[HN Gopher] Breakthrough in 3D scanning means results are 4500% ...
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Breakthrough in 3D scanning means results are 4500% more accurate
Author : rbanffy
Score : 52 points
Date : 2021-06-30 20:34 UTC (2 hours ago)
(HTM) web link (www.lboro.ac.uk)
(TXT) w3m dump (www.lboro.ac.uk)
| [deleted]
| xbar wrote:
| A margin of error of 13.8cm in current 3D scans of human bodies?
| I think their baseline is bogusly large.
| yorwba wrote:
| They're using a commercial scanner:
| https://www.sizestream.com/technology
|
| The margin of error is less surprising if you consider that
| they're interested in the precision of measurements like
| _hinged upper bust circumference_ , not the position of raw
| points in a point cloud. According to the paper "Erroneous
| measurements occur because of the 3 D Body Scanner's incorrect
| placement of anthropometric landmarks or the physical
| positioning of body parts which increase measurement paths
| against the algorithms. The 3 D Body Scanner's incorrect
| landmark and measurement placement, in this study, causes
| measurements with a range of up to 32.9 cm (M=14.6 cm; SD=12.67
| cm)."
|
| I.e. if the scanner confuses your arm for your leg, that's
| going to throw off the measurements a lot.
|
| It seems like SizeStream could easily improve their product by
| applying some basic filtering to remove outliers.
| tapland wrote:
| Oh yeah. And a grainy surface would give a higher surface
| area which if you used that as a measurement for creating
| clothes would be bad, but less bad with improved surface
| measurements.
| changoplatanero wrote:
| Yes that seems too big to be true
| savant_penguin wrote:
| That looks like basic filtering by z score
|
| Someone should also try median filtering, would that be
| considered another breakthrough?
|
| Edit: just read the code, they also filter by the distance to the
| median.
| londons_explore wrote:
| > average margin of error for current 3D scanning machines is
| around 13.8cm
|
| Sorry _whaaat_?? No 3D scanner I 've ever used has a margin of
| error of 13cm!! Typically for person-sized objects margins of
| error can be expected to be 1mm typically.
| riotnrrd wrote:
| Here's the code:
| https://github.com/UoMResearchIT/Gryphon/blob/main/gryphon.p...
|
| Based on a brief read, it looks like the "breakthrough" is
| discarding the two measurements in a point group that are the
| furthest outliers from the mean. That can't be it, can it?
| Because that's an afternoon's work for an intern, not a
| breakthrough.
| madengr wrote:
| More accuracy may be better, but I'd like to see a quick method
| of extracting analytic geometry from a 3D scan.
|
| We have laser scanners and Faro arms at work, and in the end
| it's a person manually entering the geometry into Solidworks as
| the point cloud is useless.
| TeeMassive wrote:
| If it was that stimple, then why it was not implemented and/or
| widely used before?
| cma wrote:
| Almost every variation on strategies like that has been used
| with depth data. Median filters are more popular.
| jjoonathan wrote:
| It was, but the authors have an incentive to pretend it's
| novel, the press has an incentive to pretend it's novel, and
| the patent office has an incentive to pretend it's novel.
| FridayoLeary wrote:
| The fact that the article mentioned 4500% three times, twice in
| the title alone, kind of warned me to take their news with a
| pinch of salt.
| oezi wrote:
| Too late for you to hold up the train of progress, a patent was
| already filed. /s
| TeMPOraL wrote:
| _You_ being the operative word, as in 21st century, patents
| are the _definition_ of holding up progress.
| verdverm wrote:
| That can be true, and so is the idea that if you could not
| reap the rewards of your inventions, you wouldn't invest
| the effort because it could only be a cost sink. It's more
| nuanced and contextual than that. That said, the patent /
| trademark (probably any similar system) has up and down
| sides
| TeMPOraL wrote:
| That's why I said "in the 21st century". As far as I
| studied this, patents are a really solid idea _in theory_
| , and perhaps they even worked as advertised at some
| point in the past. But the way they work today, they're
| thoroughly gamed - patent owners get the benefits, the
| society doesn't get its promised returns. But I agree,
| it's a pretty nuanced topic.
| verdverm wrote:
| The idea of having time and protection to recoup your
| investment still applies today. Being "in the 21st
| century" doesn't remove this trade-off nor imply that
| progress is held up because of patents. It could be that
| progress suffers more without patents. Humanity and
| society works better with incentives and freedom of
| preferences
| sacred_numbers wrote:
| Something can be remarkably simple and still a breakthrough at
| the same time. Handwashing, for example, is one of the greatest
| medical breakthroughs of all time despite its simplicity.
| Scene_Cast2 wrote:
| On the data side, a simple but effective algorithm is
| "lightweight coresets". A couple of line of NumPy, but strong
| guarantees and nice properties.
| 1123581321 wrote:
| Lightweight corsets (shapewear using hose-like material)
| were also a simple, effective breakthrough.
| ethbr0 wrote:
| It made Spanx into a ~$750M company.
| sen wrote:
| Yes but telling people who already know how to wash their
| hands that they should wash them for "more than 1 second and
| less than 1 hour" isn't novel, which is effectively what
| they're trying to sell here.
|
| There's nothing in this "breakthrough" that isn't already
| being done anyway, and the comparison stats are completely
| made up. 13.8cm resolution in current scanners? Have they
| even used a 3D scanner made after the millennium turned?
| binbag wrote:
| 4500%!!!!!!!!!!!!!!!!!!!!!!!!!!!11
|
| That's 45,000,000 ppm!!!!!
| s_gourichon wrote:
| Percentage are broken in many cases because they are ambiguous,
| and often difficult to compose. +50% then -50% is not identity
| but ratio 3/4.
|
| A plain explicit ratio is sometimes better. Ratio in decibel,
| or "doubling number" can sometimes be valuable alternative,
| could be used more often.
|
| +1 doubling -1 doubling is identity. Same for decibels.
| OJFord wrote:
| In case it's missing, I think parent's tongue is firmly in
| their cheek - point is things like '4500%' are often
| manipulatively rendered that way to sound massive, vs. '45x'
| for example, which means the same, is just as massive, but
| perhaps doesn't sound _as_ crazy?
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