Visual saliency guided normal enhancement technique for 3D shape depiction

Visual saliency can effectively guide the viewer's visual attention to salient regions of a 3D shape. Incorporating the visual saliency measure of a polygonal mesh into the normal enhancement operation, a novel saliency guided shading scheme for shape depiction is developed in this paper. Due to the visual saliency measure of the 3D shape, our approach will adjust the illumination and shading to enhance the geometric salient features of the underlying model by dynamically perturbing the surface normals. The experimental results demonstrate that our non-photorealistic shading scheme can enhance the depiction of the underlying shape and the visual perception of its salient features for expressive rendering. Compared with previous normal enhancement techniques, our approach can effectively convey surface details to improve shape depiction without impairing the desired appearance.     

Visual salience guided feature-aware shape simplification

In the area of 3D digital engineering and 3D digital geometry processing, shape simplification is an important task to reduce their requirement of large memory and high time complexity. By incorporating the content-aware visual salience measure of a polygonal mesh into simplification operation, a novel feature-aware shape simplification approach is presented in this paper. Owing to the robust extraction of relief heights on 3D highly detailed meshes, our visual salience measure is defined by a center-surround operator on Gaussian-weighted relief heights in a scale-dependent manner. Guided by our visual salience map, the feature-aware shape simplification algorithm can be performed by weighting the high-dimensional feature space quadric error metric of vertex pair contractions with the weight map derived from our visual salience map. The weighted quadric error metric is calculated in a six-dimensional feature space by combining the position and normal information of mesh vertices. Experimental results demonstrate that our visual salience guided shape simplification scheme can adaptively and effectively re-sample the underlying models in a feature-aware manner, which can account for the visually salient features of the complex shapes and thus yield better visual fidelity.     

基于视觉显著性的水面垃圾目标检测

针对实际水面复杂环境提出了一种基于视觉显著性的水面垃圾目标检测算法。首先对输入图像进行超像素分割,在CIELab、RGB和HSV颜色空间中提取超像素级的显著性特征,然后使用随机森林回归器将显著性特征进行融合得到疑似显著性图,并使用自适应阈值分割得到疑似二值显著性图,最后使用MLP分类器对原始图像中的疑似垃圾目标区域进行判别,去除水波、倒影和反光的干扰,最终检测出水面的垃圾目标。实验结果表明所提基于视觉显著性的水面垃圾目标检测算法的性能优于其他水面目标检测算法。     

A biologically inspired object-based visual attention model

A biologically inspired object-based visual attention model is proposed in this paper. This model includes a training phase and an attention phase. In the training phase, all training targets are fused into a target class and all training backgrounds are fused into a background class. Weight vector is computed as the ratio of the mean target class saliency and the mean background class saliency for each feature. In the attention phase, for an attended scene, all feature maps are combined into a top-down salience map with the weight vector by a hierarchy method. Then, top-down and bottom-up salience map are fused into a global salience map which guides the visual attention. At last, the size of each salient region is obtained by maximizing entropy. The merit of our model is that it can attend a class target object which can appear in the corresponding background class. Experimental results indicate that: when the attended target object doesn’t always appear in the background corresponding to that in the training images, our proposed model is excellent to Navalpakkam’s model and the top-down approach of VOCUS.     

自动特征选择和加权的图像显著区域检测

视觉显著性度量是图像显著区域提取中的一个关键问题,现有的方法主要根据图像的底层视觉特征,构造相应的显著图。不同的特征对视觉显著性的贡献是不同的,为此提出一种能够自动进行特征选择和加权的图像显著区域检测方法。提取图像的亮度、颜色和方向等特征,构造相应的特征显著图。提出一种新的特征融合策略,动态计算各特征显著图的权值,整合得到最终的显著图,检测出图像中的显著区域。在多幅自然图像上进行实验,实验结果表明,该方法在运算速度和检测效果方面都取得了不错的效果。     

Autonomous Salient Feature Detection through Salient Cues in an HSV Color Space for Visual Indoor Simultaneous Localization and Mapping

For successful simultaneous localization and mapping (SLAM), perception of the environment is important. This paper proposes a scheme to autonomously detect visual features that can be used as natural landmarks for indoor SLAM. First, features are roughly selected from the camera image through entropy maps that measure the level of randomness of pixel information. Then, the saliency of each pixel is computed by measuring the level of similarity between the selected features and the given image. In the saliency map, it is possible to distinguish the salient features from the background. The robot estimates its pose by using the detected features and builds a grid map of the unknown environment by using a range sensor. The feature positions are stored in the grid map. Experimental results show that the feature detection method proposed in this paper can autonomously detect features in unknown environments reasonably well.     

