Hand and face segmentation using motion and colour cues in digital image sequences

© 2001 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.In this paper, we present a hand and face segmentation algorithm using motion and color cues. The algorithm is proposed for the content based representation of sign language image sequences, where the hands and face constitute a video object. Our hand and face segmentation algorithm consists of three stages, namely color segmentation, temporal segmentation, and video object plane generation. In color segmentation, we model the skin color as a normal distribution and classify each pixel as skin or non-skin based on its Mahalanobis distance. The aim of temporal segmentation is to localize moving objects in image sequences. A statistical variance test is employed to detect object motion between two consecutive images. Finally, the results from color and temporal segmentation are analyzed to yield a change detection mask. The performance of the algorithm is illustrated by simulation carried out on the silent test sequence.Nariman Habili ; Cheng-Chew Lim ; Alireza Moin

Segmentation of the face and hands in sign language video sequences using color and motion cues

Copyright © 2004 IEEEWe present a hand and face segmentation methodology using color and motion cues for the content-based representation of sign language video sequences. The methodology consists of three stages: skin-color segmentation; change detection; face and hand segmentation mask generation. In skin-color segmentation, a universal color-model is derived and image pixels are classified as skin or nonskin based on their Mahalanobis distance. We derive a segmentation threshold for the classifier. The aim of change detection is to localize moving objects in a video sequences. The change detection technique is based on the F test and block-based motion estimation. Finally, the results from skin-color segmentation and change detection are analyzed to segment the face and hands. The performance of the algorithm is illustrated by simulations carried out on standard test sequences.Nariman Habili, Cheng Chew Lim, and Alireza Moin

Characterization of grapevine leafroll-associated virus 3 genetic variants and application towards RT-qPCR assay design

Grapevine leafroll-associated virus 3 (GLRaV-3) is the most widely prevalent and economically important of the complex of RNA viruses associated with grapevine leafroll disease (GLD). Phylogenetic studies have grouped GLRaV-3 isolates into nine different monophyletic groups and four supergroups, making GLRaV-3 a genetically highly diverse virus species. In addition, new divergent variants have been discovered recently around the world. Accurate identification of the virus is an essential component in the management and control of GLRaV-3; however, the diversity of GLRaV-3, coupled with the limited sequence information, have complicated the development of a reliable detection assay. In this study, GLRaV-3 sequence data available in GenBank and those generated at Foundation Plant Services, University of California-Davis, was used to develop a new RT-qPCR assay with the capacity to detect all known GLRaV-3 variants. The new assay, referred to as FPST, was challenged against samples that included plants infected with different GLRaV-3 variants and originating from 46 countries. The FPST assay detected all known GLRaV-3 variants, including the highly divergent variants, by amplifying a small highly conserved region in the 3' untranslated terminal region (UTR) of the virus genome. The reliability of the new RT-qPCR assay was confirmed by an enzyme linked immunosorbent assay (ELISA) that can detect all known GLRaV-3 variants characterized to date. Additionally, three new GLRaV-3 divergent variants, represented by four isolates, were identified using a hierarchical testing process involving the FPST assay, GLRaV-3 variant-specific assays and high-throughput sequencing analysis. These variants were distantly related to groups I, II, III, V, VI, VII and IX, but much similar to GLRaV-3 variants with no assigned group; thus, they may represent new clades. Finally, based on the phylogenetic analysis, a new GLRaV-3 subclade is proposed and named as group X.Alfredo Diaz-Lara, Vicki Klaassen, Kristian Stevens, Mysore R. Sudarshana, Adib Rowhani ... Nuredin Habili ... et al

Australian Shiraz Disease: an emerging virus disease of Vitis vinifera cv. Shiraz

Nuredin Habil

The recent importation of Grapevine Pinot gris virus into Australia

Published online: 13 June 2017A total of 575 commercial grapevine (Vitis vinifera) samples from Australia have been tested for a newly emerging virus, Grapevine Pinot gris virus (Trichovirus, Betaflexiviridae) during 2015-2017. Nine samples from two states tested positive. Six of these were from New South Wales and 3 from South Australia in a total of eight varieties. All these varieties were imported from Europe within the last 4-19 years. A fragment of 431 nucleotides on the coat protein gene of Grapevine Pinot gris virus was targeted for virus identification by RT-PCR. The virus specificity of each positive sample was confirmed by sequencing followed by the BLASTn analysis which showed an identity of up to 99.3% to the virus sequences in the NCBI database. The phylogenetic tree as well as pairwise sequence identity showed that, although the virus sequence in each variety was unique, they all grouped with the isolates from Europe and well away from the South Korean and several Chinese isolates. This is the first report of the occurrence of Grapevine Pinot gris virus in Australia.Qi Wu, Nuredin Habil

Developing a standardised sampling protocol for consistent detection of grapevine viruses by the PCR assay

Nuredin Habili, Jonh W. Randle

Two viruses detected in table grapes imported into Australia from California

© Australasian Plant Pathology Society 2008Bunches of two table grape varieties, white Thompson Seedless and black Gem Seedless, imported from California were tested for 12 viruses, for phytoplasmas and for Xylella fastidiosa, the causal agent of Pierce’s disease. Reverse transcription–polymerase chain reaction (RT-PCR) of the extracts of pedicels and berry skin revealed the presence of one virus, Rupestris stem pitting associated virus (RSPaV) in Thompson Seedless, while in Gem Seedless both RSPaV and Grapevine leafroll-associated virus 4 were detected. This is the first report of the use of bunches for monitoring the movement of intracellular pathogens across quarantine borders.N. Habili and J. W. Randle

Sudden increase in the onset of grapevine yellow speckle disease in 2010

Nuredin Habili and John Randleshttp://proxy.library.adelaide.edu.au/login?url=http://search.ebscohost.com/login.aspx?direct=true&db=anh&AN=53304880&site=ehost-live&scope=sit

Grapevine leafroll-associated virus 1 as a common grapevine pathogen

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