A data mining approach to face detection

In this paper, we propose a novel face detection method based on the MAFIA algorithm. Our proposed method consists of two phases, namely, training and detection. In the training phase, we first apply Sobel's edge detection operator, morphological operator, and thresholding to each training image, and transform it into an edge image. Next, we use the MAFIA algorithm to mine the maximal frequent patterns from those edge images and obtain the positive feature pattern. Similarly, we can obtain the negative feature pattern from the complements of edge images. Based on the feature patterns mined, we construct a face detector to prune non-face candidates. In the detection phase, we apply a sliding window to the testing image in different scales. For each sliding window, if the slide window passes the face detector, it is considered as a human face. The proposed method can automatically find the feature patterns that capture most of facial features. By using the feature patterns to construct a face detector, the proposed method is robust to races, illumination, and facial expressions. The experimental results show that the proposed method has outstanding performance in the MIT-CMU dataset and comparable performance in the BioID dataset in terms of false positive and detection rate.     

基于HSV色彩空间的自适应肤色检测

针对复杂背景彩色图像提出了一种基于HSV色彩空间的自适应肤色检测算法。该算法首先使用阈值在HSV空间对人体肤色区域进行肤色分割,然后对分割出的肤色区域使用相对重要性滤波和自适应区域归并,最后将归并后的肤色区域使用人眼定位进行验证,将多人脸检测转化为单人脸检测。实验结果表明,该算法复杂度较小,对光照变化具有很好的鲁棒性。     

复杂背景下的多人脸检测方法

复杂背景下采用肤色进行人脸检测具有较高的检测率,但同时也具有较高的误检率,而采用AdaBoost算法进行人脸检测从根本上解决了实时性问题,但是检测率不理想。基于上述原因,采用肤色分割与AdaBoost相结合的方法对人脸进行检测：首先采用肤色分割进行人脸粗定位,然后将粗定位后的人脸候选区域作为AdaBoost检测的输入子窗口进行人脸检测。在预处理过程中,采用可调节结构元素,解决了对于不同图像中大小不一的人脸采用固定的结构元素造成的人脸丢失问题。实验结果表明该方法在提高检测率的同时,也降低了误检率。     

An improvement of face detection algorithm for color photos

The problem of automatic detection of regions of interest (ROI) on color photos is considered. The efficiency of Viola-Jones face detector implemented in Intel OpenCV library is analyzed. The image size dependence of the algorithm characteristics is studied. It is shown that there are 2 significant drawbacks of this face detection algorithm as applied to the task mentioned. Some modifications are made for elimination of these drawbacks. To reduce false positives it is proposed to modify the algorithm with color segmentation and human skin tones analysis. To reduce the processing time the algorithm of downsizing preprocessing is proposed.     

基于肤色和类Harr特征的人脸图像的人眼检测

人眼检测在表情识别和计算机视觉领域得到了广泛的关注和研究,但是在多数的人眼检测方法中,对于背景较复杂的图像,识别率急速下降,误检率急剧上升。经过研究,使用椭圆肤色模型预处理图像,分割出肤色区域和非肤色区域,检测算法只对肤色区域进行人眼检测,有效降低了复杂背景造成的高误检率。同时特征选取是决定检测算法识别率和误检率等性能标准的关键因素,选取类Harr特征训练Adaboost级联分类器,实验表明了类Harr特征的有效性。     

基于颜色和特征匹配的视频图像人脸检测实现技术

A face detection method using statistical skin-color model and facial feature matching is presented in this paper.According to skin-color distribution in YUV color space,we develope a statistical skin-color model through interactive sample training and learning.Using this method we convert the color image to binary image and then segment face-candidate regions in the video images.In order to improve the quality of binary image and remove unwanted noises,filtering and mathematical morphology are empolied.After these two processing,we use facial feature matching for further detection.The presence or absence of a face in each region is verified by means of mouth detector based on a template matching method.The experimental results show the proposed method has the features of high speed and high efficiency,but also robust to face variation to some extent.So it is suitable to be applied to real-time face detection and tracking in video sequences.     

