I think it's a QR code, but it is fiendishly difficult, and I suspect there is more than one solution.

I can work out the sixes and the obvious ones but then it becomes a bit of guesswork. Any hints?

Solved 4 times in almost 4 years, very telling.

If I told you it´s completely logical except last 9 dots with 20 possible solutions only, you probably wouldn´t believe. Still, it´s true! :D

SPOILER (to make it completely logical + some more ;) ):
R1/c1-6,c11,c18,c20-25
R4/c1,c3-4,c6,c9,c12,c14,c20,c25
R16/c2-5,c8,c10,c13-15,c17,c19,c23,c25
R21/c1,c6,c9,c11,c13,c17,c20,c25
R23/c1,c3-4,c6,c9,c12,c15,c20,c22-23,c25
R25/c1-6,c9,c12,c14,c20-25.

By the way, please, if you (will) have solved some of following hanjies, would you add some spoilers? I believe not to be the only one to thank you :)

http://www.hanjie-star.com/picross/laser-robot-12021.html
http://www.hanjie-star.com/picross/love-bug-11987.html
http://www.hanjie-star.com/picross/rain-cloud-10163.html
http://www.hanjie-star.com/picross/diagonal-symmetry-1--9777.html
http://www.hanjie-star.com/picross/foxy-it-s-snowing--9278.html
http://www.hanjie-star.com/picross/raar-figuur-3782.html
http://www.hanjie-star.com/picross/rainy-day-1226.html
http://www.hanjie-star.com/picross/face-1190.html.

Added hints for face and rainy day Joe.

This is so devious! :)

Thanks Joe!

That really sucked. Had to come back to it multiple times, across multiple months to finally get it, even with Joe's hints. Good luck to anyone else who feels like losing a good portion of their life to this puzzle.

Still one 50/50 guess after joe's hints (which were great!)

Thank you for the SPOILER, Joe!

All of Joe's hints, and it still took me 30 minutes.

Hard, but almost logical. Few guessing at end, but possible.

Thank you very much Joe for cues! Otherwise, it is a nightmare to solve!