为了提高介质阻挡放电(dielectric barrier discharge,DBD)的工业应用效率,深入理解DBD的形成机理,基于数字图像处理技术,提出了一种利用不同曝光时间放电图像的灰度直方图(gray level histogram,GLH)来识别DBD丝状或均匀放电模式的新方法。研究结果表明:由于丝状放电图像是由不同灰度级的像素点构成,所以随着曝光时间的逐渐增大,对应放电图像像素点的灰度级均逐渐增大,GLH逐渐向右偏移,半宽度明显变宽;而均匀放电图像基本上是由单一灰度级的像素点构成,所以随着曝光时间的逐渐增大,对应放电图像像素点的灰度级也逐渐增大,GLH也逐渐向右偏移,但半高宽基本保持不变。故利用不同曝光时间放电图像的GLH能够较为简单、有效地识别不同放电模式的DBD。
In order to improve the industrial efficiency of dielectric barrier discharge (DBD) and to deeply understand the formation mechanism of DBD, we proposed a new method based on the digital image processing technology to classify the filamentary and homogeneous discharge modes of DBD by using gray level histogram (GLH) of discharge images under different exposure times. Because the filamentary discharge image is constituted by pixels with different gray levels, the gray level of discharge image becomes larger with increasing the exposure times, the corresponding GLH can gradually shift to right, and the full-width at half-maximum {FWHM} of GLH becomes wider significantly. While the homogeneous discharge image is almost constituted by pixels with one gray level, the gray level of discharge image can also become larger with increasing the exposure times, the corresponding GLH can also gradually shift to right, however, the FWHM of GLH remains almost constant. Therefore, the results indicate that the method is not only effective but also simple to classify the DBD modes.