基于YCbCr肤色模型和SNOW分类器的人脸检测

人脸检测是人脸识别的首要步骤,在人脸识别领域有重要的应用价值。基于YCbCr彩色空间,提出一种RGB彩色图像的人脸检测方法。该方法利用YCbCr肤色模型进行肤色分割,得到类肤色区域作为侯选人脸区域;结合split up Sparse Network OfWinnows（SNOW）分类器准确定位人脸的位置应用matlab编程技术对多组图像进行实验,结果表明,该方法适用于复杂条件下的人脸检测,并且不受人脸表情的限制,对于多人脸检测同样适用。     

基于肤色和区域双重匹配的人脸检测

提出了一种在复杂背景的图像中自动检测彩色人脸的方法。这种方法将肤色信息与人脸区域信息相结合。先在YCbCr颜色空间中求出图像中每个像素点属于肤色的隶属度,然后求出每个像素点对于质心的区域隶属度,最后把这两个隶属度进行结合得到属于人脸的隶属度。试验结果证明这种方法能较好地在复杂背景中检测出人脸。     

基于肤色和Adaboost算法的人脸检测研究

人脸检测是计算机视觉和人工智能领域中的一项富有挑战性的工作,在虚拟现实、人机交互等很多领域都有广泛的应用。研究了基于Adaboost的人脸检测,并提出了肤色与Adaboost算法相结合的人脸检测方法。对输人的彩色图像进行从RGB空间到YCrCb空间的转换,再结合形态学等方法进行区域肤色分割,排除背景干扰,然后用Adaboost算法对可能区域进行检测,得到人脸位置。实验表明,该方法有较高的准确性和鲁棒性,可以得到满意的检测效果。     

自适应搜索目标的快速彩色复合人脸检测方法

针对AdaBoost人脸检测方法搜索时间较长,不利于在手机等嵌入式平台上应用的现状,提出了一种结合肤色分割、人脸几何特征和AdaBoost的自适应搜索窗口和搜索步长的快速人脸检测方法。该算法在HSV颜色空间对图像进行分割,结合人脸几何特征对分割后的灰度图像进行面积滤波。最后提取滤波后的图像轮廓,结合经验系数得到自适应搜索窗口和搜索步长。实验结果表明,自适应算法不仅能检测出不同尺寸的人脸,而且检测速度快,能节省51.17%的搜索时间。     

基于肤色和支持向量机的人脸检测

人脸检测作为人脸识别系统的重要一环,越来越受到技术研究和商业应用的关注。针对人脸检测环境的复杂性,该文提出了基于肤色和支持向量机的人脸检测算法。该算法对于具有复杂背景信息的人脸彩色图像,采用肤色检测的方法进行肤色区域的分割并去除噪声干扰,然后使用支持向量机(SVM)对于类似肤色区域进一步检测并确定人脸区域。实验表明,结合肤色模型的快速检测和支持向量机的二次验证,该方法能提高人脸检测的准确性,并缩短检测时间。     

基于肤色模型和贝叶斯判别的人脸检测

构造了一个彩色图片的正面人脸检测系统。首先利用肤色在YCbCr空间中沿Y方向的集中分布特性构建肤色信息库，根据该信息库在图像中检测出肤色区域；然后在肤色区域利用贝叶斯特征判别方法进行正面多尺度人脸检测。另外，定义了一些启发式搜索规则，有效地加快了人脸目标的搜索速度。实验证明, 用较少的样本进行训练的人脸检测系统，对有复杂背景、多样化的测试集具有较好的测试效果。     

基于肤色和Haar方差特征的人脸检测

为了在提高复杂背景下的人脸检测率的同时减少检测时间,将肤色分割和Haar方差特征相结合,在YCbCr颜色空间通过椭圆肤色模型和logistic回归分析确定每一点的肤色概率,生成肤色概率图,从而将每一点的像素值映射到[0,1],在Ostu方法的基础上采用并行的遗传算法确定肤色分割的阈值,快速分割出人脸区域;最后用少量的Haar方差特征取代原来的Haar特征,并采用SVM训练分类方法对分割出的人脸区域进行验证。实验表明,该方法不仅提高了人脸检测的正确率,而且具有较快的人脸检测速度。     

500-fps face tracking system

In this paper, we propose a high-speed vision system that can be applied to real-time face tracking at 500 fps using GPU acceleration of a boosting-based face tracking algorithm. By assuming a small image displacement between frames, which is a property of high-frame rate vision, we develop an improved boosting-based face tracking algorithm for fast face tracking by enhancing the Viola–Jones face detector. In the improved algorithm, face detection can be efficiently accelerated by reducing the number of window searches for Haar-like features, and the tracked face pattern can be localized pixel-wise even when the window is sparsely scanned for a larger face pattern by introducing skin color extraction in the boosting-based face detector. The improved boosting-based face tracking algorithm is implemented on a GPU-based high-speed vision platform, and face tracking can be executed in real time at 500 fps for an 8-bit color image of 512 × 512 pixels. In order to verify the effectiveness of the developed face tracking system, we install it on a two-axis mechanical active vision system and perform several experiments for tracking face patterns.     

