34 research outputs found
Example-based image colorization using locality consistent sparse representation
âImage colorization aims to produce a natural looking color image from a given grayscale image, which remains a challenging problem. In this paper, we propose a novel examplebased image colorization method exploiting a new locality consistent sparse representation. Given a single reference color image, our method automatically colorizes the target grayscale image by sparse pursuit. For efficiency and robustness, our method operates at the superpixel level. We extract low-level intensity features, mid-level texture features and high-level semantic features for each superpixel, which are then concatenated to form its descriptor. The collection of feature vectors for all the superpixels from the reference image composes the dictionary. We formulate colorization of target superpixels as a dictionary-based sparse reconstruction problem. Inspired by the observation that superpixels with similar spatial location and/or feature representation are likely to match spatially close regions from the reference image, we further introduce a locality promoting regularization term into the energy formulation which substantially improves the matching consistency and subsequent colorization results. Target superpixels are colorized based on the chrominance information from the dominant reference superpixels. Finally, to further improve coherence while preserving sharpness, we develop a new edge-preserving filter for chrominance channels with the guidance from the target grayscale image. To the best of our knowledge, this is the first work on sparse pursuit image colorization from single reference images. Experimental results demonstrate that our colorization method outperforms state-ofthe-art methods, both visually and quantitatively using a user stud
Quantum asymmetric cryptography with symmetric keys
Based on quantum encryption, we present a new idea for quantum public-key
cryptography (QPKC) and construct a whole theoretical framework of a QPKC
system. We show that the quantum-mechanical nature renders it feasible and
reasonable to use symmetric keys in such a scheme, which is quite different
from that in conventional public-key cryptography. The security of our scheme
is analyzed and some features are discussed. Furthermore, the state-estimation
attack to a prior QPKC scheme is demonstrated.Comment: 8 pages, 1 figure, Revtex
Zika Virus Disrupts Phospho-TBK1 Localization and Mitosis in Human Neuroepithelial Stem Cells and Radial Glia
Graphical Abstract Highlights d Derivation of human neocortical and spinal cord neuroepithelial stem (NES) cells d Zika virus (ZIKV) infects NES cells and radial glia, impairing mitosis and survival d ZIKV induces mitochondrial sequestration of centrosomal phospho-TBK1 d Nucleoside analogs inhibit ZIKV replication, protecting NES cells from cell death In Brief Onorati et al. establish neuroepithelial stem (NES) cells as a model for studying human neurodevelopment and ZIKV-induced microcephaly. Together with analyses in human brain slices and microcephalic human fetal tissue, they find that ZIKV predominantly infects NES and radial glial cells, reveal a pivotal role for pTBK1, and find that nucleoside analogs inhibit ZIKV replication, protecting NES cells from cell death
Effects of Different Iron Sources on the Growth and Iron Concentrations of Tissues, Organs, and Blood of Genetically Improved Farmed Tilapia (Oreochromis niloticus)
A 70-day feeding trial was conducted to elucidate the effects of different iron (Fe) sources on growth and Fe concentrations in the tissues, organs, and blood of genetically improved farmed tilapia (Oreochromis niloticus). Five experimental diets (45.0% crude protein, 3.7% crude lipid) with the same Fe concentration (100 mg/kg of feed) were formulated from different Fe sources: ferrous sulfate (FeSO4), ferric chloride (FeCl3), ferrous chloride (FeCl2), ferrous citrate (C6H5FeO7), and iron porphyrin (Fe-porphyrin). The results showed that the percent weight gain (%WG) of fish in the FeCl2 group was the greatest among all five groups (p mid-hind intestine > liver > gill, muscle, foregut > spine. The spleen had the highest Fe content in all groups on day 70. These results suggest that FeCl2 is the best source of dietary Fe for O. niloticus with %WG as the main indicator
Evaluation of IAQ Perception of Shopping Malls in Hong Kong
This study, sponsored by the Business Environment Council Limited, examined the publicâs perceptions of indoor air quality (IAQ) in shopping malls in Hong Kong. By surveying shoppers at ten malls, we found IAQ certifications and mall locations within Hong Kong do not correlate when it comes to perceptions of IAQ. We hypothesized that population density and configuration of the mall may be the issue. Also we proposed an IAQ management plan that would educate the shoppers and help mall managers