Merge pull request #2 from matrixik/master

Fix: make ImageMagic and GraphicMagic works on Windows
Update README.md w/ instructions for resize.go

As a followup to issue #1 which @matrixik found
Add go-opencv binding.
Return both size of original file and new file.
Update README.
Merge pull request #3 from lazywei/master

Add go-opencv binding comparing.
Add rez resizer
Update README.md
Update results

rez was updated with a small speed optimisation
GOMAXPROCS is set to 4 so all resizes are able to use parallelism
Merge pull request #4 from bamiaux/rez

Add rez resizer