An efficient face detection based on color-filtering and its application to smart devices

This paper proposes a means of using facial color to enhance conventional face detectors. To detect face rapidly, the proposed approach adopts a color filtering based efficient region scanning method. The scanning method skips over regions that do not contain candidate faces, based on a facial color membership function. Then it adopts a face/non-face classifier using facial color at the preprocessor of the face detector. This classifier has low computational cost and can reject non-face regions at an early stage of face detection. By integrating the proposed face detector with a kernel based object tracker, a real-time face detection and tracking application is implemented for smart devices. The proposed method considerably reduces the overall computation time and reduces the number of false alarms.     

基于特征融合的多尺度窗口产品外观检测方法

为提高产品外观质量的检测精度和实时性,提出一种基于特征融合的多尺度滑动窗口机器视觉检测方法;在训练阶段,首先提取图像的HOG特征和Lab颜色特征,并采用典型相关分析法(CCA)进行特征融合;接下来,采用支持向量机(SVM)对融合的特征进行训练,生成分类器;在检测阶段,产品外观不同区域对精度的要求不同,为提高检测效率,生成不同尺度的滑动窗口,在每个窗口中都进行图像的特征提取与特征融合;最后,对采集的图像序列进行匹配,实现产品外观划痕的实时检测;实验中,选取不同的特征提取方法进行对比,并分别生成大小不同的滑动窗口,通过分析实验结果,结合检测时间与精度,确定各个区域的窗口尺度;实验表明,与传统的检测方法相比,所提方法在检测精度和实时性上具有显著提高。     

Face detection using quantized skin color regions merging andwavelet packet analysis

Detecting and recognizing human faces automatically in digital images strongly enhance content-based video indexing systems. In this paper, a novel scheme for human faces detection in color images under nonconstrained scene conditions, such as the presence of a complex background and uncontrolled illumination, is presented. Color clustering and filtering using approximations of the YCbCr and HSV skin color subspaces are applied on the original image, providing quantized skin color regions. A merging stage is then iteratively performed on the set of homogeneous skin color regions in the color quantized image, in order to provide a set of potential face areas. Constraints related to shape and size of faces are applied, and face intensity texture is analyzed by performing a wavelet packet decomposition on each face area candidate in order to detect human faces. The wavelet coefficients of the band filtered images characterize the face texture and a set of simple statistical deviations is extracted in order to form compact and meaningful feature vectors. Then, an efficient and reliable probabilistic metric derived from the Bhattacharrya distance is used in order to classify the extracted feature vectors into face or nonface areas, using some prototype face area vectors, acquired in a previous training stage     

基于肤色特征和遗传算法的人眼瞳孔定位算法

提出了一种单目摄像头下定位人眼瞳孔的方法,分为人脸区域检测、人眼区域检测、瞳孔中心定位三个阶段。在人脸区域检测阶段,利用人脸的肤色和唇色在不同色度空间下的特性,结合区域增长的方法分割出人脸区域;在人眼区域检测阶段,利用定位出的人脸区域,根据先验知识缩小搜索区域,再结合遗传算法搜索眼部区域;最后利用圆的几何性质定位瞳孔中心。实验结果证明了本算法在复杂背景和头部偏转情况下的有效性。     

基于肤色的人脸检测研究

对于有背景的彩色图像,肤色是人体表面最显著的特征之一,所以肤色特征是人脸检测中一个重要的特征[1～2]。肤色特征主要由肤色模型描述,检测方法可以分为颜色选择,肤色区域分割和人脸检测三个步骤。文章提出的肤色模型可以较好的适应光照变化,采用肤色分割的方法,可以快速检测不同大小,不同平面以及一定侧面旋转角度的人脸。对简单背景下的人脸检测的检测率达到95.65%,复杂背景下的人脸检测的检测率达到85.22%。     

针对机动车驾驶员的人脸检测方法

为了正确检测人脸区域、提高驾驶室内光照不足情况下人脸检测与定位方法的准确性和实时性,采用了肤色聚类的人脸检测方法,利用肤色聚类性将彩色图像分割成皮肤区和非皮肤区。同时,提出一种基于多尺度Retinex算法的改进算法,其能够在人脸检测之前对图像进行光照补偿处理。将改进后的算法应用到新建立的人脸图像库中进行仿真实验,并与传统的肤色聚类人脸检测方法进行对比,其正确率提高了4.7%。实验结果表明:改进后的肤色聚类人脸检测算法可实现对不同光照变化和旋转角度的人脸进行检测,且具有很强的实用价值。