Multi-Layer Feature Extraction with Deformable Convolution for Fabric Defect Detection

In the textile industry,the presence of defects on the surface of fabric is an essential factor in determining fabric quality.Therefore,identifying fabric defects forms a crucial part of the fabric production process.Traditional fabric defect detection algorithms can only detect specific materials and specific fabric defect types;in addition,their detection efficiency is low,and their detection results are relatively poor.Deep learning-based methods have many advantages in the field of fabric defect detection,however,such methods are less effective in identifying multiscale fabric defects and defects with complex shapes.Therefore,we propose an effective algorithm,namely multilayer feature extraction combined with deformable convolution(MFDC),for fabric defect detection.In MFDC,multi-layer feature extraction is used to fuse the underlying location features with high-level classification features through a horizontally connected top-down architecture to improve the detection of multi-scale fabric defects.On this basis,a deformable convolution is added to solve the problem of the algorithm’s weak detection ability of irregularly shaped fabric defects.In this approach,Roi Align and Cascade-RCNN are integrated to enhance the adaptability of the algorithm in materials with complex patterned backgrounds.The experimental results show that the MFDC algorithm can achieve good detection results for both multi-scale fabric defects and defects with complex shapes,at the expense of a small increase in detection time.

Review of Fabric Defect Detection Based on Computer Vision

In textile inspection field,the fabric defect refers to the destruction of the texture structure on the fabric surface.The technology of computer vision makes it possible to detect defects automatically.Firstly,the overall structure of the fabric defect detection system is introduced and some mature detection systems are studied.Then the fabric detection methods are summarized,including structural methods,statistical methods,frequency domain methods,model methods and deep learning methods.In addition,the evaluation criteria of automatic detection algorithms are discussed and the characteristics of various algorithms are analyzed.Finally,the research status of this field is discussed,and the future development trend is predicted.

Feature Extraction of Fabric Defects Based on Complex Contourlet Transform and Principal Component Analysis

To extract features of fabric defects effectively and reduce dimension of feature space,a feature extraction method of fabric defects based on complex contourlet transform （CCT） and principal component analysis （PCA） is proposed.Firstly,training samples of fabric defect images are decomposed by CCT.Secondly,PCA is applied in the obtained low-frequency component and part of highfrequency components to get a lower dimensional feature space.Finally,components of testing samples obtained by CCT are projected onto the feature space where different types of fabric defects are distinguished by the minimum Euclidean distance method.A large number of experimental results show that,compared with PCA,the method combining wavdet low-frequency component with PCA （WLPCA）,the method combining contourlet transform with PCA （CPCA）,and the method combining wavelet low-frequency and highfrequency components with PCA （WPCA）,the proposed method can extract features of common fabric defect types effectively.The recognition rate is greatly improved while the dimension is reduced.

Detection of Fabric Defects with Fuzzy Label Co-occurrence Matrix Set

Co-occurrence matrices have been successfully applied in texture classification and segmentation.However,they have poor computation performance in real-time application.In this paper,the efficient co-occurrence matrix solution for defect detection is focused on,and a method of Fuzzy Label Co-occurrence Matrix (FLCM) set is proposed.In this method,all gray levels are supposed to subject to some fuzzy sets called fuzzy tonal sets and three defective features are defined.Features of FLCM set with various parameters are combined for the final judgment.Unlike many methods,image acquired for learning hasn't to be entirely free of defects.It is shown that the method produces high accuracy and can be a competent candidate for plain colour fabric defect detection.

Automatic Fabric Defects Inspection Machine

The textile industry is one of the most important industries in Sri Lanka.In most of the textile garment factories the defects of the fabrics are detected manually.The manual textile quality control usually depends on eye inspection.Famously,human visual assessment is drawn-out,tiring,and an exhausting errand,including perception,consideration and experience to recognize the fault occurrence.The precision of human visual assessment declines with dull positions and vast schedules.Some of the time slow,costly,and sporadic review is the outcome.In this manner,the programmed automatic visual review safeguards both the fabric quality inspector and the quality.This examination has exhibited that Textile Defect Recognition System is fit for distinguishing fabrics’imperfections with endorsed exactness with viability.With some products 100%inspection is important to ensure the stipulated quality or standard.The classifications for the automated fabric inspection approaches are expanding as the work is vast and complex.According to the algorithm used,the texture analysis problem is classified into different approaches.They are Structural,spectral,model-based methods,Unfortunately,the optimal plan does not yet exist for these vast numbers of applied methods,as each of them has some advantages and disadvantages.

