fix default labelconfig
[DOC] update user doc
[DOC] update doc
Merge pull request #49 from sealhuang/fix-default-label

fix default labelconfig
[DOC] update user doc
[DOC] update user doc
[DOC] update user doc
move inverse function
add inverse process
Merge pull request #50 from sealhuang/add-image-inversion

Add image inversion function and update user document