Plenoptic camera can sample object in the way of 4D light fields in a single snapshot, which is different from conventional camera. Vignetting in the plenoptic camera will result in non-uniform intensity distribution of 4D light field data. We propose a method in this paper to address this problem according to exposure fusion and patch-match. The uniform intensity distribution of 4D light field data can be enhanced by our approach. This work can be treated as a preprocess step for further application on 4D light field data. As more details are kept, the quality of depth estimation and digital refocusing with 4D light field data is increased by our method compared with previous method.