机织物图像的高精度纠偏及效果验证

为解决织物图像采集过程中出现的倾斜现象,从织物本身的纹理特征出发,根据织物图像中纱线的间隙方向与纱线一致性的原理,提出一种新的织物图像偏斜纠正方法,对纱线的间隙进行倾斜纠正,实现了整幅织物图像的有效纠偏。并利用织物图像行投影亮度离散度与纠偏角度之间关系及织物纬纱密度测量的结果,对纠偏的效果进行了验证。实验结果表明,0.05°的纠偏精度可以达到理想的效果,可为后续织物密度的自动识别及织物组织的识别奠定基础。     

织物中经纬纱线特数的自动识别技术

介绍了基于织物图像的经纬纱特数测试方法。该方法采用间接测量,即计算机图像分析得到的是织物中经纬纱线的投影直径,再由投影直径在考虑纱线压扁系数、织物毛羽等因素的情况下换算成纱线特数,经特数圆整即可得到经纬纱特数。在织物紧度不大、纱线存在间隙时,采用该方法测得的纱线特数准确、稳定。     

织物经纬密度的数字化分析系统

织物是由经纱和纬纱交织而成的,通过织物的扫描图像,可以发现经、纬两个方向上纱线与纱线之间的间隙的亮度信号有明显的变化规律。利用此规律。可以确定织物图像上经纬纱线的位置。分割经纬纱线,从而求出准确的经纬密度。     

应用纱线序列图像的电子织物构建

为检测纱线条干均匀性对织物外观的影响,在纱线条干图像测量的基础上,提出了一种基于纱线序列图像的电子织物的构建方法。通过建立织物组织变化模型和光照模型,将纱线直径值与基元组织点外观灰度纹理分布相结合,构建电子织物外观数学模型。实验中通过将采集的纱线序列图像进行图像分割和形态学运算等处理,获取纱线直径数据,代入到构建的织物外观数学模型中,实现基于纱线序列图像的电子织物的模拟并且相关参数可调。通过选择合理的织物结构参数,提出的电子织物模型能够真实的反映纱线条干均匀性对织物外观的影响,准确预测布面效果。     

采用色纺纱图像的真实感色织物模拟

为解决色织物产品设计周期长,试织打样耗时费力的问题,提出一种采用色纺纱图像的真实感色织物的模拟方法。首先采集彩色纱线图像,运用阈值分割、形态学处理得到纱线主体,获取纱线主体的上、下边界和中心线,进而得到原始纱线图像的主体部分;接着根据椭圆模型和正弦曲线模型对纱线主体图像进行处理,得到纱线在二维织物表面中的形态;最后根据色纱循环和织物组织变换模型来改变经纬纱的覆盖关系,实现了真实感条纹型和格子型色织物的模拟。模拟结果表明：本文算法能够模拟不同种类色织物的织造过程,真实地反映织物的外观效果,且能够调整织物组织和色纱循环参数,提高了现有模拟算法的真实性和适应性。     

织物组织识别方法研究

运用扫描仪获取织物的反射图像,在织物辅助分析系统中读入扫描图像,对图像进行数字处理,通过分析织物的经纬纱线浮点中纤维的纹理方向而判断其属于是经浮点或纬浮点,从而达到判别机织物组织的目的。尤其对于经纬同色或经纬密度相同的织物,此方法具有很好的效果,解决了以往通过经纬异色织物中组织点颜色或灰度值的深浅或组织点的形状不同判断等技术不能解决的问题。     

基于平滑滤波和分水岭算法的重组织织物图像分割

针对带有重组织的织物图像特点,提出了一种根据纱线颜色进行图像分割的方法。首先将织物图像转化为Lab颜色模式,采用混合中值滤波算法滤除扫描噪声;其次通过设置色差容许值改变高斯权值的平滑滤波算法进行滤波,去除织物图像中的重组织阴影和同颜色纱线纹理,保留纱线颜色特征;然后提取织物图像的色差梯度,通过分水岭算法进行图像分割,获得区域标记图像;最后将颜色相近的分割区域进行合并,得到织物图像的分色索引图像。实验结果表明,提出的算法可以对重织物图像进行较为准确地分割。     

