!! Warning: This hanjie is a linea, it is only logical with the constraint that the picture consists of a single curved line, thus each black cell has exactly two of its four nearby cell blacks (except the two ends) !!

Faceless portrait

Regarding the technics, here are the main things to know for now:
We can't have any 2x2 square nor any "T". Then, edge-logic can be used easier.
Moreover, when we have a turn, we can place cross in the angle. When we have a segment, we can place cross along the line (except in the extremities).
Any area which is isolated from the rest by cross is necessarily empty.
If both the ends are found, we must extend the curve "everywhere that is necessary".

Difficulty : ****

Tested, logical (as a linea).
Edge-logic can be usefull.
Good blackenage.