Treatment for Stitched Scar Formed Due to Accident? (photo)

Hello I had an accident 4 years back for which area on my mustache was cut and was stitched. Now as u can see from the picture it has formed a scar due to which no hair is growing on that part. I like to know the best technique to camouflage it, should i opt for hair transplant, as few grafts of hair will cover it or should i opt for Micro-pigmentation ? Which is the best and what can i expect from this two?