Refine image edges
Despeckle grain so keys, silhouettes and masks cut cleanly. Nothing is uploaded.
- Your files are never uploaded
- Processed on your device
- Works offline
- Free, no sign-up
Drop your images here
Images · up to 10 files, 100 MB each
or paste with Ctrl+VLive preview
Settings
No settings needed. Add your files and convert.
Nothing is uploadedHow it works
Add noisy images
Drop in grainy scans or phone shots headed for keying.
Apply gentle refine
A 3x3 median pass smooths speckles while keeping real edges.
Download cleaned PNGs
Preview smoother fills, then key or mask from the refined copy.
Quiet noise before the real cut
Sensor grain, scanner dust and JPEG mosquito noise all masquerade as backdrop variation that forces keying tolerance higher than art deserves, chewing into hair and fabric along the way. This refiner runs a classic three-by-three median filter that replaces each pixel with the middle value of its nine neighbours per channel, erasing lone hot specks and dark pits while preserving genuine step edges. The cleaned plate keys at lower tolerance, silhouettes trace smoother hulls and mosaics average truer colours because the statistical outliers no longer drag local means astray.
Median filtering suits pre-press precisely because it does not blur: unlike Gaussian softening that drags edge pixels across boundaries, the median picks an actually-observed neighbour value, so text stays legible and hair strands stay distinct while salt-and-pepper vanishes. One pass tames light phone noise and scan dust; heavy astro or underwater grain may want two passes from the refined copy rather than a stronger single blur that would melt detail. Always refine before keying, never after, since post-key medians round alpha rims into grey halos.
When to refine and when to stop
Reach for refining when flat skies band into speckles, white sweeps show grey freckles or screenshots carry single-pixel compression glitter that keys into pinholes. Product sweeps, green cloth and blueprint scans benefit most, because their broad fills should be statistically uniform and any deviation is almost certainly noise. Portraits with intentional film grain, star fields and pointillist art should skip it, since the very texture audiences cherish reads as noise to the filter and would be needlessly flattened into waxy pastel patches.
PNG outputs preserve the refined values losslessly for downstream masking, while JPG would immediately re-sprinkle artefacts and defeat the purpose. Keep noisy originals archived, refine copies for working plates, and compare at one hundred percent to confirm dust lifted without turning stubble to plastic. If edges feel too crisp after cleaning, follow with feathered keying rather than extra median passes, letting alpha softness rather than colour smearing carry the naturalism.
Cleanup performed at your own bench
Grainy originals often document private spaces that should not travel merely to be tidied, so median computation proceeds wholly within your tab. Enhancement clouds routinely upload full-resolution frames to GPU queues and keep before-after pairs for model training, whereas here neighbourhood sorting plus PNG encoding unfold in local memory cleared on exit, ensuring bedrooms, prototypes and sensitive scans remain observable only by you during preparation for keying and publication.
There is no subscription, no queue and no watermark: open Refine image edges when speckle threatens a key, cleanse up to ten frames, download the smoothed PNGs and close the tab. Only the tool code lingers for offline sessions, never your photographs. Re-run preserved noisy masters whenever pipelines change, because sources stay bit-identical and each refinement is a fresh, reversible working copy rather than an overwrite.
Questions
Are noisy photos sent to a server?
No. Median filtering runs in your browser. Images never leave your device.
Is it free?
Yes. Free to use with no sign-up, no watermark and no daily limits.
Will it blur my photo?
Very little. A 3x3 median removes single-pixel speckles but keeps real edges sharp, unlike a blur. Fine film grain may soften slightly.
Should I refine before or after keying?
Always before. Refining first lets you key at lower tolerance with cleaner edges. Refining after keying rounds alpha rims.
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