The　digital　post-processing　is　needed　to　restore　the　image　of　high　quality　from　the　blurring　image　output　directly　from　optical　sparse　aperture　imaging　systems.　The　common　method　for　post-processing　is　the　Wiener　filter,　where　the　important　parameter　is　the　point　spread　function　(PSF)　which　should　be　known.　The　Wiener　filter　will　deconvolve　the　convolution　effect　if　the　PSF　is　the　precise　impulse　response　of　the　optical　sparse　aperture　system.　Usually　it　is　hard　to　measure　the　PSF　experimentally.　On　the　contrary,　it　is　easy　to　calculate　the　PSF　based　on　designed　array　configuration　of　the　optical　sparse　aperture　system.　In　order　to　evaluate　whether　the　calculated　PSF　is　adaptable　to　the　image　restoration,　a　theoretical　analysis　of　the　image　restoration　has　been　done　by　using　these　two　kinds　of　PSFs.　The　results　show　that　the　calculated　PSF　works　well　in　the　case　that　the　co-phasing　error　is　small,　while　the　measured　PSF　is　ineffective.