融入频域信息聚焦特征的显著性目标检测算法

由于视觉注意预测能够快速、准确地定位图像中的显著区域,因此将视觉注意中的频域信息融入显著性目标检测中,从而有效地在复杂场景中检测显著性目标。首先,采用改进的频域检测方法对图像进行视觉注意预测,将该频域信息融入Focusness特征中计算得到频域信息聚焦特征,并将此特征与颜色特征进行融合得到前景显著图。然后,对RBD背景进行优化,得到背景显著图。最后,对前景显著图、背景显著图进行融合。在ESSCD,DUT-OMON两个具有挑战性的数据集上进行了大量实验,并采用PR_Curve,F-Measure,MAE对结果进行了评估,结果表明,所提出的方法要优于6种对比方法(HFT,PQFT,HDCT,UFO,DSR和RBD),并且能够处理复杂场景的图像。     

基于视觉显著性特征的快速场景配准方法

视觉显著性特征是模拟生物视觉注意力选择机制的一种具有较好的鲁棒性与不变性的视觉特征。基于视觉显著性特征提出了一种快速的场景配准方法。该方法采用调幅傅里叶变换构造视觉显著性映射;通过对显著特征局部极值特性以及信息丰度的分析,实现显著点的粗定位、预选择与可信度排序;通过图像形态学操作,实现了显著场景区域的生长与合并。在此基础上,提出了SSIFT(saliency scale invariant feature transform）算法,从而减少了场景分类算法的计算量。利用本文方法对美国南加州大学的场景数据库进行测试,实验结果表明这种方法提取的SSIFT特征对于图像的平移、旋转以及光照等变化具有良好的不变性;与经典SIFT算法相比,该方法在计算速度上具有明显的优势,并在识别率上也略优于SIFT算法。     

利用视觉显著性的图像分割方法

提出一种利用视觉显著性对图像进行分割的方法。首先提取图像的底层视觉特征,从局部显著性、全局显著性和稀少性3个方面计算各特征图像中各像素的视觉显著性,得到各特征显著图;对各特征显著图进行综合,生成最终的综合显著图。然后对综合显著图进行阈值分割,得到二值图像,将二值图像与原始图像叠加,将前景和背景分离,得到图像分割结果。在多幅自然图像上进行实验验证,并给出相应的实验结果和分析。实验结果表明,该方法正确有效,具有和人类视觉特性相符合的分割效果。     

融合双目多维感知特征的立体视频显著性检测

目的 立体视频能提供身临其境的逼真感而越来越受到人们的喜爱,而视觉显著性检测可以自动预测、定位和挖掘重要视觉信息,可以帮助机器对海量多媒体信息进行有效筛选。为了提高立体视频中的显著区域检测性能,提出了一种融合双目多维感知特性的立体视频显著性检测模型。方法 从立体视频的空域、深度以及时域3个不同维度出发进行显著性计算。首先,基于图像的空间特征利用贝叶斯模型计算2D图像显著图;接着,根据双目感知特征获取立体视频图像的深度显著图;然后,利用Lucas-Kanade光流法计算帧间局部区域的运动特征,获取时域显著图;最后,将3种不同维度的显著图采用一种基于全局-区域差异度大小的融合方法进行相互融合,获得最终的立体视频显著区域分布模型。结果 在不同类型的立体视频序列中的实验结果表明,本文模型获得了80%的准确率和72%的召回率,且保持了相对较低的计算复杂度,优于现有的显著性检测模型。结论 本文的显著性检测模型能有效地获取立体视频中的显著区域,可应用于立体视频/图像编码、立体视频/图像质量评价等领域。     

Saliency and KAZE features assisted object segmentation

In this paper, we propose an unsupervised salient object segmentation approach using saliency and object features. In the proposed method, we utilize occlusion boundaries to construct a region-prior map which is then enhanced using object properties. To reject the non-salient regions, a region rejection strategy is employed based on the amount of detail (saliency information) and density of KAZE keypoints contained in them. Using the region rejection scheme, we obtain a threshold for binarizing the saliency map. The binarized saliency map is used to form a salient superpixel cluster. Finally, an iterative grabcut segmentation is applied with salient texture keypoints (SIFT keypoints on the Gabor convolved texture map) supplemented with salient KAZE keypoints (keypoints inside saliency cluster) as the foreground seeds and the binarized saliency map (obtained using the region rejection strategy) as a probably foreground region. We perform experiments on several datasets and show that the proposed segmentation framework outperforms the state of the art unsupervised salient object segmentation approaches on various performance metrics.     

基于区域对比信息混合编码的图像显著性检测方法

图像显著性检测是为了检测到能够引起视觉注意力的对象区域,利用混合的特征编码能够避免单一的特征编码在检测图像中对象显著性和显著区域精确边界时候的不足。提出一种基于图像区域对比信息和图像语义信息混合编码的图像显著性检测方法。结合图像对比信息编码以及原始图像的语义信息编码,通过卷积神经网络来进行图像显著性检测,保证对显著对象进行有效的检测以及对显著区域边缘细节的处理能力。实验结果表明,在主流的显著性检测数据集上,采用该方法能够有效地检测到图像中的显著对象以及显著区域的精确边界。     

Infrared ship target segmentation through integration of multiple feature maps

We investigate the issue of ship target segmentation in infrared (IR) images, and propose an efficient method based on feature map integration. It consists of mainly two procedures: salient region detection based on multiple feature map integration and salient region segmentation based on locally adaptive thresholding. Firstly, a saliency map is constructed by integrating multiple features of IR ship targets, including gray level intensity, local contrast, salient linear structures, and edge strength. Secondly, we propose an adaptive thresholding method to segment each local salient region, and a target selection procedure based on shape features is used to remove background and obtain the true target. Experimental results show that the proposed method performs well for IR ship target segmentation. The advantage of the proposed method is demonstrated in both visual and quantitative comparisons, especially for IR images with a bright background or a ship target close to port.     

