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一种有效的红外小目标检测方法 总被引:1,自引:1,他引:0
提出了一种基于中值滤波与梯度法的红外小目标检测方法.该方法首先通过中值滤波对红外图像进行平滑处理,接着采用背景差分技术将原始图像与经过中值滤波后的图像进行差分对消.在此基础上,再使用梯度锐化法对残差图像进行边缘信息的增强.最后,利用二值化处理凸显出目标点.该方法通过中值滤波与梯度法的互补效应实现了红外小目标的有效检测,仿真实验结果证明了该算法的有效性. 相似文献
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基于图像灰度梯度最大值累加的自动调焦算法 总被引:3,自引:0,他引:3
从光学系统出发介绍了基于图像处理的离焦图像成像原理,分析了传统基于灰度梯度的自动调焦算法的缺陷——灰度梯度考虑不全面并且易受噪音影响.针对传统算法不足,提出了基于图像灰度梯度最大值累加的自动调焦算法.该算法通过计算中心像素的八邻域灰度梯度,以自动聚焦区域内各像素最大灰度梯度与最大灰度与最小梯度差值乘积之和作为新的评价函数,分析了该算法可以抑制噪音影响的原理;介绍了焦点搜索自适应变步长爬山算法原理和实现过程;最后进行算法性能实验验证.首先,利用不同算法对序列图像和加入高斯噪音的图像进行清晰度评价,结果证明该算法对含噪图像的清晰度评价准确,与传统算法相比该算法在抑制噪音方面具有优越性;其次,用不同聚焦算法进行序列图像自动调焦实验,结果显示传统算法会出现错误聚焦的情况,而该算法聚焦准确迅速,相比于传统算法具有明显优势. 相似文献
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显微数字全息数值再现中的自动聚焦 总被引:1,自引:0,他引:1
自动聚焦是显微数字全息数值再现中的一项关键技术。基于菲涅耳变换重建算法, 采用实验验证的方法, 对显微数字全息成像中六种典型聚焦评价函数的性能进行了对比研究。提出了利用再现像部分区域进行调焦判断的方法。结果表明, 这些函数都具有较好的单峰性、一致的调焦范围和准确性, 但与梯度运算相关的调焦函数运算时间太长; 傅里叶频谱函数调焦速度最快, 是首选的聚焦评价函数。选取再现像部分区域作为调焦计算区域, 可大大缩短调焦时间。对于低信噪比全息图, 利用维纳自适应滤波进行预处理及对再现像进行后处理, 有利于提高自动调焦的准确性及再现像的质量。 相似文献
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《光学学报》2017,(6)
在红外对空探测系统中,由于探测器时刻处于运动状态使得目标图像产生剧烈的运动模糊,给红外小目标检测造成困难。为了解决运动模糊条件下红外小目标检测的问题,提出将运动模糊复原技术和图像增强技术引入红外探测系统。先将探测器采集到的原始图像经过维纳滤波,对运动模糊进行处理并抑制噪声干扰,再利用梯度法对处理后的图像做锐化处理,增强目标边缘。实验验证和仿真分析结果都表明,该方法运动模糊复原效果明显,并在一定程度上抑制了噪声,提高了目标对比度,使目标在背景中更加凸显,并且能够显著提高目标图像质量。引入的评价参数峰值信噪比和均方差表现良好,该方法可以增强探测系统的使用性能。 相似文献
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提出一种多算法融合的图像增强方法,用于工程应用中的复杂降质图像的细节特征恢复.该方法汲取了Laplacian变换法、Sobel梯度法、盒状滤波法、非锐化掩蔽法及灰度幂律法等算法的优点,可对模糊图像进行自适应增强.通过拉普拉斯滤波器和梯度滤波器将原始图像分为基础层、细节层及边缘特征层;对微小细节信息及边缘特征信息进行增强,对基础信息进行压缩;然后采用盒装滤波器对图像的三个分层进行平滑过度及噪音过滤,最后使用非锐化掩蔽法和灰度变换来增加图像灰度的动态范围,从而得到增强后的图像.在相同的工况下,该方法分别与直方图均衡法、自适应伽马矫正法及小波变换的图像增强法实验结果进行对比,结果表明,该方法将图像的清晰度提高了13.1%~126.1%,能有效地处理复杂型感染的图像,避免图像过度增强,可以获得适合人眼的最佳视觉细节内容的增强效果. 相似文献
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自动调焦系统中一种调焦的判别方法 总被引:1,自引:0,他引:1
准确有效的调焦评价函数是采用数字图像处理技术实现自动调焦的关键环节,而调焦评价函数的好坏又直接影响着调焦系统的结构精度和运算的复杂程度。分析了灰度标准差比较法和灰度对比度比较法的优缺点,提出了经改进的灰度比较法作为调焦评价函数,该方法具有响应速度快、计算量小、信噪比高、可靠性好等特点。实验与分析结果表明,该方法对具有复杂细节和纹理特征的图像能得到较好的处理结果,而对于背景高亮度的图像则不能判断其是否聚焦。 相似文献
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一种具有噪声抑制功能的红外图像锐化算法 总被引:1,自引:0,他引:1
锐化是图像增强中一项关键性的技术,但如果图像中包含噪声,噪声也会因为锐化而放大,最终导致信噪比的降低.探索了一种算法既可以对图像进行锐化滤波,又不降低图像的信噪比.采用模式识别的相关理论,基于隶属度和概率松弛技术对红外图像中由真实边缘和由各种噪声引起的亮度数值变化进行区分,对不同区域采用不同的锐化处理.该算法不同于传统图像锐化算法只基于局部对比度的缺点,在图像锐化过程中考虑图像边缘和噪声的空间分布的差异,改善了传统边缘增强算法对噪声放大的缺点.实验数据表明,该锐化方法未引起信噪比的降低,具有良好的前景和实用价值. 相似文献
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Fei Yu Mei Hui Wei Han Peng Wang Li-quan Dong Yue-jin Zhao 《Optics Communications》2010,283(23):4619-4625
Image block matching is one of the motion estimation methods for video inter-frame coding and digital image stabilization. The methods used for matching and searching will greatly affect the accuracy and speed of block matching. The block matching method based on the oblique vectors is suggested in this paper where matching parameters contain both horizontal and vertical vectors in the image blocks at the same time. Improved matching information can be obtained after making correlative calculations in the oblique direction. A novel search method of matching block based on the idea of simulated annealing is presented in this paper to improve the searching speed, accuracy and robustness in the fast operation of the block-matching motion estimation. The simulated annealing algorithm can easily escape from the trap of local minima effectively. With the two methods the block matching can be used for motion estimation at the real-time image processing system and high estimation accuracy can be achieved. An image stabilization system based on DSP (Digital Signal Processing) system is developed to verify this algorithm. Results show that both the matching accuracy and the search speed are improved with the methods presented. 相似文献
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用于数码相机的瞳孔控制自动对焦技术 总被引:4,自引:1,他引:3
