Hashes provided on Sourceforge:
https://sourceforge.net/projects/opencvlibrary/files/opencv-win/3.1.0/
opencv-3.1.0.exe | 2015-12-18 | 115.1 MB
SHA1: 51b7bbc30dba948851be5ba3ddecf4797d7c32e1
MD5: e86cfcb2e2fa4cc7232c5965ce98ed66

opencv-3.1.0.exe | 109.8 MB
SHA224: 3761ea9df1da806b25ced5c685a63cccda9d6581bb9a4bfa11b93885
SHA256: 0cbb10fab967111b5b699a44cb224f5d729f8d852d2720cbd5cdb56d8770b7b3
SHA384: 474f554f9103c56d4c4aa75dc022dd0c87b4207784521450d380128b3688431d35046b95f5449b3f4a24a79067624b93
SHA512: 6937b0cf5bf7264156210886d17001806c86f3bbd20c894328b5887451f9c8df2e5495892f920f7c93ec9e8c4e886cb8afb9874ebf76bd84c2d9fda5664b56e2

Deprecated Hashes
MD5: e86cfcb2e2fa4cc7232c5965ce98ed66
SHA1: 51b7bbc30dba948851be5ba3ddecf4797d7c32e1

Verification
MD5: Match
SHA1: Match