We analyze the star formation activity of an homogeneous LSB dwarf galaxy sample in the Virgo cluster, as a function of the radial velocity relative to the cluster mean velocity and the projected distance from the center of the cluster, using CCD images obtained at the Wise Observatory. The localized Hα emission in the HII regions of this sample is compared to that of an isolated gas-rich sampl...

Using Monte Carlo radiative transfer techniques, we model the dust content of the edge-on low surface brightness (LSB) galaxy UGC 7321 and explore the effects of dust on its disk color gradients. Dust alone cannot explain the large radial disk color gradients observed in this galaxy and we find that a significant fraction (∼50%) of the dust in UGC 7321 appears to be contained in a clumped mediu...

JSteg is a steganographic method for JPEG images that can be viewed as LSB steganography. Recently, we proposed a new principle to detect the use of LSB steganography in digitized vector signals and showed how to apply it to gray-scale images. In this paper, we discuss how to apply it to JPEG images and show some experimental results for the JSteg-like algorithm. Introduction: JSteg-like algori...

Recent observations have revealed a population of blue galaxies at intermediate redshift with a space density well in excess of expectations from the local luminosity function and standard cosmology. The colors and luminosities of these faint blue galaxies are similar to nearby low surface-brightness (LSB) galaxies. Such galaxies are severely underrepresented in surveys used to de ne the local ...

In this paper, a 9-bit 1GS/s high precision folding A/D converter with a 45 nm CMOS technology is proposed. In order to improve the asymmetrical boundary condition error of a conventional folding ADC, a novel scheme with an odd number of folding blocks is proposed. Further, a new digital encoding technique is described to implement the odd number of folding technique. The proposed ADC employs a...

Ground-based & HST images of the nearby galaxy SBS 1543+593 (z = 0.009) show it to be a Low Surface Brightness (LSB) galaxy with a central surface brightness of μB(0) = 23.2 mag arcsec−2 and scale length 0.9 h−1 kpc, values typical for the local LSB galaxy population. The galaxy lies directly in front of the QSO HS 1543+5921 (z = 0.807); an HST STIS spectrum of the quasar reveals a damped Lyα (...

Steganography is derived from the Greek word steganos which literally means “Covered” and graphy means “Writing”, i.e. covered writing. Steganography is the art and science of hiding messages in such a way that no one apart from sender and receiver identify the message. The paper describes the steganalysis technique for the detection of secret message in the image. The strong and weak point of ...

In this paper we present an LSB steganalysis technique that can detect the existence of hidden messages that are randomly embedded in the least significant bits of natural continuous-tone images. The technique is inspired by recent work of Fridrich et al. [1] and just like [1], it can also precisely measure the length of the embedded message, even when the hidden message is very short relative ...

We have analyzed deep Near Infrared (NIR) broad band images for a sample of Blue Compact Dwarf Galaxies (BCDs), observed with the ESO NTT and Calar Alto 3.6m telescopes. The data presented here allows for the detection and quantitative study of the extended stellar low-surface brightness (LSB) host galaxy in all sample BCDs. NIR surface brightness profiles (SBPs) of the LSB host galaxies agree ...

A new HI catalog of Low Surface Brightness galaxies out to z=0.1 Abstract. Using both the Arecibo 305m and the Nançay decimetric 100-m class radio telescopes, we have observed the H i line of 116 Low Surface Brightness (LSB) galaxies from the Bothun et al. 1985 subset of LSB galaxies in the Uppsala General Catalog. The observations had a detection rate of 70%, resulting in the new determination...