ImportError: DLL load failed: %1 is not a valid Win32 application
Solution 1:
The ImportError message is a bit misleading because of the reference to Win32, whereas the problem was simply the opencv DLLs were not found.
This problem was solved by adding the path the opencv binaries to the Windows PATH environment variable (as an example, on my computer this path is : C:\opencv\build\bin\Release).
Solution 2:
You could try installing the 32 bit version of opencv
Solution 3:
I just hit this and the problem was that the package had at one point been installed in the per-user packages directory. (On Windows.) aka %AppData%\Python. So Python was looking there first, finding an old 32-bit version of the .pyd file, and failing with the listed error. Unfortunately pip uninstall by itself wasn't enough to clean this, and at this time pip 10.0.1 doesn't seem to have a --user parameter for uninstall, only for install.
tl;dr Deleting the old .pyd from %AppData%\python\python27\site-packages resolved this problem for me.
Solution 4:
Or you have to rebuild the cv2 module for win 64bit.
Solution 5:
All you have to do is copy the cv2.pyd file from the x86 folder (C:\opencv\build\python\2.7\x86\ for example) to C:\Python27\Lib\site-packages\ , not from the x64 folder.
Hope that help you.