阈值标记的分水岭彩色图像分割

目的 针对传统分水岭算法中产生的过分割问题,提出一种基于阈值标记的分水岭彩色图像分割算法。方法 该方法将分水岭算法直接应用到原始梯度图像上而不是简化之后的图像,这样做的目的是可以保护边缘信息不受损失;利用不同尺寸结构元求取彩色图像形态学梯度,解决了关于保护边缘和图像简化之间的矛盾。同时算法设计一种阈值自动选取与标记提取方法,从梯度的低频成分中提取与物体相关的局部极小值,用这些极小值构成的二值图像强制标定原始梯度图像,在修改后的梯度上进行分水岭分割。结果 在仿真实验中,利用本文算法针对不同RGB彩色图像进行分割,获得准确、连续封闭的分割边界,与其他同类方法相比,得到符合人类视觉的最小分割区域数,同时在运行效率上也有很大提高。结论 该方法可以自适应提取标记而不需要先验知识,有效解决了分水岭算法的过分割问题,相对于传统的算法,提高了分割性能,有较好的适用性和鲁棒性,可将其应用于机器视觉、生物医学以及高光谱遥感图像分割领域。     

一种遗传优化和Ostu的图像模糊边缘特征提取方法

边缘检测是图像预处理的重要内容之一,在对Pal和King经典模糊边缘检测算法改进的基础上,提出了一种基于遗传算法和Otsu进行图像阈值选取,以不同阈值为基准确定出线性隶属函数,对多峰图像确定多阈值隶属函数的方法,进行模糊增强,从而提取边缘,实验结果表明该算法不仅提高了边缘提取质量,而且缩短了阈值选取时间,是一种有效性、正确性的图像处理方法。     

Coupled region-edge shape priors for simultaneous localization and figure-ground segmentation

We propose a new algorithm for simultaneous localization and figure-ground segmentation where coupled region-edge shape priors are involved with two different but complementary roles. We resort to a segmentation-based hypothesis-and-test paradigm in this research, where the region prior is used to form a segmentation and the edge prior is used to evaluate the validity of the formed segmentation. Our fundamental assumption is that the optimal shape-constrained segmentation that maximizes the agreement with the edge prior occurs at the correctly hypothesized location. Essentially, the proposed algorithm addresses a mid-level vision issue that aims at producing a map image for part detection useful for high-level vision tasks. Our experiments demonstrated that this algorithm offers promising results in terms of both localization and segmentation.     

An image segmentation method using automatic threshold based on improved genetic selecting algorithm

In this paper, an image segmentation method using automatic threshold based on improved genetic selecting algorithm is presented. Optimal threshold for image segmentation is converted into an optimization problem in this new method. In order to achieve good effects for image segmentation, the optimal threshold is solved by using optimizing efficiency of improved genetic selecting algorithm that can achieve a global optimum. The genetic selecting algorithm is optimized by using simulated annealing temperature parameters to achieve appropriate selective pressures. Encoding, crossover, mutation operator and other parameters of genetic selecting algorithm are improved moderately in this method. It can overcome the shortcomings of the existing image segmentation methods, which only consider pixel gray value without considering spatial features and large computational complexity of these algorithms. Experiment results show that the new algorithm greatly reduces the optimization time, enhances the anti-noise performance of image segmentation, and improves the efficiency of image segmentation. Experimental results also show that the new algorithm can get better segmentation effect than that of Otsu’s method when the gray-level distribution of the background follows normal distribution approximately, and the target region is less than the background region. Therefore, the new method can facilitate subsequent processing for computer vision, and can be applied to realtime image segmentation.     

公路视觉导航中道路图像的阈值分割

在公路视觉导航中,分割道路图像的分道线与路面是至关重要。在采用传统最优阈值分割算法时,因道路图像远处与近处的对比度存在差异,易导致不完全分割。为了解决上述问题,针对道路图像的特性提出了逐行最优阈值分割思想。该文通过对大量视频图像的道路与分道线特点进行统计,并结合公路视觉导航中图像的序列性,对逐行最优阈值分割进行了改进以提高实时性,提出了一种新的基于视频流的多阈值分割算法。通过对三种方法对比试验,表明该方法有很好的实时性、有效性和自适应性。     

