Light field imaging is a promising technology for 3D computational photography. As Light Field images are represented for multiple views, their subjective evaluation is a very demanding task. Hence, identifying reliable objective quality assessment methodologies plays a very important role. In this paper six objective quality metrics; PSNR-Y, PSNR-YUV, SSIM-Y, MSSSIM-Y, FSIM-Y and HDRVDP2-Y are assessed for five state-of-the-art codecs at various bit-rates. Moreover, the metrics are computed in the linear, perceptually uniform and perceptual quantizer spaces. The results are compared against those of a subjective study and is concluded that the average FSIM-Y is the most reliable metric. The paper also introduces maps of the objective metrics to evaluate the quality dispersion among the different light field image views.