基于自适应小波变换的织物密度测量

应用自适应小波变换技术以实现机织物密度的自动测量。先运用Wiener2和直方图均衡技术对织物图像进行预处理,增强图像的纹理特征;接着选取自适应小波技术对织物图像进行分解;再对分解得到的子图像进行二值、平滑等后处理;最后通过分析后处理图像的经纬纱线信息得到织物密度。试验结果证明,运用该方法能够准确测量3种基本组织的织物密度,是一种行之有效的方法。另外,还简要介绍了自适应小波的构造技术。     

基于MATLAB图像处理的织物纱线直径测量

针对织物中纱线细度的测量,先用切片技术制作织物切片获得其切片图,再用MATLAB图形处理函数对其进行处理以利于测量,然后使用CU-2纤维细度仪中的显微图像分析应用软件包测量出纱线直径,并与直接测量从织物中拆下的纱线直径进行了比较。结果表明通过MATLAB图像处理纱线切片的方法所测得的纱线直径准确可靠。     

基于MATLAB的机织物密度自动检测

对机织物用MATLAB语言进行图像处理，实现机织物经纬密度自动检测进行了研究。提出用小波变换对机织物图像进行分解和重构，将机织物经向和纬向信息分离出来，再对变换后的图像进行二值化和平滑处理。得到与背景完全分离的纱线分布信息，自动计算出机织物的经纬密度。经实验验证，所得结果相对误差为3‰，准确度较高。     

应用混色纱纹理信息的纬编针织物模拟

为研究数码混色纱纬编针织物的外观色彩及纹影的模拟方法,利用图像处理技术对采集的图像进行平滑去噪,得到剔除细节的模糊图像,在Lab 空间下运用彩色图像硬聚类算法对平滑后的图像进行聚类分割,得到混色纱主体图像,获取其左右的边界和中心线信息;然后在经典的Pierce 线圈模型的基础上,利用混色纱主体图像的廓线信息完成由纱线到线圈圈弧和圈柱的映射;最终根据不同组织的圈弧和圈柱的覆盖关系,得到基本纬编针织物组织。结果表明,提出的纱线映射线圈算法,通过织物组织结构及密度可模拟混色纱纬编织物的混色色彩及外观纹影。     

Computer simulation of plain woven fabric appearance from yarn photographs

This article proposes a method for simulating plain woven fabric appearance based on photographs taken by still camera of actual yarns along their lengths. The survey mathematically models the transformation of yarns from a straight circular cylinder to a flattened and crimped form in the fabric structure. The simulation is performed by yarn images that are obtained by image processing techniques and resized according to mathematical models developed by means of the software prepared. Transforming circular yarn cross-section to elliptical one for simulating yarn flattening and modelling the crimped shape of yarn by an elastica curve are both convenient and realistic. The simulation of plain woven fabric can be performed by a method based on raster graphics. This article provides a model for yarn shape in fabric structure as well as a method for simulating plain woven fabric appearance. This method may be used in textile industry for design and quality control.     

Effect of surface modification and knife penetration angle on the Quasi-Static Knife Penetration Resistance of para-aramid fabrics

The focus of this paper is to describe the effect of change in surface friction of single layer para-aramid (Twaron^®) square woven fabric and change in knife penetration angle on its Quasi-Static Knife Penetration Resistance (QSKPR). The surface friction of fabric was changed by depositing SiO₂ on its surface by using water glass as a precursor. Six different knife penetration angles (0°, 22.5°, 45°, 67.5°, 90° and 135°) were selected. Untreated and treated fabric samples were compared for change in QSKPR. It was observed that the deposition of SiO₂ on the surface of Twaron^® fabric increased the surface friction which resulted in the increase in QSKPR. The response of fabric against QSKPR changed from partial yarn cutting to individual yarn cutting in fewer steps and load was distributed to a larger area due to decrease in yarn slippage. The change in penetration angle changed the distance, knife cutting edge travelled to cut each next yarn(s) and when this distance increased, the QSKPR was reduced. The post-penetration image analysis of damaged fibres showed that the load distribution among warp and weft yarns was complementary and change in penetration angles changed the distribution of stabbing load among the warp and weft yarns. When yarns with higher tensile strength and less slippage were loaded, the fabric showed highest resistance to penetration. A QSKPR prediction model was also proposed at the end.     

