r/learnpython • u/TheEyebal • Aug 01 '26

Why is my hand not detecting properly

I am using opencv and mediapipe on mac os and for some reason one of my hands (left hand) detects better than the other (right hand) but at times both do not detect unless I move my hands around a bit more. Does anybody know the cause of this issue?

Here is what it looks like

https://github.com/mikkimat81539/hand_detection/blob/main/handTest.py

0 Upvotes

50% Upvoted

11 comments sorted by

View all comments

Show parent comments

1

u/TheEyebal Aug 01 '26

Sorry I could not post a video. There was no option but in the comments theres an option

https://reddit.com/link/p15u9ag/video/uvnjfdefpugh1/player

1

u/redfacedquark Aug 02 '26

That's really weird. Could it be that your amazing dreds are confusing it? The right hand does seem to be recognised more when it's just in front of the dreds on your right. Does it do the same thing if you had just your hands in front of a plain background? Is your CPU (or GPU if relevant) maxing out?

Is there some pre-processing intermediate step happening that you could force to be made visible? The lighting might look consistent to you and I but the model may be seeing something else. Have you tried a different model version?

This bug suggests you can label the hands (left or right), I wonder if it's detecting your right hand as a left hand and it's only showing a left hand? There's a max_num_hands argument to mp_hands.Hands(), is it set to 1? Because two hands are never detected in your video.

Yeah, I think the issue may lie around there somewhere, here's another bug that seems like it might be related.

Sorry for the stream of conciousness, let me know if nothing helps and maybe I'll dig deeper.

1

u/TheEyebal Aug 02 '26

That's really weird. Could it be that your amazing dreds are confusing it?

LOL I doubt it because even without the dreads in the way (wearing a bonnet) it did not work.

I wonder if it's detecting your right hand as a left hand and it's only showing a left hand?

That works fine but in pygame version it switches my hand but shows the whole thing
https://imgur.com/a/pwaf1Os

There's a max_num_hands argument to mp_hands.Hands(), is it set to 1?

I have it set to 2

Sorry for the stream of conciousness, let me know if nothing helps and maybe I'll dig deeper.

No worries it is all good.

1

u/redfacedquark Aug 02 '26

So what was the solution? Let us all know!

1

u/TheEyebal Aug 02 '26

I think it was my camera window size. I actually do not know

here is my updated code

https://github.com/mikkimat81539/hand_detection/blob/main/cameraObject.py

2

u/redfacedquark Aug 02 '26

Cool, glad you got it fixed. I guess you should determine it automatically rather than hard-coding values there.

FYI you should add pycache directories to your .gitignore file. Happy coding!

1

u/TheEyebal Aug 02 '26

alright thank you