Colorization is a computer-assisted process for adding colors to grayscale images or movies. It can be viewed as a process for assigning a three-dimensional color vector (YUV or RGB) to each pixel of a grayscale image. In previous works, with some color hints the resultant chrominance value varies linearly with that of the luminance. However, it is easy to find that existing methods may introduce obvious color bleeding, especially, around region boundaries. It then needs extra human-assistance to fix these artifacts, which limits its practicability. Facing such a challenging issue, we introduce a general and fast colorization methodology with the aid of an adaptive edge detection scheme. By extracting reliable edge information, the proposed approach may prevent the colorization process from bleeding over object boundaries. Next, integration of the proposed fast colorization scheme to a scribblebased colorization system, a modified color transferring system and a novel chrominance coding approach are investigated. In our experiments, each system exhibits obvious improvement as compared to those corresponding previous works.

Crystalline thin films of SiCN have been grown by microwave plasma-enhanced chemical vapor deposition using H2, CH4, N2, and SiH4 gases. The ternary compound (C;Si)xNy exhibits a hexagonal structure and consists of a network wherein the Si and C are substitutional elements. While the N content of the compound is about 35–40 at. %, the extent of Si substitution varies and can be as low as 10 at. %. Optical properties of the SiCN compounds have been studied by photoluminescence (PL), piezoreflectance (PzR), and photothermal deflection (PDS) spectroscopies. From the PzR measurement, we determine the direct band gap of the new crystals to be around 3.8 eV at room temperature. PDS measurement shows two absorption features with the first peak at around 3.2 eV which is related to an indirect band gap. The second PDS peak occurred around 3.8 eV and is quite consistent with the direct band gap determined by PzR. From the PL measurement, it is also found that the SiCN compounds have a near band edge emission centered around 3.26 eV at room temperature, which is consistent with the fundamental band gap obtained from the PDS measurement. These optical results indicate the potential of SiCN for blue and uv optoelectronic applications.

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the dimensionless figure of merit zT = PF•T/κ = α 2 σT/(κ e + κ L ), where α, σ, T, κ e , and κ L are the Seebeck coefficient, electrical conductivity, absolute temperature, and electronic and lattice contributions to the total thermal conductivity, respectively. [3] PF denotes the TE power factor that characterizes electrical transport performance. In practice, the average power factor (PF avg ) is directly proportional to the output power density of TE devices. [4] Therefore, for practical application, a higher PF avg is more desirable for achieving a large output power. In principle, PF and PF avg are both determined by electronic band structure and optimal carrier concentration. [5][6][7] Several strategies have been proposed to enhance both PF and PF avg . For example, Pei et al. [8] showed that a high peak PF can be achieved in PbTe by increasing the band degeneracy; Zhu et al. [9] demonstrated that FeNb 1−x Ti x Sb reaches high PF via reducing band effective mass, which results in high carrier mobility. In recent years, it has been elucidated that grain boundaries also play an important role in carrier scattering for certain TE compounds. For instance, Zhao et al. [10,11] revealed that both p and n-type SnSe single crystals that are free of grain boundaries exhibit high PFs; Snyder et al. [12,13] discovered that PF of Mg 3 Sb 2 -based Thermoelectric materials are typically highly degenerate semiconductors, which require high carrier concentration. However, the efficiency of conventional doping by replacing host atoms with alien ones is restricted by solubility limit, and, more unfavorably, such a doping method is likely to cause strong charge-carrier scattering at ambient temperature, leading to deteriorated electrical performance. Here, an unconventional doping strategy is proposed, where a small trace of alien atoms is used to stabilize cation vacancies in Cu 3 SbSe 4 by compositing with CuAlSe 2 , in which the cation vacancies rather than the alien atoms provide a high density of holes. Consequently, the hole concentration enlarges by six times but the carrier mobility is well maintained. As a result, a record-high average power factor of 19 µW cm −1 K −2 in the temperature range of 300-723 K is attained. Finally, with further reduced lattice thermal conductivity, a peak zT value of 1.4 and a record-high average zT value of 0.72 are achieved within the diamond-like compounds. This new doping strategy not only can be applied for boosting the average power factor for thermoelectrics, but more generally can be used to maintain carrier mobility for a variety of semiconductors that need high carrier concentration.

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