幂律变换和IGLC算法的显著性目标检测方法

针对显著性检测方法生成显著图存在对比度低、目标区域细节不明显、检测区域不准、背景抑制效果不足的问题，提出幂律变换和IGLC算法的显著性目标检测方法。利用幂律变换函数优化IG算法，彻底抑制显著图的背景区域。经二值化处理的显著图在原图像分割，得到感兴趣目标分割图；LC算法优化感兴趣目标分割图，得到细节佳的显著图；利用自适应烟花算法增强显著目标区域的对比度，生成最终的显著图。对标准测试数据集MSRA10K和PASCAL-S数据集中的图像进行显著性目标检测实验，且与目前较流行的6种显著性目标检测方法进行主观和客观的对比分析，分析结果均优于对比方法。该算法得到的显著图既具有对比度和细节增强的效果，又具有背景抑制效果更好的优点。     

基于对数Gabor的超复数视觉显著性检测算法

为在没有先验知识的情况下准确获取图像显著性目标,提出一种基于对数Gabor滤波器和超复数傅里叶变换的视觉显著性检测算法。利用对数Gabor滤波器模仿人类视觉感受野,对输入图像进行预处理,提取颜色、纹理方向等特征。根据所得特征构造各尺度下的超复数图像,并求其傅里叶变换相位谱,将多尺度超复数相位谱反变换后进行归一化,从而获得视觉显著图。实验结果表明,该算法与传统的算法相比具有更高的准确率,应用于复杂场景下的交通标志检测能取得较好的检测效果。     

A dynamic saliency attention model based on local complexity

A dynamic saliency attention model based on local complexity is proposed in this paper. Low-level visual features are extracted from current and some previous frames. Every feature map is resized into some different sizes. The feature maps in same size and same feature for all the frames are used to calculate a local complexity map. All the local complexity maps are normalized and are fused into a dynamic saliency map. In the same time, a static saliency map is acquired by the current frame. Then dynamic and static saliency maps are fused into a final saliency map. Experimental results indicate that: when there is noise among the frames or there is change of illumination among the frames, our model is excellent to Marat?s model and Shi?s model; when the moving objects do not belong to the static salient regions, our model is better than Ban?s model.     

Saliency-Based Fidelity Adaptation Preprocessing for Video Coding

In this paper,we present a video coding scheme which applies the technique of visual saliency computation to adjust image fidelity before compression.To extract visually salient features,we construct a spatio-temporal saliency map by analyzing the video using a combined bottom-up and top-down visual saliency model.We then use an extended bilateral filter,in which the local intensity and spatial scales are adjusted according to visual saliency,to adaptively alter the image fidelity.Our implementation is based on the H.264 video encoder JM12.0.Besides evaluating our scheme with the H.264 reference software,we also compare it to a more traditional foreground-background segmentation-based method and a foveation-based approach which employs Gaussian blurring.Our results show that the proposed algorithm can improve the compression ratio significantly while effectively preserving perceptual visual quality.     

基于视觉显著性图与似物性的对象检测

为了能够准确地检测出图像中的显著性对象,提出了一种新的基于视觉显著性图与似物性的对象检测算法。该算法首先在图像上提取大量具有较高似物性度量的矩形窗口,并估算出对象可能出现的位置,将窗口级的似物性度量转换到像素级的似物性度量;然后把原始显著性图与像素级的似物性图进行融合,生成加权显著性图,分别二值化原始显著性图和加权显著性图,利用凸包检测得到最大查找窗口区域与种子窗口区域;最后结合边缘概率密度搜索出最优的对象窗口。在公开数据集MSRA-B上的实验结果表明,该算法在准确率、召回率以及F-测度方面优于最大化显著区域检测算法、区域密度最大化算法以及似物性对象检测算法等已有的多种算法。     

基于注意计算模型的医学图像模糊连接度分割

用模糊连接度分割图像时,种子点多以聚类分析方法自动给定,本文分析了传统聚类法存在的问题,在人类视觉活动机制的启发下,提出新的完全不同于聚类方法的视觉显著点注意引导下的图像分割方法.将图像特征显著点的定位转化为概率密度估计问题,引入新的注意计算模型并结合Mean-Shift处理得到关键特征点.注意模型的特征地图采用图像灰度的对比度构成,迭代计算高斯邻域显著度.从密度估计的角度定位显著点,克服以往偏生理注意模型对定量描述的能力不足,尤其适用医学模糊图像.新的方法能完全自动地定位种子点,有效地分割模糊医学图像,提高准确率.