渐进式前景更新和区域关联的图像协同分割

目的 图像协同分割技术是通过多幅参考图像以实现前景目标与背景区域的分离，并已被广泛应用于图像分类和目标识别等领域中。不过，现有多数的图像协同分割算法只适用于背景变化较大且前景几乎不变的环境。为此，提出一种新的无监督协同分割算法。方法 本文方法是无监督式的，在分级图像分割的基础上通过渐进式优化框架分别实现前景和背景模型的更新估计，同时结合图像内部和不同图像之间的分级区域相似度关联进一步增强上述模型估计的鲁棒性。该无监督的方法不需要进行预先样本学习，能够同时处理两幅或多幅图像且适用于同时存在多个前景目标的情况，并且能够较好地适应前景物体类的变化。结果 通过基于iCoseg和MSRC图像集的实验证明，该算法无需图像间具有显著的前景和背景差异这一约束，与现有的经典方法相比更适用于前景变化剧烈以及同时存在多个前景目标等更为一般化的图像场景中。结论 该方法通过对分级图像分割得到的超像素外观分布分别进行递归式估计来实现前景和背景的有效区分，并同时融合了图像内部以及不同图像区域之间的区域关联性来增加图像前景和背景分布估计的一致性。实验表明当前景变化显著时本文方法相比于现有方法具有更为鲁棒的表现。     

Automated 3D region growing algorithm based on an assessment function

A new region growing algorithm is proposed for the automated segmentation of three-dimensional images. No initial parameters such as the homogeneity threshold or the seeds location have to be adjusted. The principle of our method is to build a region growing sequence by increasing the maximal homogeneity threshold from a very small value to a large one. On each segmented region, a 3D parameter that has been validated on a test image assesses the segmentation quality. This set of values called assessment function is used to determine of the optimal homogeneity criterion. Our algorithm was tested on 3D MR images for the segmentation of trabecular bone samples in order to quantify osteoporosis. A comparison to automated and manual thresholding showed that our algorithm performs better. Its main advantages are to eliminate isolated points due to the noise and to preserve connectivity of the bone structure.     

Image Thresholding by Maximizing the Index of Nonfuzziness of the 2-D Grayscale Histogram

Image segmentation plays an important role in various image processing applications including robot vision and document image analysis and understanding. In contrast to classical set theory, fuzzy set theory, which takes into account the uncertainty intrinsic to various images, has found great success in the area of image thresholding. In this paper, an image thresholding approach based on the index of nonfuzziness maximization of the 2-D grayscale histogram is proposed. The threshold vector (T, S), where T is a threshold for pixel intensity and S is another threshold for the local average of pixels, is obtained by an exhaustive searching algorithm. In this approach, the difference between these two components (T and S) is guaranteed to be within a relatively small range, which leads to reasonable results from the viewpoint of human vision perception. This cannot be achieved in certain entropy-based methods. Experimental results have shown that our proposed approach not only performs well and effectively but also is more robust when applied to noisy images.     

基于YOLOv5和FCN-DenseNet水下图像多目标语义分割算法

带视觉系统的水下机器人作业离不开对水下目标准确的分割,但水下环境复杂,场景感知精度和识别精度不高等问题会严重影响目标分割算法的性能.针对此问题本文提出了一种综合YOLOv5和FCN-DenseNet的多目标分割算法.本算法以FCN-DenseNet算法为主要分割框架, YOLOv5算法为目标检测框架.采用YOLOv5算法检测出每个种类目标所在位置;然后输入针对不同类别的FCN-DenseNet语义分割网络,实现多分支单目标语义分割,最后融合分割结果实现多目标语义分割.此外,本文在Kaggle竞赛平台上的海底图片数据集上将所提算法与PSPNet算法和FCN-DenseNet算法两种经典的语义分割算法进行了实验对比.结果表明本文所提的多目标图像语义分割算法与PSPNet算法相比,在MIoU和IoU指标上分别提高了14.9%和11.6%;与FCN-DenseNet算法在MIoU和IoU指标上分别提高了8%和7.7%,更适合于水下图像分割.     

Robust Higher Order Potentials for Enforcing Label Consistency

This paper proposes a novel framework for labelling problems which is able to combine multiple segmentations in a principled manner. Our method is based on higher order conditional random fields and uses potentials defined on sets of pixels (image segments) generated using unsupervised segmentation algorithms. These potentials enforce label consistency in image regions and can be seen as a generalization of the commonly used pairwise contrast sensitive smoothness potentials. The higher order potential functions used in our framework take the form of the Robust P ⁿ model and are more general than the P ⁿ Potts model recently proposed by Kohli et al. We prove that the optimal swap and expansion moves for energy functions composed of these potentials can be computed by solving a st-mincut problem. This enables the use of powerful graph cut based move making algorithms for performing inference in the framework. We test our method on the problem of multi-class object segmentation by augmenting the conventional crf used for object segmentation with higher order potentials defined on image regions. Experiments on challenging data sets show that integration of higher order potentials quantitatively and qualitatively improves results leading to much better definition of object boundaries. We believe that this method can be used to yield similar improvements for many other labelling problems.     