竹节纱织物竹节分布均匀性评价方法

针对二值化图像的重心、面积2个指标,利用图像技术对竹节纱织物表面竹节分布的均匀性进行评价。在计算机辅助生成竹节分布图像基础之上,随机生成10 cm×10 cm的竹节分布图,通过考核各图的重心分布位置及各图之间的面积分布变异系数,综合考量竹节纱织物的竹节分布情况。测试结果显示:当竹节密度较低时,减小竹节各个配比之间的长度差异能有效减少竹节不匀的产生。     

织物经纬密度自动测量实用技术:1.测量方法

为克服单一图像处理技术在检测高紧密、歪斜变形、绒面和结构不均匀等织物的结构参数时存在的困难和低精度问题,提出一种自动测量机织物经纬密度的新方法。运用力学拉伸矫正和清晰化与图像处理的组合技术快速测定机织物的经纬密度。研究证实,基于组合技术的纱线排列密度图像测量算法易实现,且对织物结构的图像识别具有普适性,可标准化和实用化。     

Evaluation of diamond bar patterns on fabric surface using an image analysis technique

The main aim of this work is to study of the effect of yarn periodic irregularities on the plain weave fabric appearance using an image analysis method. The pattern of fabric faults was simulated using a prepared computer program. In the experimental stage, two different types of yarn were prepared. The first yarn was produced with a certain wavelength and the second yarn was prepared with a strong periodic irregularity using an open-end spinning machine. The wavelength of the open-end yarn fault was measured by using an Uster 4 automatic evenness tester. For practical examination, the yarns were used as weft in a shuttle loom machine and two types of fabrics were produced. Using image processing, the number and size of the diamond bar patterns, and also the theoretical wavelength of the weft yarn, were calculated. The wavelengths calculated theoretically were compared with the actual wavelengths of the weft yarns. The results showed an acceptable accuracy of the method.     

Weave pattern recognition by measuring fiber orientation with Fourier transform

An effective method based on measuring the fiber orientation of yarn floats with two-dimensional Fourier transform (2-D FFT) is proposed to recognize the weave pattern of yarn-dyed fabric in the high-resolution image. The recognition process consists of four main steps: 1. High-resolution image reduction, 2.Fabric image skew correction, 3.Yarn floats localization, 4. Yarn floats classification. Firstly, the high-resolution image is reduced by the nearest interpolation algorithm. Secondly, the skew of the fabric image is corrected based on Hough transform. Thirdly, the yarn floats in the fabric image is localized by the yarns segmentation method based on the mathematical statistics of sub-images. Fourthly, the high-resolution image is corrected and its yarns are segmented successively according to the inspection information of the reduced image. The fiber orientations are detected by 2-D FFT, and the yarn floats are classified by k-means clustering algorithm. Experimental results and discussions demonstrate that, by measuring the fiber orientation of yarn floats, the proposed method is effective to recognize the yarn floats and the weave pattern for yarn-dyed, solid color, and gray fabrics.     

结构参数对超高分子量聚乙烯织物导热性的影响

为了提高服装热量的传导,采用导热率较高的超高分子量聚乙烯(UHMWPE)纱线作为纬纱与涤纶进行交织制成织物,并以电热片作为热源,通过铂电阻测温仪测量距离热源边界0、2、4 cm处织物表面温度随时间的变化。采用变量分离法测试纤维种类、纱线线密度、织物密度以及织物组织结构等因素对超高分子量聚乙烯织物导热性的影响。结果表明:含UHMWPE纱线交织物的导热性明显好于涤纶/涤纶和涤纶/锦纶交织物,且纱线越粗、织物密度越大、组织单元内纱线交织次数越少,织物导热性越好。