Paper character imaging: separate bright strokes from a dark field
The source paper example shows three lines of bright numeric characters on a dark rectangular field. A red bar creates a practical starting point for checking character contrast and spacing on this print/substrate combination.
Match the reader to the actual print polarity before judging recognition performance.
Real camera capture
- Light in sourceLS-2BS14738-RGBW · red
- EvidenceReal application-lab image
- Imaging kitCamera, lens and fixture proposed
- AcceptanceValidate on representative parts
Explore it in 3D
Camera and available lens CAD are published models. Lens and light envelopes use printed dimensions. The linked station uses its published base size and column height; carriage, brackets, fittings, parts and spacing are illustrative. Confirm load, travel, fasteners and clearances before ordering. Light paths explain the arrangement and do not simulate optical performance. Representative part geometry is illustrative, not reconstructed inspection evidence. The specimen and lighting angle are representative, not dimensions or settings recovered from the source capture.
Lighting application-lab catalog capture
What the camera saw
Cropped from the source test sheet; original test annotations are retained. Captures are not generated or enhanced. Drag a comparison slider, or open any image full size.
The challenge
Background shade, ink density and print texture can change stroke contrast without changing the intended text.
A positive light-on-dark image needs different segmentation behaviour from a dark-on-light print.
How it was solved
The source captions this as paper character inspection with a red bar. It does not identify the ink chemistry or explain why the characters appear bright.
Test the real print and substrate with the proposed monochrome camera. Keep character polarity and spacing in the reader setup rather than assuming the source recipe transfers to other materials.
Why it works
- 1
A selected wavelength can change the reflected contrast between a print and its background; the supplied image records the observed result.
- 2
Readable-looking strokes are evidence of contrast, not a measured OCR result or a verified text match.
Lighting application-lab catalog capture
Evidence you can inspect
Three numeric lines and their spaces are visible as light strokes against a dark field.
The catalog identifies paper character inspection and the red 147 mm bar.
No decoded text, recognition confidence, print-size measurement, speed or repeatability result is given.
From image contrast to a production decision
What to validate on your part
- 01
Keep the true strings
Build a labelled set covering all required characters, separators and line layouts.
- 02
Vary print and substrate
Include accepted density changes, weak strokes, background texture and damaged print.
- 03
Measure substitutions separately
Record wrong characters as well as no-reads under the final focus and exposure.
From the demo to your test bench
Parts in this setup
LightTested
LS-2BS14738-RGBW
147 x 32 mm Bar light (LS-2BS14738-RGBW)
Red 147 × 38 × 27 mm bar explicitly identified in the paper-character example. The RGBW catalog suffix lists individual colour options; this kit selects red.
$259.00
In proposed setup
CameraOur pick
MV-CS050-10GM(NPOE)
Hikrobot MV-CS050-10GM(NPOE) 5 MP GigE area scan camera, IMX264, Gen 2 basic version, Mono, Without PoE
5 MP monochrome global-shutter camera proposed for a contrast trial. Confirm field, sampling, exposure and algorithm on the actual application.Not available in the United States. Available for delivery to other countries.
$819.00
In proposed setup
LensOur pick
LS-KF1628M-ML
16mm, F2.8, 1.1", C-mount, Macro lens (52 mm (-0.25X) to 546 mm (-0.03X)) (LS-KF1628M-ML)
Proposed 16 mm C-mount macro lens at its printed 0.1x magnification / 152 mm working-distance pair. The proposed 2448 × 2048 sensor with 3.45 µm pixels gives a derived 84.456 × 70.656 mm field; confirm focus, coverage and residual distortion on the real sample.
$319.00
In proposed setup
Camera test stationOur pick
LS-BT-XZ-G-6-6045
Camera stand with XZ adjustment and glass tray, height 600 mm (LS-BT-XZ-G-6-6045)
600 mm column, 600 × 450 mm breadboard, XZ adjustment, glass tray and two lighting holders as listed. Proposed bench fixture; confirm loads, travel and camera/lens clamps.
$629.00
In proposed setup
"Tested" identifies the part named in the source. "Our pick" is a proposed alternative or supporting part. Confirm colour, optics, controllers, power supplies, cables and mounting before ordering.
The set-up
| Tested light | LS-2BS14738-RGBW, red |
|---|---|
| Source camera / lens | Not specified in the source image caption; proposed parts below |
| Proposed lens point | 0.1x at 152 mm, printed lens pair |
| Derived proposed field | 84.456 × 70.656 mm = sensor dimensions / 0.1x; not a source test field |
| Bar housing (printed) | 147 × 38 × 27 mm |
| Mounting (proposed) | LS-BT-XZ-G-6-6045; 600 mm column, 600 × 450 mm base, glass tray and two included lighting holders |
Mount the optics with intent
The station is an optical test bench, with its two lighting holders included in the catalog listing. The 3D column and base follow the published height and footprint. Carriages, clamps and part supports are schematic: confirm camera screw pattern, lens support, light fasteners, permissible load and actual travel before ordering.
Complete the electrical system
Select a controller against the exact light voltage, drive mode and power, then confirm camera data/power/I/O cables and a suitable PC. These are not silently added to the proposed optical kit.
Build this system
Start from this setup, adapt it to your part.
The configurator opens with this study's camera, lens, light and station picked. Swap any part, check fit and price, then buy or ask for a quote.
Camera and available lens CAD are published models. Lens and light envelopes use printed dimensions. The linked station uses its published base size and column height; carriage, brackets, fittings, parts and spacing are illustrative. Confirm load, travel, fasteners and clearances before ordering. Light paths explain the arrangement and do not simulate optical performance. Representative part geometry is illustrative, not reconstructed inspection evidence. The specimen and lighting angle are representative, not dimensions or settings recovered from the source capture.
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Make the next trial specific.
Tell us the part size, smallest defect or tolerance, available working distance, material and line speed. Include what a good part and a reject look like.
About this case study: the photos and camera images come from the application laboratory of the maker of the lighting and optics we sell, imaged on the parts shown; your results depend on your part, camera and set-up. This is an application-lab study, not a LumaSpec customer deployment. Source figures are reported results; proposed components require a fresh trial. The 3D scene illustrates the arrangement and does not simulate imaging performance.