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1.
Joint photographic experts group (JPEG) can provide good quality with small file size but also eliminate extensively the redundancies of images. Therefore, hiding data into JPEG images in terms of maintaining high visual quality at small file sizes has been a great challenge for researchers. In this paper, an adaptive reversible data hiding method for JPEG images containing multiple two-dimensional (2D) histograms is proposed. Adaptability is mainly reflected in three aspects. The first one is to preferentially select sharper histograms for data embedding after histograms are established by constructing the th () histogram using the th non-zero alternating current (AC) coefficient of all the quantized discrete cosine transform blocks. On the other hand, to fully exploit the strong correlation between coefficients of one histogram, the smoothness of each coefficient is estimated by a block smoothness estimator so that a sharply-distributed 2D-histogram is constructed by combining two coefficients with similar smoothness into a pair. The pair corresponding to low complexity is selected priorly for data embedding, leading to high embedding performance while maintaining low file size. Besides, we design multiple embedding strategies to adaptively select the embedding strategy for each 2D histogram. Experimental results demonstrate that the proposed method can achieve higher rate–distortion performance which maintaining lower file storage space, compared with previous studies. 相似文献
2.
Knowledge distillation has become a key technique for making smart and light-weight networks through model compression and transfer learning. Unlike previous methods that applied knowledge distillation to the classification task, we propose to exploit the decomposition-and-replacement based distillation scheme for depth estimation from a single RGB color image. To do this, Laplacian pyramid-based knowledge distillation is firstly presented in this paper. The key idea of the proposed method is to transfer the rich knowledge of the scene depth, which is well encoded through the teacher network, to the student network in a structured way by decomposing it into the global context and local details. This is fairly desirable for the student network to restore the depth layout more accurately with limited resources. Moreover, we also propose a new guidance concept for knowledge distillation, so-called ReplaceBlock, which replaces blocks randomly selected in the decoded feature of the student network with those of the teacher network. Our ReplaceBlock gives a smoothing effect in learning the feature distribution of the teacher network by considering the spatial contiguity in the feature space. This process is also helpful to clearly restore the depth layout without the significant computational cost. Based on various experimental results on benchmark datasets, the effectiveness of our distillation scheme for monocular depth estimation is demonstrated in details. The code and model are publicly available at : https://github.com/tjqansthd/Lap_Rep_KD_Depth. 相似文献
3.
Yarn-dyed fabric is often woven from warp and weft yarns in the same color depth to ensure a uniform color appearance. The difference in color depth between warp and weft tends to result in the uneven color of the yarn-dyed fabric. This article aims to establish a color tolerance for yarn-dyed fabric that can be woven with a qualified color appearance but from the warp and weft yarns in different color depths. A total of 27 yarn-dyed fabric samples in three color series (red, yellow, and blue) were evaluated by using the yarn-dyed fabric from warp and weft yarns in the same color depth of 2% (on weight of fabric, owf) as the standard. Visual assessment and instrumental measurement of color were carried out to establish the color tolerance ellipse that was defined as CMC (Color Measurement Committee) color differences (2:1) of no more than 1.00. It was found that the color strengths (K/S) and color differences (ΔECMC(2:1)) of these fabric samples for each color series had linear relationships with the color depths of warp and weft yarns. The color tolerance ellipses indicated that, even though the warp and weft yarns had an apparent color difference, they could be woven in fabrics with relatively uniform color appearance and meet the requirements for yarn-dyed fabric. This work provided valuable insight into the production of qualified yarn-dyed fabrics from unqualified dyed yarns. 相似文献
4.
《Ceramics International》2022,48(16):23072-23080
The present study correlates the effect of R-cation radii on structural, vibrational, optical, and dielectric properties of rhombohedral rare earth aluminates RAlO3 (R = La, Pr, Nd). The polycrystalline samples of RAlO3 have been synthesized using sol-gel synthesis technique. Pure rhombohedral phase of RAlO3 samples has been confirmed with X-ray diffraction. Systematic decrements in the lattice parameter, bond length, and bond angle have been observed, giving rise to structural distortion due to decrease in ionic radii of R-cation. The phononic properties of RAlO3 have been investigated through Raman spectroscopy, where the degree of distortion of AlO6 octahedra can be analyzed with the peak position of Eg and A1g modes. An increase in the energy bandgap with decreasing R-cation radii shows an interconnection with the decrease in Al–O bond length. Interestingly, the decreasing dielectric constant with decreasing ionic radii of R-cation has been correlated with the difference in electronegativity of cation(R3+)-anion(O2?) pair. Also, a positive linear relationship between dielectric constant and energy bandgap has been investigated using Penn model. 相似文献
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针对利用深度学习方法对街道图像进行深度估计,提出采用语义分割的方法解决深度图出现边界模糊等问题;估计深度通过左右视角图生成视差图进行无监督的训练。在网络模型中添加语义分割层,采取多个空洞卷积并行的结构增加感受野,同时减少了图像下采样的次数,降低了由于下采样带来的信息损失,使得的结果更加准确。这也是在深度估计中首次与空洞卷积相结合增加准确率。通过对KITTI街道数据集进行训练,与现有结果相比,除了增加检测准确性,降低错误率之外,使得效果图中的物体更加清晰,并且在效果图中还保留了一些原模型中被忽视掉的细节信息,将原始图像更加完整的表现出来。 相似文献
8.
针对在传统的客户流失预测数据预处理中,使用one-hot编码处理离散属性导致数据维度增加及数据过于稀疏的问题,提出了两种基于多层感知机的改进后的客户流失预测模型。其主要思想是分别使用堆叠自编码器和实体嵌入两种方法对多层感知机进行改进,通过将离散属性的高维编码数据向低维空间映射,有效地减少了one-hot编码产生的稀疏数据,增加了离散属性值之间的关联度。在对两份公开的数据集进行交叉验证后的实验结果表明,改进后的模型既有效地提高了预测的准确度,又维持了传统多层感知机模型在并行化计算方面的优势。 相似文献
9.
利用Gleeble-3500热模拟试验机研究了低活化马氏体钢在变形温度为850~950 ℃、应变速率为0.001~1 s-1条件下的热变形行为。建立了流变应力本构方程,并评估了该方程的预测能力。绘制了低活化马氏体钢在不同应变下的热加工图。结果表明:在较高的应变速率条件下,该材料主要发生动态回复,在较高变形温度和较低应变速率下具有明显的动态再结晶特征;本构方程的预测结果与实验结果符合良好;变形温度870~930 ℃、应变速率0.001~0.01 s-1和变形温度920~950 ℃、应变速率0.3~1 s-1分别是真应变为0.4和0.6下最优的热加工区域。 相似文献
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