Automatic Image Inspection of Fabric Defects Based on Optimal Gabor Filter

An effective method for automatic image inspection of fabric defects is presented. The proposed method relies on a tuned 2D-Gabor filter and quantum-behaved particle swarm optimization( QPSO) algorithm. The proposed method consists of two main steps:( 1) training and( 2) image inspection. In the image training process,the parameters of the 2D-Gabor filters can be tuned by QPSO algorithm to match with the texture features of a defect-free template. In the inspection process, each sample image under inspection is convoluted with the selected optimized Gabor filter.Then a simple thresholding scheme is applied to generating a binary segmented result. The performance of the proposed scheme is evaluated by using a standard fabric defects database from Cotton Incorporated. Good experimental results demonstrate the efficiency of proposed method. To further evaluate the performance of the proposed method,a real time test is performed based on an on-line defect detection system. The real time test results further demonstrate the effectiveness, stability and robustness of the proposed method,which is suitable for industrial production.

An Enhanced Nonlocal Self-Similarity Technique for Fabric Defect Detection

Fabric defect detection has been an indispensable and important link in fabric production,many studies on the development of vision based automated inspection techniques have been reported.The main drawback of existing methods is that they can only inspect a particular type of fabric pattern in controlled environment.Recently,nonlocal self-similarity(NSS)based method is used for fabric defect detection.This method achieves good defect detection performance for small defects with uneven illumination,the disadvantage of NNS based method is poor for detecting linear defects.Based on this reason,we improve NSS based defect detection method by introducing a gray density function,namely an enhanced NSS(ENSS)based defect detection method.Meanwhile,mean filter is applied to smooth images and suppress noise.Experimental results prove the validity and feasibility of the proposed NLRA algorithm.

Fabric Defect Detection Using Adaptive Wavelet Transform

A method of woven fabric defect detection using the wavelet transform adaptive to the fabric has been developed. With reference to the orthogonality constrains of Daubechies wavelet, by taking the mmimization of the energy or the gray level of the pixels in the output sub-images as the additional conditions and using the random algorithm method, two sets of wavelet filters adapted to the fabric texture were formed. The original images of normal fabric texture and the fabric texture with defects were decomposed into horizontal and vertical sub- images by using these filters and the feature indices of these sub-images were also extracted. By comparing the feature indices of the normal texture with that of the defective texture, the fabric defects can be successfully detected and located.

Fabric Defect Detection Using GMRF Model

It has been testified that the Gauss Markov random field model is most suitable for the characterization of fabric texture among a variety of available models because of its approximately constant character and the normality of the gray-level distribution found with typical fabric images. However, the general Gauss-Markov random field(GMRF) method for fabric defect detection is not always ideal in practice since in some cases, the estimated model parameters make the Markov error covariance not positively definite, which may render the method to fail thoroughly. In this paper, the use of the GMRF model for defect detection of fabric is discussed and an approach to this problem is proposed. Some detailed texture may be overlooked in this way, but good detection results can still be expected as far as fabric defect detection is concerned.

Detection of fabric defects based on frequency-tuned salient algorithm

The correct rate of detection for fabric defect is affected by low contrast of images. Aiming at the problem,frequencytuned salient map is used to detect the fabric defect. Firstly,the images of fabric defect are divided into blocks. Then,the blocks are highlighted by frequency-tuned salient algorithm. Simultaneously,gray-level co-occurrence matrix is used to extract the characteristic value of each rectangular patch. Finally,PNN is used to detect the defect on the fabric image. The performance of proposed algorithm is estimated off-line by two sets of fabric defect images. The theoretical argument is supported by experimental results.

Fabric Defect Detection Using Independent Component Analysis and Phase Congruency

A novel method based on independent component analysis and phase congruency is proposed for detecting defects in textile fabric images. By independent component, we can obtain textile structural features of fabric-free images. By phase congru- ency, structure information is reduced, which can distinguish the defect region from the defect-free regions. Finally, we have the detecting result from binary image which is obtained by a thresh- old step, Compared with other algorithms, the proposed method not only has robustness with high detection rate, but also detects various types of defects quite well.

