264 research outputs found
Dual Associated Encoder for Face Restoration
Restoring facial details from low-quality (LQ) images has remained a
challenging problem due to its ill-posedness induced by various degradations in
the wild. The existing codebook prior mitigates the ill-posedness by leveraging
an autoencoder and learned codebook of high-quality (HQ) features, achieving
remarkable quality. However, existing approaches in this paradigm frequently
depend on a single encoder pre-trained on HQ data for restoring HQ images,
disregarding the domain gap between LQ and HQ images. As a result, the encoding
of LQ inputs may be insufficient, resulting in suboptimal performance. To
tackle this problem, we propose a novel dual-branch framework named DAEFR. Our
method introduces an auxiliary LQ branch that extracts crucial information from
the LQ inputs. Additionally, we incorporate association training to promote
effective synergy between the two branches, enhancing code prediction and
output quality. We evaluate the effectiveness of DAEFR on both synthetic and
real-world datasets, demonstrating its superior performance in restoring facial
details.Comment: Technical Repor
Catalogue of topological electrons and phonons in all allotropes of carbon
Carbon, as one of the most common element in the earth, constructs hundreds
of allotropic phases to present rich physical nature. In this work, by
combining the ab inito calculations and symmetry analyses method, we
systematically study a large number of allotropes of carbon (703), and
discovered 315 ideal topological phononic materials and 32 topological
electronic materials. The ideal topological phononic nature includes single,
charge-two, three, four Weyl honons, the Dirac or Weyl nodal lines phonons, and
nodal surfaces phonons. And the topological electron nature ncludes topological
insulator, (Type-II) Dirac points, triple nodal points, the Dirac (Weyl) nodal
lines, quadratic nodal lines and so on. For convenience, we take the uni in SG
178 and pbg in SG 230 as the examples to describe the topological features in
the main. We find that it is the coexistence of single pair Weyl phonons and
one-nodal surfaces phonons in the uni in SG 178, which can form the single
surface arc in the (100) surface BZ and isolated double-helix surface states
(IDHSSs)in the (110) surface BZ. In topological semimetal pbg in SG 230, we
find that the perfect triple degenerate nodal point can be found in the near
Fermi level, and it can form the clear surface states in the (001) and (110)
surface BZ. Our work not only greatly expands the topological features in all
allotropes of carbon, but also provide many ideal platforms to study the
topological electrons and phonons
Direct fiber vector eigenmode multiplexing transmission seeded by integrated optical vortex emitters
Spatial modes have received substantial attention over the last decades and are used in optical communication applications. In fiber-optic communications, the employed linearly polarized modes and phase vortex modes carrying orbital angular momentum can be synthesized by fiber vector eigenmodes. To improve the transmission capacity and miniaturize the communication system, straightforward fiber vector eigenmode multiplexing and generation of fiber-eigenmode-like polarization vortices (vector vortex modes) using photonic integrated devices are of substantial interest. Here, we propose and demonstrate direct fiber vector eigenmode multiplexing transmission seeded by integrated optical vortex emitters. By exploiting vector vortex modes (radially and azimuthally polarized beams) generated from silicon microring resonators etched with angular gratings, we report data-carrying fiber vector eigenmode multiplexing transmission through a 2-km large-core fiber, showing low-level mode crosstalk and favorable link performance. These demonstrations may open up added capacity scaling opportunities by directly accessing multiple vector eigenmodes in the fiber and provide compact solutions to replace bulky diffractive optical elements for generating various optical vector beams
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