一种用于彩色图像目标识别的自适应阈值分割方法

机器人视觉系统利用颜色、形状等信息来识别环境目标,但是难点在于识别的鲁棒性和实时性的保证。采用移动机器人做平台,提出一种基于颜色学习的实时目标识别系统,并提出了一种目标颜色学习和分割算法,该算法基于自适应阈值分割图像,考虑环境的光照变化进行调整,改善了系统的实时性和鲁棒性。     

一种改进的多尺度梯度矢量流模型

梯度矢量流主动轮廓线模型是广泛应用于数字图像处理的一种目标轮廓跟踪算法,但易受干扰噪声及虚假边缘的影响,在结合多尺度图像分析的基础上,利用改进的梯度矢量流场,提出了一种改进的主动轮廓线模型。实验表明,该方法较好的限制了非目标边缘和噪声干扰的影响,提高了模型分割的精确性,具有较好的分割效果。     

Segmentation of weather radar image based on hazard severity using RDE: reconstructed mutation strategy for differential evolution algorithm

Weather describes the condition of our atmosphere during a specific period of time, and climate represents a composite of day to day weather over longer period of time. Climatology attempts to analyze and explain the impact of climate so that the society can plan accordingly. Climatology analysis is often done on radar images representing various climatic conditions. These images contain varying scale of severity for any specific climatic parameter of study. The climatologists often find it convenient to analyze climatic conditions if tools are available to segment the weather images based on the severity scale which is represented by different colors. Segmentation of the weather radar image is also used for automated analysis of weather conditions. Differential evolution (DE) approach instead is used for fast selection of optimal threshold. In present paper, we have applied DE with multilevel thresholding for weather image segmentation which results in minimum computational time and excellent image quality. A new mutation strategy for DE named reconstructed differential evolution (RDE) strategy is suggested for better performance over image segmentation. Using fuzzy entropy and RDE for multilevel thresholding provides better results in comparison with last suggested methods.

     

Interactive image segmentation by maximal similarity based region merging

Efficient and effective image segmentation is an important task in computer vision and object recognition. Since fully automatic image segmentation is usually very hard for natural images, interactive schemes with a few simple user inputs are good solutions. This paper presents a new region merging based interactive image segmentation method. The users only need to roughly indicate the location and region of the object and background by using strokes, which are called markers. A novel maximal-similarity based region merging mechanism is proposed to guide the merging process with the help of markers. A region R is merged with its adjacent region Q if Q has the highest similarity with Q among all Q's adjacent regions. The proposed method automatically merges the regions that are initially segmented by mean shift segmentation, and then effectively extracts the object contour by labeling all the non-marker regions as either background or object. The region merging process is adaptive to the image content and it does not need to set the similarity threshold in advance. Extensive experiments are performed and the results show that the proposed scheme can reliably extract the object contour from the complex background.     

An efficient method for segmentation of images based on fractional calculus and natural selection

Image segmentation has been widely used in document image analysis for extraction of printed characters, map processing in order to find lines, legends, and characters, topological features extraction for extraction of geographical information, and quality inspection of materials where defective parts must be delineated among many other applications. In image analysis, the efficient segmentation of images into meaningful objects is important for classification and object recognition. This paper presents two novel methods for segmentation of images based on the Fractional-Order Darwinian Particle Swarm Optimization (FODPSO) and Darwinian Particle Swarm Optimization (DPSO) for determining the n-1 optimal n-level threshold on a given image. The efficiency of the proposed methods is compared with other well-known thresholding segmentation methods. Experimental results show that the proposed methods perform better than other methods when considering a number of different measures.     

