Lenticular Interlacer
Make a stripe image to place beneath a lenticular lens sheet. LPI is the number of lens ridges per inch; DPI divided by LPI is the output pixel period of one lens. This tool divides that period among 2–6 uploaded views and samples each output pixel at its centre. Recomputing the phase over the full image width avoids cumulative drift when the period is not an integer number of pixels. The tool cannot measure the actual sheet pitch, printer scaling or physical alignment, so test-print the calibration band before using the result.
Key features
- Upload 2–6 PNG, JPEG or WebP views, or try a three-view example
- Set LPI, DPI, physical size, stripe direction and lens phase for pixel-accurate view assignment
- Centre-cover crops mixed image ratios and composites transparency over white
- Inspect physical size and pixels per lens/view, with a low-resolution warning
- Export a PNG with a same-phase colour calibration band and 10 mm rule, plus image-only PNG
- Write print DPI into PNG pHYs metadata and cancel long generation
How to use
- Upload 2–6 view images in viewing order, or load the three-view example.
- Enter the lens sheet's actual LPI, printer DPI, and intended image width and height in mm.
- Choose vertical or horizontal ridges and adjust phase if alignment tests call for it.
- Check pixels per view and the preview, then save the PNG with its calibration band.
- Test-print at actual size/100%, measure the 10 mm rule, align the lens and correct phase or print scaling as needed.
Use cases
- Test a two-view flip image for a small lenticular print
- Turn three or more motion frames into a stripe image for a lens sheet
- Estimate whether a lens pitch and printer DPI offer enough pixels per view
- Use the colour band to check lens direction, phase and print scale
Frequently asked questions
How do LPI and DPI differ?
LPI is the number of lens ridges per inch on the sheet; DPI is output pixels per inch. At 40 LPI and 600 DPI, each lens spans 15 pixels, averaging 5 pixels per view for three views.
What if DPI is too low?
If DPI ÷ LPI ÷ views is below one pixel, some view bands can disappear and generation is blocked. One to two pixels is allowed but highly sensitive to printer interpolation and alignment; fewer views or genuinely higher print resolution may help.
Will a downloaded PNG print at its stated size?
The PNG carries pHYs resolution metadata, but print software may ignore it or fit the image to a page. Select actual size/100% and measure the printed 10 mm rule.
What does the calibration band show?
Each view appears as a different colour at the same pixel coordinate and phase as the image. The band adds 12 mm below vertical stripes or to the right of horizontal stripes, preserving the common starting edge in one file.
Will this work with any lens sheet?
No. Actual pitch, ridge direction, mounting and cut alignment, and printer scaling matter. Test prints and sheet alignment are necessary; professional print quality is not guaranteed.
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Uploaded photos and results are processed in browser memory and are not sent to a server. Closing the page discards the working images.
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