The　processes　of　warping　and　rendering　in　Depth　Image-Based　Rendering　(DIBR)　are　usually　performed　without　a　reference　image.　Thus,　an　effective　and　fast　reference-free　(RF)　image　quality　assessment　(IQA)　model　devised　for　DIBR-synthesized　views　is　more　favorable.　To　this　aim,　this　research　propose　a　novel　RF　IQA　method　of　DIBR-synthesized　views　based　on　Energy　Loss　Estimation.　Firstly,　considering　that　the　geometric　distortions　caused　by　the　processes　of　warping　and　rendering　might　increase　the　high-frequency　(HF)　information　of　a　DIBR-synthesized　view,　the　influence　of　the　geometric　distortion　on　the　visual　quality　of　a　synthesized　view　can　be　effectively　evaluated　by　estimating　the　HF　information　energies　of　a　given　DIBR-synthesized　view　in　the　log-gabor　domain.　Secondly,　we　estimate　the　energy　loss　in　the　process　of　JPEG　compression　as　the　image　complexity,　which　is　used　to　overcome　the　problem　of　different　amounts　of　HF　information　contained　in　different　content　images.　Finally,　the　proposed　RF　DIBR-synthesized　IQA　metric　is　obtained　by　using　the　energy　loss　in　JPEG　compression　to　normalize　the　HF　information　energy　in　the　log-gabor　domain.　Experiments　conducted　on　two　public　datasets　demonstrate　that　the　proposed　method　is　advantageous　over　the　relevant　state-of-the-art　RF　IQA　metrics.　©　2020　Technical　Committee　on　Control　Theory,　Chinese　Association　of　Automation.