Globally Optimal Geodesic Active Contours

An approach to optimal object segmentation in the geodesic active contour framework is presented with application to automated image segmentation. The new segmentation scheme seeks the geodesic active contour of globally minimal energy under the sole restriction that it contains a specified internal point p_int. This internal point selects the object of interest and may be used as the only input parameter to yield a highly automated segmentation scheme. The image to be segmented is represented as a Riemannian space S with an associated metric induced by the image. The metric is an isotropic and decreasing function of the local image gradient at each point in the image, encoding the local homogeneity of image features. Optimal segmentations are then the closed geodesics which partition the object from the background with minimal similarity across the partitioning. An efficient algorithm is presented for the computation of globally optimal segmentations and applied to cell microscopy, x-ray, magnetic resonance and cDNA microarray images.Ben Appleton received degrees in engineering and in science from the University of Queensland in 2001 and was awarded a university medal. In 2002 he began a Ph.D at the University of Queensland in the field of image analysis. He is supported by an Australian Postgraduate Award and the Commonwealth Scientific and Industrial Research Organisation (CSIRO), Mathematical and Information Sciences. He has been a teaching assistant in image analysis at the University of Queensland since 2001. He has also contributed 10 research papers to international journals and conferences and was recently awarded the prize for Best Student Paper at Digital Image Computing: Techniques and Applications. His research interests include image segmentation, stereo vision and algorithms.Hugues Talbot received the engineering degree from École Centrale de Paris in 1989, the D.E.A. (Masters) from University Paris VI in 1990 and the Ph.D from École des Mines de Paris in 1993, under the guidance of Dominique Jeulin and Jean Serra. He has been affiliated with the Commonwealth Scientific and Industrial Research Organisation (CSIRO), Mathematical and Information Sciences since 1994. He has worked on numerous applied projects in relation with industry, he has contributed more than 30 research papers in international journals and conferences and he has co-edited two sets of international conference proceedings on image analysis. He now also teaches image processing at the University of Sydney, and his research interest include image segmentation, linear structure analysis, texture analysis and algorithms.     

强光照条件下智能车辆导航路径图像分割方法

OTSU法（最大类间方差法）被认为是图像分割中阈值自动选取的最优方法之一,针对自主开发的视觉导航区域交通智能车辆（Cyber Car）的导航路径在强光照条件下不能直接应用此方法取得准确分割效果的问题,提出了一种基于区域的罗伯特梯度算子的图像分割方法。分割实验表明,与OTSU法分割效果相比,采用的图像分割方法能够准确地对强光照条件下的导航路径图像进行分割,并具有更好的实时性。     

基于分水岭算法的灵武长枣图像分割方法研究

传统分水岭算法常常会因阈值选择不当而导致图像分割出现各种各样的问题,尤其是过分割问题。在传统分水岭算法的基础上,以灵武长枣图像为研究对象,运用遗传算法对随机选取的阈值进行优化选择;对自然光照环境下的20幅灵武长枣图像,采用改进后的分水岭算法对其进行分割。首先在传统分水岭算法的基础上,利用遗传算法对阈值进行寻优,得到最优的图像分割阈值,再利用最大类间方差法和数学形态学等方法对图像进行后处理,最终得到分割图像,将分割图像与人工分割得到的图像进行比较,分割的正确率能达到89.99%,且分割效果远远优于传统分水岭算法。实验表明,该方法能够得到最优分割阈值并且能够满足机器识别对图像分割的要求。     

Monotonic sequences for image enhancement and segmentation

Both image enhancement and image segmentation are important pre-processing steps for various image processing fields including autonomous navigation, remote sensing, computer vision, and biomedical image analysis. Both methods have their merits and their short comings. It then becomes obvious to ask the question: is it possible to develop a new better image enhancement method which has the key elements from both segmentation and image enhancement techniques? The choice of the threshold level is a key task in image segmentation. There are other challenges of image segmentation. For example, it is very difficult to perform the image segmentation in poor data such as shadows and noise. Recently, a homothetic curves Fibonacci-based cross sections thresholding has been developed for the de-noising purposes. Is it possible to develop a new image cross sections thresholding method, which can be used for both segmentation and image enhancement purposes? This paper a) describes a unified approach for signal thresholding, b) extends cross sections concept by generating and using a new class of monotonic, piecewise linear, sequences (slowly or faster growing than Fibonacci numbers) of numbers; c) uses the extended sections concept to the image enhancement and segmentation applications. Extensive experimental evaluation demonstrates that the newly proposed monotonic sequences have great potential in image processing applications, including image segmentation and image enhancement applications. Moreover, study has shown that the generalized cross techniques are invariant under morphological transformations such as erosion, dilation, and median, able to be described analytically, can be implemented by using the look up table methods.     

基于最大方差法和改进遗传算法的图像分割

针对应用标准遗传算法对一幅灰度图像寻找最优阈值时经常陷入局部寻优的问题,提出了一种利用最大方差法和新的改进遗传算法相结合对图像进行分割的方法.以灰度图像的最大方差作为适应度函数,把图像分割问题变成一个优化问题.利用遗传算法的寻优高效性,搜索到能使分割质量达到最优的分割阈值.实验结果表明,采用新的改进遗传算法和最大方差法相结合对图像搜索全局阈值时能收敛至全局最优解,并且大大缩短寻找最优阈值的时间.