Speed up ToImage function
Speed up ToImage function

1. Turn IplImage.imageData to Go's slice
2. Use SetNRGBA function instead of NRGBA.Set

lazywei/go-opencv,lazywei/go-opencv,ronoaldo/go-opencv,lazywei/go-opencv,go-opencv/go-opencv,go-opencv/go-opencv,go-opencv/go-opencv,ronoaldo/go-opencv,ronoaldo/go-opencv