基于卷积神经网络的印刷品颜色缺陷检测

Detection of Printing Color Defect Based on Convolutional Neural Network

目的提取样本图像颜色直方图特征对卷积神经网络进行训练,达到快速、高准确率检测图像颜色缺陷的目的。方法将标准图像从RGB颜色空间转换至HSV颜色空间,通过改变图像H,S,V三分量值获取训练样本和测试样本;在HSV颜色空间中非均匀量化图像的颜色直方图,得到所有训练样本和测试样本的颜色直方图特征;利用样本图像颜色直方图特征训练卷积神经网络,然后对测试样本进行检测,研究检测的速度、准确率,并将该检测方法与逐像素、超像素、BP神经网络和支持向量机方法进行对比。结果对于图片尺寸为512×512的彩色图像,卷积神经网络检测单幅图片的平均检测时间约为57.66 ms,训练样本图像为50000张时,卷积神经网络方法对10000张测试样本进行检测的准确率为99.77%。结论卷积神经网络方法在保证高准确率的前提下大幅提高检测精度,对于印刷品色差缺陷在线检测具有良好的应用价值。

The work aims to train the convolutional neural network(CNN)by extracting color histogram features of sample images,so as to achieve the purpose of detecting image color defect quickly and accurately.RGB color space of standard image was converted to HSV color space and training and testing samples were obtained by change of H,S and V component in image.The color histogram of image was non-equally quantized in HSV color space,and then all of the color histogram features of training and testing samples were obtained.The CNN was trained by color histogram features of sample image,and then the testing sample image was detected to study the detection speed and precision.Finally,this method was compared to each-pixel,super-pixel,BP and support vector machine(SVM)recognition methods.For the color image of 512×512,the mean detection time of each image by CNN was 57.66 ms.When the number of training samples was 50000,the detection precision of CNN for 10000 testing samples was 99.77%.Therefore,the detection method of convolutional neural network can significantly improve the detection precision while ensuring the accuracy and has good application value in on-line color defect monitoring of printing.