Our example images keep turning shiny patches into defects

RaviChan1085 · 17 Jul 2026, 20:14 UTC

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RA
RaviChan1085
Our planned presenting reflective components for surface inspection in a small finished-parts production cell has Fairino FR5 presenting a bright-finished enclosure faceplate to a fixed camera. The example images contain bright streaks that shift with small presentation differences, yet those streaks are being labelled as scratches. Before commissioning, i'd like to establish reliable references and image conditions for threshold tuning.

20 replies

JA
JackBrooks0863
Replying to RaviChan1085

Check whether the suspected scratches were confirmed on physical samples under the agreed appearance procedure. Link each image to its sample identity and inspection result first.

6 points
RA
RaviChan1085
Replying to JackBrooks0863

Some labels came from the pictures alone. We still have the samples, but those labels aren't tied to physical inspection results. That's irritatingly circular.

6 points
JA
JackBrooks0863
Replying to RaviChan1085

@RaviChan1085 Mark those labels uncertain and have the samples inspected properly. Then compare images with presentation and lighting controlled; the moving streaks are a useful reflection clue.

12 points
EL
EllaAli0207
Replying to JackBrooks0863

@JackBrooks0863 A scratch's visibility can change with presentation too. Don't let 'moving streak' quietly become the rule for relabelling something acceptable.

14 points
JA
JackBrooks0863
Replying to EllaAli0207

@EllaAli0207 You're right to qualify that. The streak behaviour motivates an imaging investigation; it doesn't replace physical classification under the agreed inspection procedure.

7 points
ME
MeiBrooks0864
Replying to JackBrooks0863

So uncertain isn't the same as good? Where do those images go?

17 points
JA
JackBrooks0863
Replying to MeiBrooks0864

@MeiBrooks0864 Retain their sample identities and undecided status. They shouldn't become confirmed acceptable or defective examples while the physical review remains unresolved.

6 points
RA
RaviChan1085
Replying to JackBrooks0863

Our two comparison folders changed exposure and presentation together. i can't tell which change made the images look better. That comparison needs a caveat too.

8 points
HE
HenryAli0177
Replying to RaviChan1085

On my inspection setup, a folder called 'better lighting' also contained easier samples. The folder name was doing a lot of unearned work.

11 points
RA
RaviChan1085
Replying to HenryAli0177

What did you keep beside each image? i can manage sample ID and settings, but i don't want a form nobody fills in.

3 points
HE
HenryAli0177
Replying to RaviChan1085

On my setup we kept sample ID, exposure, lighting arrangement and presentation condition. Enough to explain a comparison without reconstructing the whole session from memory.

16 points
JA
JackBrooks0863
Replying to HenryAli0177

@HenryAli0177 Those records can support the vision specialist's comparison of image conditions. Holding the representative sample set constant will make an acquisition change easier to assess.

22 points
ME
MeiBrooks0864
Replying to JackBrooks0863

Would a learned model just cope with the lighting differences?

21 points
JA
JackBrooks0863
Replying to MeiBrooks0864

@MeiBrooks0864 Any learned model still depends on reliable labels and representative evaluation. Changing the method doesn't resolve unconfirmed physical defects or an uncontrolled comparison of image conditions.

23 points
EL
EllaAli0207
Replying to JackBrooks0863

And don't tune and test on different pictures of the same physical sample. That isn't the independence the result would suggest.

14 points
RA
RaviChan1085
Replying to EllaAli0207

@EllaAli0207 i'll keep all images of one sample together when we split tuning and evaluation sets. Our file names alone wouldn't have caught that overlap.

21 points
JA
JackBrooks0863
Replying to RaviChan1085

Report missed defects and false rejects separately on the held-out samples. One agreement percentage can hide which mistake your method is making.

15 points
RA
RaviChan1085
Replying to JackBrooks0863

Should undecided physical samples count as misses in that report? i don't want them quietly disappearing just because they're awkward.

12 points
JA
JackBrooks0863
Replying to RaviChan1085

Report the undecided samples and their number explicitly, but don't include them as confirmed-class errors. This preserves the coverage limitation without assigning an unestablished reference label.

6 points
HE
HenryAli0177
Replying to JackBrooks0863

@JackBrooks0863 That helped on my setup. People could see how much remained undecided instead of mistaking a cleaner-looking table for better inspection performance.

21 points

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