Semantic Segmentation Using DeepLabv3+ Model for Fabric Defect Detection

Currently, numerous automatic fabric defect detection algorithms have been proposed. Traditional machine vision algorithms that set separate parameters for different textures and defects rely on the manual design of corresponding features to complete the detection. To overcome the limitations of traditional algorithms, deep learning-based correlative algorithms can extract more complex image features and perform better in image classification and object detection. A pixel-level defect segmentation methodology using DeepLabv3+, a classical semantic segmentation network, is proposed in this paper. Based on ResNet-18,ResNet-50 and Mobilenetv2, three DeepLabv3+ networks are constructed, which are trained and tested from data sets produced by capturing or publicizing images. The experimental results show that the performance of three DeepLabv3+ networks is close to one another on the four indicators proposed(Precision, Recall, F1-score and Accuracy), proving them to achieve defect detection and semantic segmentation, which provide new ideas and technical support for fabric defect detection.

Global Fabric Defect Detection Based on Unsupervised Characterization

Fabric texture intelligent analysis comprises the following characteristics:objective detection results,high detection efficiency,and accuracy.It is significantly vital to replace manual inspection for smart green manufacturing in the textile industry,such as quality control and rating,and online testing.For detecting the global image,an unsupervised method is proposed to characterize the woven fabric texture image,which is the combination of principal component analysis(PCA)and dictionary learning.First of all,the PCA approach is used to reduce the dimension of fabric samples,the obtained eigenvector is used as the initial dictionary,and then the dictionary learning method is operated on the defect-free region to get the standard templates.Secondly,the standard templates are optimized by choosing the appropriate dictionary size to construct a fabric texture representat ion model that can effectively characterize the defec-free texture region,while ineffectively representing the defective sector.That is to say,through the mechanism of identifying normal texture from imperfect texture,a learned dictionary with robustness and discrimination is obtained to adapt the fabric texture.Thirdly,after matching the detected image with the standard templates,the average filter is used to remove the noise and suppress the background texture,while retaining and enhancing the defect region.In the final part,the image segmentation is operated to identify the defect.The experimental results show that the proposed algorithm can adequately inspect fabrics with defects such as holes,oil stains,skipping,other defective types,and non-defective materials,while the detection results are good and the algorithrm can be operated flexibly.

Realization of Orthogonal Wavelets Adapted to Fabric Texture for Defect Detection

The wavelet adapted to the fabric texture can be developed from the orthogonal and normal series which are selected randomly by means of Monte Carlo method and op timized by adding certain constraint conditions.Then the fabric image can be decomposed into the subimages by the adaptive wavelet transform and the horizontal and vertical texture information will be perfectly contained in the subimages. Therefore this method can be effectively used for the automatic inspection of the fabric defects.

A Novel One-Dimensional Projection Based Method for Fabric Texture Representation

Automated defect detection in woven fabrics for quality control is still a challenging novelty detection problem,while the efficient representation of fabric texture is essential for it.This paper presents a novel method for fabric texture representation.Benefiting from the characteristics of the weaving process,the major texture information of woven fabric is concentrated in the warp and weft directions.Thus,the proposed method is firstly to project the image patch along warp and weft directions to obtain projected vectors containing warp and weft informations.Secondly,the obtained vectors instead of image patch,are used to extract the features that are able to represent fabric texture.Finally,the t-test is applied to verifying the usefulness of the proposed method in discriminating defective and normal fabric textures.The experiments on various defective samples demonstrate that the method yields a robust and good performance in representing fabric texture and discriminating defects.

Strain-induced magnetism in ReS_2 monolayer with defects

We investigate the effects of strain on the electronic and magnetic properties of ReS2 monolayer with sulfur vacancies using density functional theory.Unstrained ReS2 monolayer with monosulfur vacancy（Vs） and disulfur vacancy（V（2S））both are nonmagnetic.However,as strain increases to 8%,VS-doped ReS2 monolayer appears a magnetic half-metal behavior with zero total magnetic moment.In particular,for V（2S）-doped ReS2 monolayer,the system becomes a magnetic semiconductor under 6%strain,in which Re atoms at vicinity of vacancy couple anti-ferromagnetically with each other,and continues to show a ferromagnetic metal characteristic with total magnetic moment of 1.60μb under 7%strain.Our results imply that the strain-manipulated ReS2 monolayer with VS and V（2S） can be a possible candidate for new spintronic applications.

