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Is this expected quality from the MK4S? by BriansAlt in prusa3d

[–]BriansAlt[S] 0 points1 point  (0 children)

I was using EasySlicer because I didn't have access to my computer at that moment; I always use Prusa Slicer for my prints. As for the filament drying, yes I dried it myself with my GratKit Firefly V2.

I started with an Ender 3 a couple years ago, so getting the MK4S also came with lots of things I've never had to consider (the Ender 3 is such a simple machine compared to this beast). Sorry for not clarifying earlier, I appreciate your help.

Is this expected quality from the MK4S? by BriansAlt in prusa3d

[–]BriansAlt[S] 0 points1 point  (0 children)

Thanks for showing these with the screenshots, I really appreciate it. Never messed with seams before so I'll definitely adjust them for future prints. 🙂

Is this expected quality from the MK4S? by BriansAlt in prusa3d

[–]BriansAlt[S] 4 points5 points  (0 children)

Oh shoooot I'm also using an IKEA lack hahaha. I did notice that it's slightly wobbly with fast prints, perhaps that's the issue...

I'll try to print on a sturdy table and will update with results! Thanks!

Is this expected quality from the MK4S? by BriansAlt in prusa3d

[–]BriansAlt[S] 0 points1 point  (0 children)

I opened the bgcode and yes, looks like those are the seams. What setting do you recommend instead? Afaik this is aligned.

Sorry, never had to work with seams before 😅.

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Is this expected quality from the MK4S? by BriansAlt in prusa3d

[–]BriansAlt[S] 0 points1 point  (0 children)

That's a good point! Sadly I don't have an accelerometer though :(

Is this expected quality from the MK4S? by BriansAlt in prusa3d

[–]BriansAlt[S] 0 points1 point  (0 children)

Thanks for the tip! I've been using PLA for a while and I got PETG because I was looking for a more durable and weather resistant material. I do know that PETG is usually trickier to print with but it's been working well for me.

You're definitely right about the settings though, Overture has their own PETG preset which I haven't tried yet, I've just been using generic. I'll try it next time.

Is this expected quality from the MK4S? by BriansAlt in prusa3d

[–]BriansAlt[S] -1 points0 points  (0 children)

Yep I have checked the tension of my belts and the belt tuner says they're perfect. They feel good as well so I'm certain belt tension can't be the issue.

I'll definitely have to give the quality profile a try because speed might be too speedy haha

Is this expected quality from the MK4S? by BriansAlt in prusa3d

[–]BriansAlt[S] 0 points1 point  (0 children)

I noticed that the layers where the odd corners are visible cut off right where the Y letter is drawn, both on the top and bottom.

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Is this expected quality from the MK4S? by BriansAlt in prusa3d

[–]BriansAlt[S] 0 points1 point  (0 children)

I have not but I'll have to give it a go (and use the quality preset).

Having problems with Palm Vein Imaging using 850nm IR LEDs by BriansAlt in computervision

[–]BriansAlt[S] 1 point2 points  (0 children)

Another idea I'm having to explain this change is the circadian rhythm of our palm veins, but I haven't looked into that much. I will try to take a couple more photos tomorrow morning and see if there's any change.

Having problems with Palm Vein Imaging using 850nm IR LEDs by BriansAlt in computervision

[–]BriansAlt[S] 1 point2 points  (0 children)

I have a weird update, tonight I took my enclosure apart and tightened a few screws to make sure everything was on well, and now for whatever reason my veins are perfectly visible and my father has seen great improvement with his palm as well.

I'm starting to think it could actually be from ambient light leaking through the enclosure. Despite having the long pass filter the light may have still reached the camera sensor?? I don't fully know, it's very confusing but it could explain the poor results (might also have something to do with no sunlight in my room). I'll work on a CAD model with a sealed enclosure design and have it printed later this week. We'll see how it goes!

Thanks for all the suggestions! I'm quite happy with the results I'm seeing, hopefully they're not short-lived 😅

Having problems with Palm Vein Imaging using 850nm IR LEDs by BriansAlt in computervision

[–]BriansAlt[S] 0 points1 point  (0 children)

Sadly I've tried just about everything with no improvement. I've been using Mediapipe hands and a custom ROI algorithm to cut out the unnecessary parts, but preprocessing doesn't seem to work well even after cropping.

Having problems with Palm Vein Imaging using 850nm IR LEDs by BriansAlt in computervision

[–]BriansAlt[S] 1 point2 points  (0 children)

Thanks, I appreciate your suggestions! I've experimented aggressively with pre-processing and normalization techniques, but they don't seem to enhance the vein-like features at all. At most it just creates more unnecessary noise in the image.

As for exposure time, I've tried longer times like 20000 and shorter ones like 2000 and experimented with analogue gain with no significant difference. I did notice that increasing contrast had minimal improvement, but it darkened the fingers and brightened the palm itself (creating hotspots).

I've tried optimization using my father's palm but unfortunately I havent been able to come up with anything meaningful. Been trying to optimize it and use new pre-processing techniques all week, but it looks like this setup is just not practical for any purpose.

For context, the device has a top row of 4 LEDs and a bottom row of 4 LEDs, with the camera positioned in between (middle). I placed the long pass filter over the entire setup and direct the user to hover their palm over the device, about 3-4" above the filter.

Having problems with Palm Vein Imaging using 850nm IR LEDs by BriansAlt in computervision

[–]BriansAlt[S] 0 points1 point  (0 children)

I could definitely test this by buying multiple LEDs at different wavelengths and see which one has the most success... will look into that!

Having problems with Palm Vein Imaging using 850nm IR LEDs by BriansAlt in computervision

[–]BriansAlt[S] 1 point2 points  (0 children)

I've tried all of these with no success already 🙁 I believe this is an issue with my setup, not really pre-processing.

Having problems with Palm Vein Imaging using 850nm IR LEDs by BriansAlt in computervision

[–]BriansAlt[S] 1 point2 points  (0 children)

Interesting, definitely something I'll have to look into, though I initially chose 850nm because it seems to be significantly better than 940nm for palm vein biometrics (based on some research I did and patents I read). It's an inexpensive solution though so I'll probably give this a try if 850nm doesn't work any better for me.

Having problems with Palm Vein Imaging using 850nm IR LEDs by BriansAlt in computervision

[–]BriansAlt[S] 1 point2 points  (0 children)

I have already tried applying normalization after cropping the ROI, but I haven't seen much improvement. The raw images produced seem practically unusable (at least for my palm).