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Why Are the Ends of a Line Scan Image Dark?
The ends of a line scan image sit at 0.77 of the center from cosine fourth falloff. A 1.3 gain fixes brightness but leaves SNR at 0.88, so shape the light 1.3 times…
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An 850 nm Band-Pass Filter Erases Factory Lights but Leaves Sunlight
An 850 nm band-pass filter erases factory LED light but keeps sunlight. What remains shrinks by the overdrive factor, not by the shorter exposure: a 40-level swing drops to 2 levels with the…
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Brightness Augmentation Cannot Move Shadows or Highlights
Brightness, gamma and noise augmentation change pixel values only and cannot move shadows or highlights. When the elevation drops from 45° to 30°, the highlight on a 1 mm radius chamfer shifts about…
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Gaps in a Clear Conformal Coating Show Up Under UV Fluorescence
A transparent coating reflects the same 4 % as bare solder mask, so white light cannot find it. Under 365 nm only its glow remains, but without an OD 4 long-pass and a…
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Does Memory-Bank Anomaly Detection Need to Remember Every Normal Patch?
Storing every normal patch takes 6.29 GB and a 1 % coreset 62.9 MB, yet search still costs 2.58 trillion multiply-accumulates per image. Search time caps the coreset ratio, and overdetection on normal…
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A Mono Camera Catches PCB Color Differences When You Choose the Wavelength
With 625 nm light on a mono camera, 80 μm of copper exposed through a green mask images at 4.9 px, while the red channel of the color version of the same sensor…
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Why Does a Lightweight Model Lose the Finest Defects First?
A 30 μm trace nick, 3 px at 10 μm/px, drops to 0.75 of a cell at student output stride 4 and can vanish whatever the distillation temperature. Stride 2, T = 2…
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Moving Parts Are Frozen by How Long the Light Stays On
Imaging pins moving at 1,000 mm/s at 24.5 μm/px, keeping blur under 0.5 px means the light must go off within 12.25 μs. A 10 μs pulse at 4× overdrive leaves 0.4× the…
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In Edge Inspection, Input Drift Shows Up Before Accuracy Drops
Lens contamination and light degradation show up in reference luminance and sharpness before accuracy drops. A per-frame p99 alarm fires once every 100 frames, so thresholds go on λ = 0.05 EWMA values…
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On Thick Parts, Silhouette Measurement Error Comes from the Backlight’s Angle
Gauge a 3 mm thick metal part on a diffuse backlight and the edge smears over 7.6 px; switch to collimated light with 0.29° divergence and it narrows to 1.5 px. In exchange,…