基于改进YOLOv5算法的织物缺陷检测

基于现有织物缺陷检测算法受疵点尺寸与织物纹理背景的影响导致检测精度较低,同时检测模型过于复杂,难以部署到工控设备上,无法满足织物缺陷实时检测等现状,提出一种改进YOLOv5算法的织物缺陷检测算法。以YOLOv5算法为基准模型,采用跨阶段部分连接残差网络替代原模型的主干网络,增强模型上下文特征信息学习能力;将SimAM注意力机制融入到模型中,提升对有用特征的提取能力,抑制无用纹理背景特征的干扰;引入WIoU与Varifocal Loss损失函数,提高回归框准确性的同时降低负样本权重;最后,针对织物的小目标疵点难以检测的问题,提出增加小目标检测层的方法,提高模型的检测能力。试验结果表明:该研究算法能够快速准确地检测织物疵点,精确率与mAP分别达到86.46%与84.4%,与基准模型相比,分别提高6.16个百分点和5.8个百分点。

改进YOLOv5的织物缺陷检测方法

为了在不增加网络参数量的条件下提升深度学习方法对织物缺陷检测的精度,提出了一种基于改进YOLOv5的织物缺陷检测方法。通过深度卷积改造通道注意力,剪裁最大池化优化空间注意力,并通过二者构建的双级联注意力机制来搭建特征提取子网络,从而提高网络对缺陷区域纹理和语义特征的提取能力;采用鬼影混洗卷积改进特征融合子网络,强化对提取特征的筛选,在降低模型参数量的同时,改善缺陷信息丢失和无效信息冗余问题;在检测端引入具有角度损失的新型损失函数SIOU,来促进真实框和预测框的拟合并提升对缺陷预测的准确性。实验结果表明:改进的YOLOv5方法在降低YOLOv5基准模型复杂度和计算量的同时,与YOLOv7等六种先进方法相比,可获得更高的检测精度,相较原模型mAP@0.5值提高了2.6个百分点,mAP@0.5:0.9值提高了1.3个百分点。

基于轻量化YOLOv7的织物疵点检测算法研究

由于检测工艺的不完善和外界因素的影响,织物疵点检测过程中会存在目标漏检和误检的情况,并且为了在移动设备和嵌入式设备中部署,提出了一种基于轻量化YOLOv7的织物疵点检测算法(LFD-YOLOv7)。首先,针对YOLOv7算法网络结构复杂和参数量较大的问题,结合GhostNet网络构建EGM模块来取代主干网络中的ELAN模块,降低了网络的复杂度和计算瓶颈,增强网络的学习能力;其次,基于ShuffleNetv2的思想,将其与残差网络相融合构造了S-SPPCSPC模块,使网络更加轻量化;然后,引入CA注意力机制来抑制背景噪声对目标检测的影响,提高小目标的准确率;最后采用SIoU损失函数来优化输出预测框边界,提高算法收敛速度。试验结果表明:与YOLOv7算法相比,LFD-YOLOv7算法平均检测精度提升了5.59个百分点,参数量减少了30.3%,检测速度达到41帧/s,满足纺织工业生产对织物疵点的准确性和实时性要求。

基于改进Res-UNet网络的织物瑕疵图像识别方法

复杂花色织物的纹理和色彩常常是非规则的,导致织物表面瑕疵识别难度较高。针对上述问题,研究一种基于改进Res-UNet网络的织物表面瑕疵图像识别方法。采集织物图像并对其实施灰度化、去噪以及直方图均衡化处理,利用蝙蝠算法求取最佳提取网络层数,通过增加特征提取网络层数改进Res-UNet网络,利用改进后的Res-UNet网络识别织物表面瑕疵,并且采用迁移学习算法进一步优化识别模型的参数,实现织物表面瑕疵准确识别。结果表明:本文方法应用下,无论是素色样本,还是花色样本,其识别系数均达到0.9以上,相比基于标签嵌入方法的织物瑕疵识别方法和双路高分辨率转换网络的布匹瑕疵检测方法,本文方法对复杂花色样本的轮廓系数识别更高,适用性更好,识别能力更强。