Effects of Exposure Parameters on The RGB Channels of Clean and Polluted Insulators Images

Flashover due to contamination is still an important discussion in efforts to increase the reliability of medium, high, and extra high voltage systems. The imaging technology offers several advantages in assessing the insulator condition. The camera settings play a very vital role as it directly determines the output image. But this aspect has not been investigated in more detail. This study exhibited the effect of exposure parameters on the image of clean and fan-shaped polluted insulators. The exposure parameters including ISO, shutter speed, and aperture were varied. In qualitative analysis, the output image from the visible light camera was observed visually. In quantitative analysis, the oval-shaped selection area was applied to the porcelain part of insulator. The RGB channels from the selection area were then separated. Furthermore, the curve shape and the curve highest peak were observed. The results revealed that the given variation in exposure parameter created visual impacts on the reflection level of non-porcelain objects and the sharpness level of pollutant distribution and density. The judgement of exposure parameter influence was more accurate based on the RGB channels. The changes in exposure parameter caused a shift in the curve position. There was a significant difference in the curve shape between clean and polluted insulators. Thus, the findings from this study could provide an overview regarding the optimal selection of exposure parameters for the insulator condition assessment.