对焦窗口的选择是数码相机进行自动对焦的关键问题之一。现有的对焦窗口的选择方法过于简单,由于成像目标的复杂性,有必要使对焦窗口的选择本身实现自动化和智能化[1]。提出了一种利用数字图像处理来进行瞳孔控制自动对焦的方法。对现有照相机结构稍加改进后,可以利用数码相机中现有的CCD/CMOS图像传感器获取拍摄者眼睛的图像,再通过对拍摄者眼睛的图像进行处理来判断其瞳孔在眼睛中的位置。根据这一位置信息,可以推断拍摄者的注意力所集中的区域,从而对焦窗口的自动选择。 相似文献
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Marc Bernheim 《辐射效应与固体损伤》2013,168(1-4):11-17
It is well known that more and more precise doping is needed for producing high performance's electronic components and circuits of increasingly enhanced complexity. An ion optic can be used to directly produce a localised implantation allowing to free one self from all masking techniques. The experimental set up mainly consist in a projecting lens which focuses the reduced image of a “model”, structure partially transparent to the ion beam, on the crystal to be implanted. One of the difficult points is connected with the tine control of the focusing of the ion image on the surface of the target. In order to check this focusing an “Ion Image Converter” is used as the projection lens. On the one hand the 10 keV energy positive ion beam is post accelerated to a hundred keV as it is focused on the target; on the other hand, the secondary electrons ejected from the target are accelerated and focused backwards permitting the formation of an electron image which is an enlargement of the ion figure projected on the target; this auxiliary image after further magnification is observed on a fluorescent screen allowing to adjust and to control the focusing and the illumination of the ion image. 相似文献
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Image segmentation plays a central role in a broad range of applications, such as medical image analysis, autonomous vehicles, video surveillance and augmented reality. Portrait segmentation, which is a subset of semantic image segmentation, is widely used as a preprocessing step in multiple applications such as security systems, entertainment applications, video conferences, etc. A substantial amount of deep learning-based portrait segmentation approaches have been developed, since the performance and accuracy of semantic image segmentation have improved significantly due to the recent introduction of deep learning technology. However, these approaches are limited to a single portrait segmentation model. In this paper, we propose a novel approach using an ensemble method by combining multiple heterogeneous deep-learning based portrait segmentation models to improve the segmentation performance. The Two-Models ensemble and Three-Models ensemble, using a simple soft voting method and weighted soft voting method, were experimented. Intersection over Union (IoU) metric, IoU standard deviation and false prediction rate were used to evaluate the performance. Cost efficiency was calculated to analyze the efficiency of segmentation. The experiment results show that the proposed ensemble approach can perform with higher accuracy and lower errors than single deep-learning-based portrait segmentation models. The results also show that the ensemble of deep-learning models typically increases the use of memory and computing power, although it also shows that the ensemble of deep-learning models can perform more efficiently than a single model with higher accuracy using less memory and less computing power. 相似文献
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光纤近场测量中自动聚焦系统的研究 总被引:2,自引:0,他引:2
在用近场法测量光纤几何尺寸时,关键在于调节光学系统,获得优质的光纤近场图象.而要使这样的测量系统实现自动化,关键在于寻找图象是否清晰的适当判据,继而构成自动调节与控制的闭环反馈系统.本文介绍了利用信息熵判别函数,可以较好地判断图象质量,从而实现了自动调焦和自动测量. 相似文献
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Optics is a potential candidate in information, data, and image processing. In all-optical data and information processing, optics has been used as information carrying signal because of its inherent advantages of parallelism. Several optical methods are proposed in support of the above processing. In many algebraic,arithmetic, and image processing schemes fundamental logic and memory operations are conducted exploring all-optical devices. In this communication we report an all-optical matrix multiplication operation with non-linear material based switching circuit. 相似文献