A　hybrid　phase　retrieval　method　with　the　assistance　of　off-axis　digital　holography　is　proposed　for　imaging　objects　on　the　surfaces　of　a　transparent　medium　with　uneven　thickness.　The　approximate　phase　distribution　is　obtained　by　a　constrained　optimization　approach　from　the　off-axis　hologram,　and　it　is　used　in　an　iterative　procedure　for　retrieving　the　complex　field　of　the　object　from　the　Gabor　hologram.　Furthermore,　principal　component　analysis　is　introduced　for　compensating　for　phase　aberrations　caused　by　the　medium.　Numerical　simulations　and　optical　experiments　were　carried　out　to　validate　the　proposed　method.　The　quality　of　the　reconstructed　image　is　improved　remarkably　compared　to　only　off-axis　digital　holography.　(C)　2017　Elsevier　E.V.　All　rights　reserved.