共查询到20条相似文献,搜索用时 62 毫秒
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引言水下全息测绘是一项涉及水下全息图记录的技术,之后在实验室环境内再现全息实像,以获得精确的位置和尺寸信息。全息图的高分辨率和三维特性,包括图内的视差与透视,使我们可以在实验室光学系统中重新建立水下景像。实像处于底片前的空间内,这意味着该实像可以用屏... 相似文献
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分析了全息光栅在光学读出头中的作用。给出了用于光头中的全息光栅的设计原理,推出了记录和再现公式,并计算在共轭参考光再现全息光栅时再现实像的象差。 相似文献
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数字像面全息显微技术中,记录过程引入的噪声限制了轴向测量的精度和可靠性。目前对于抑噪方法的研究,主要针对高频噪声。因此提出了一种针对数字像面全息显微技术的降噪方法,不仅抑制高频噪声,对噪声的低频部分也有抑制作用,提高重构相位的信噪比。这种降噪方法对数字像面全息显微图进行优化,实现途径为利用二维经验模态分解中,第一层本征模态函数与全息图干涉条纹灰度信息契合的特点,提取第一层本征模态函数实现优化。应用优化后的像面全息图,实现重构,求解相位,测量样本表面形貌。应用优化方法对标准纳米台阶的表面形貌进行测量,对比并分析优化前后全息图的频谱以及测量的高度图,证明优化方法在保证对微结构表面形貌实现可靠测量的基础上,降低了数字像面全息显微技术的重构相位噪声。 相似文献
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本文分析了利用透镜成像的像面强度全息图的衍射特性,提出了利用双缝孔径记录像面强度彩虹全息图的方法,同时给出了实验结果。 相似文献
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本文提出利用光栅产生类似多狭缝形式的带状谱获得消色像的全息记录方法,讨论了获得消色像的条件,并给出了实验结果。 相似文献
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Due to the absorption and scattering effects of the water, underwater images tend to suffer from many severe problems, such as low contrast, grayed out colors and blurring content. To improve the visual quality of underwater images, we proposed a novel enhancement model, which is a trainable end-to-end neural model. Two parts constitute the overall model. The first one is a non-parameter layer for the preliminary color correction, then the second part is consisted of parametric layers for a self-adaptive refinement, namely the channel-wise linear shift. For better details, contrast and colorfulness, this enhancement network is jointly optimized by the pixel-level and characteristic-level training criteria. Through extensive experiments on natural underwater scenes, we show that the proposed method can get high quality enhancement results. 相似文献
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Object detection is an important process in image processing, it aims to detect instances of semantic objects of a certain class in digital images and videos. Object detection has applications in many areas of computer vision such as underwater fish detection. In this paper we present a method for preprocessing and fish localization in underwater images. We are based on a Poisson–Gauss theory, because it can accurately describe the noise present in a large variety of imaging systems. In the preprocessing step we denoise and restore the raw images. These images are split into regions utilizing the mean shift algorithm. For each region, statistical estimation is done independently in order to combine regions into objects. The method is tested under different underwater conditions. Experimental results show that the proposed approach outperforms state of the art methods. 相似文献
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数字图像处理在激光全息中的应用 总被引:1,自引:1,他引:1
本文主要介绍了利用计算机生成的数字图像代替传统的三维立体模型作为全息拍摄对象的方法。从数字图像的全息记录原理出发,讨论了数字图像的分辨率及设计方法问题。 相似文献
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随着近几年对光学全息术的进一步探索和研究,发现其在人工神经网络、高密度存储、光镊、信息编码译码和光束扭曲打结等方面有着广泛的应用,本文对全息术的原理及在现代光学中的应用做了简要介绍。 相似文献
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With increasing attentions being drawn to the underwater observation and utilization of marine resources in recent years, underwater image processing and analysis have become an active research hotspot. Different from the general images, marine environment is usually faced with some complicated situations such as underwater turbulence and diffusion, severe absorption and scattering of water body, various noises, low contrast, uniform illumination, monotonous color, complex underwater-background. In response to these typical challenges, a large body of works in underwater image processing has been exploited in recent years. This survey introduces a review of existing relatively mature and representative underwater image processing models, which are classified into seven categories including enhancement, fog removal, noise reduction, segmentation, salient object detection, color constancy and restoration. We then objectively evaluate the current situations and future development trend of underwater image processing, and provide some insights into the prospective research directions to promote the development of underwater vision and beyond. 相似文献