Dense pixel matching between unrectified and distorted images using dynamic programming

In this paper, a novel framework for dense pixel matching based on dynamic programming is introduced. Unlike most techniques proposed in the literature, our approach assumes neither known camera geometry nor the availability of rectified images. Under such conditions, the matching task cannot be reduced to finding correspondences between a pair of scanlines. We propose to extend existing dynamic programming methodologies to a larger dimensional space by using a 3D scoring matrix so that correspondences between a line and a whole image can be calculated. After assessing our framework on a standard evaluation dataset of rectified stereo images, experiments are conducted on unrectified and non-linearly distorted images. Results validate our new approach and reveal the versatility of our algorithm.

DONUTS: A Science Frame Autoguiding Algorithm with Sub-Pixel Precision, Capable of Guiding on Defocused Stars

We present the DONUTS autoguiding algorithm, designed to fix stellar positions at the sub-pixel level for high-cadence time-series photometry, and also capable of autoguiding on defocused stars. DONUTS was designed to calculate guide corrections from a series of science images and recentre telescope pointing between each exposure. The algorithm has the unique ability of calculating guide corrections from undersampled to heavily defocused point spread functions. We present the case for why such an algorithm is important for high precision photometry and give our results from off and on-sky testing. We discuss the limitations of DONUTS and the facilities where it soon will be deployed.

Multi-standard sub-pixel interpolation architecture for video motion estimation

A new domain-specific reconfigurable sub-pixel interpolation architecture for multi-standard video Motion Estimation (ME) is presented. The mixed use of parallel and serial-input FIR filters achieves high throughput rate and efficient silicon utilisation. Flexibility has been achieved by using a multiplexed reconfigurable data-path controlled by a selection signal. Silicon design studies show that this can be implemented using 34.8K gates with area and performance that compares very favourably with existing fixed solutions based solely on the H.264 standard. ©2008 IEEE.

Children drawing their own conclusions: Children’s perceptions of a ‘post-conflict’ society

In societies emerging from conflict/war, sustained occurrence of violence appears to be a common feature. In Northern Ireland, while incidents of violent deaths and injuries specifically related to the political conflict have decreased dramatically since 1998, regular riots and paramilitary activity confirm continuing division and conflict. The study described here explored children’s perceptions of their own lives and their predecessors’ lives in the country, through a draw-and-tell technique (n=179). While multiple positive elements of peace/hope were depicted by the majority of children, especially in the pictures portraying the present, negative elements and violent references mostly appeared in the pictures representing the past. Violence was more likely to be portrayed by boys, older children, and those attending segregated education.

Characterisation of melt processed nanocomposites of Polyamide 6 subjected to uniaxial-drawing

In this paper, the processing and characterization of Polyamide 6 (PA6) nanocomposites containing graphite nanoplatelets (GNPs) is reported. PA6 nanocomposites were prepared by melt-mixing using an industrial, co-rotating, intermeshing, twin-screw extruder. A bespoke screw configuration was used that was designed in-house to enhance nanoparticle dispersion into a polymer matrix. The effects of nano-filler type (xGnPTM M-5 and xGnPTM C-500), nano-filler content, and extruder screw speed on the bulk properties of the PA6 nanocomposites were investigated. The crystalline structures of PA6 nanocomposites are related to thermal treatment, stress history and the presence of moisture and nanofillers. DSC, Raman and XRD studies show an increase in crystallinity with increasing GNP content and a phase transformation between α-form to γ-form crystals as a result of the heterophase nucleation effect. The effect of uniaxial stretching on PA6 nanocomposites was investigated by drawing specimens heated at temperatures below the melting temperature. DSC and Raman studies on the drawn samples show an increase in yield stress as the GNP content increases due to the strain induced crystallization and γ—β transition during stretching. The rheological response of the nanocomposites resemble that of a ‘pseudo-solid’, rather than a molten liquid, and analysis of the rheological data indicates that a percolation threshold was reached at GNP contents of between 10–15wt%. An increase in tensile modulus of as much as 412% was observed for PA6/C-500 xGnPTM composites, at a filler content of 20wt%. The enhancement of Young’s modulus and yield stress can be attributed to the reinforcing effect of GNPs and their uniform dispersion in the PA6 matrix. The electrical conductivity of the composite also increased with increasing GNP content, with an addition of 15wt% GNP resulting in a 6 order-of-magnitude increase in conductivity. The effects of uniaxial-drawing and the inclusion of multiple nano-filler varieties on the electrical and mechanical properties are currently under investigation.

A Steganalysis System Utilizing Temporal Pixel Correlation Of HEVC Video

High Efficiency Video Coding (HEVC) is the most recent video codec coming after currently most popular H.264/MPEG4 codecs and has promising compression capabilities. It is conjectured that it will be a substitute for current video compression standards. However, to the best knowledge of the authors, none of the current video steganalysis methods designed or tested with HEVC video. In this paper, pixel domain steganography applied on HEVC video is targeted for the first time. Also, its the first paper that employs accordion unfolding transformation, which merges temporal and spatial correlation, in pixel domain video steganalysis. With help of the transformation, temporal correlation is incorporated into the system. Its demonstrated for three different feature sets that integrating temporal dependency substantially increased the detection accuracy.

Architectural drawing for Beckman Hall

Architectural drawing of the site for the Arnold and Mabel Beckman Business and Technology Hall, Chapman University, Orange, California, ca. 1997.

Architectural drawing for the Hutton Sports Center, Chapman College, Orange, California

Architectural drawing for the Hutton Sports Center, 219 E. Sycamore St., Chapman College, Orange, California. The Harold Hutton Sports Center, completed in 1978, is named in honor of this former trustee, and made possible by a gift from his wife, Betty Hutton Williams.