To obtain optimized results of SDBD（surface dielectric barrier discharge） exposed electrode with four shapes of ladder

thread

zigzag

and steamer

we studied the distribution of light intensity by using the pixel gray value approach in image processing and the principle that the light intensity is positively related with the discharge intensity and charge density. The results show that the discharge intensity distribution is consistent with the Gaussian distribution

and the charge distribution is similar too. Changing the shape of the electrode has a remarkable influence on discharge distribution. Elongated electrode will discharge more fiercely compared to the normal discharge electrode

but ladder electrode will discharge weakly. Zigzag electrode will distinctly non-uniformly discharge in span-wise direction

and there is a phenomenon that the strongest and lowest light intensity occurs alternately with uniformly spacing. It is revealed that jagged electrodes significantly has a dimensional effect. Therefore

it is shown that changing the shape of exposed electrode to form point discharge or superposing E-field to enhance electric intensity can optimize SDBD.