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Asif Imran

Publications and source records attributed to Asif Imran.

21 records · Page 2Linked to original sources

Comparative Study of Statistical Skin Detection Algorithms for Sub-Continental Human Images

Object detection has been a focus of research in human-computer interaction. Skin area detection has been a key to different recognitions like face recognition, human motion detection, pornographic and nude image prediction, etc. Most of the research done in the fields of skin detection has been trained and tested on human images of African, Mongolian and Anglo-Saxon ethnic origins. Although there are several intensity invariant approaches to skin detection, the skin color of Indian sub-continentals have not been focused separately. The approach of this research is to make a comparative study between three image segmentation approaches using Indian sub-continental human images, to optimize the detection criteria, and to find some efficient parameters to detect the skin area from these images. The experiments observed that HSV color model based approach to Indian sub-continental skin detection is more suitable with considerable success rate of 91.1% true positives and 88.1% true negatives.

cs.CV↗

VERITAS Discovery of Variability in the VHE Gamma-Ray Emission of 1ES 1218+304

1ES 1218+304 is among a group of several TeV blazars that exhibit surprisingly hard energy spectra given their redshifts. The VERITAS collaboration has carried out an intensive observing campaign of 1ES 1218+304 in early 2009 to characterize the emission properties of one of these hard-spectra distant blazars in more detail. While hard-spectra TeV blazars are most promising for unveiling putative signatures from EBL absorption, they may also have implications on shock acceleration scenarios in relativistic jets. Our observations of 1ES 1218+304 demonstrate significant flux variability. Furthermore, we present an energy spectrum extending into the multi-TeV regime. The implications of these data for $γ$-ray emission models are discussed.

astro-ph.HE↗

Detecting a unique EBL signature with TeV gamma rays

We discuss prospects for detecting a spectral break in gamma-ray spectra of blazars due to the extragalactic background light (EBL) density falling off between the near and mid-IR. A measurable spectral change in the TeV spectra at 1 TeV could arise from a rapid or slow drop in the EBL density above ~1 micron. This effect is mediated by the ratio of the near to mid-IR density of EBL. A detection of such a spectral feature could become a clear signature of EBL absorption. A non-detection would give a strong observational constraint to the shape of the EBL spectrum. We present calculations estimating the sensitivity of TeV telescopes for detecting such a break for blazar observations at different redshifts.

astro-ph↗