scores, addiction scores, and alcohol intake to discriminate 5 additional subgroups. Discussion focuses on how this information can be used in clinical decision making to treat subpopulations of smokers and directs attention to possible areas of underlying biopsychosocial processes that may interact to affect successful long-term cessation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)