Niveaux de gris — conversion locale
0.90
Étapes: choose files, adjust options, export. exemple: sample color blocks demo. processus: local in browser, no upload. Tool: Rec.601 grayscale conversion, keep alpha when PNG/WebP. Soft limits ~25MB / 8192px apply.
Comment ça marche
Pick a photo, apply grayscale, download. Processing never leaves this tab.
Règles
For each pixel Y=0.299R+0.587G+0.114B; R=G=B=Y; alpha unchanged.
- Rec.601 coefficients match common luma practice.
- Alpha channel is copied unchanged.
- Export re-encodes; JPEG drops alpha.
- Animated GIF: first frame only.
Exemple
Sample four-color blocks become gray with distinct brightness levels.
Bons cas
- Print preview without color ink assumptions.
- Accessibility contrast drafts.
- Stylized black-and-white exports.
Frequently asked questions
Uploaded?
No—everything is local.
Which formula?
Rec.601: 0.299R+0.587G+0.114B.
Can I undo?
Not after download; keep the original file.
Same as CSS filter?
We rewrite pixels, so the saved file is truly grayscale.
Transparent PNG?
Transparency is kept when exporting PNG/WebP.
Related tools
Questions ou retours
Quelque chose n’est pas clair, cassé ou manquant ? Rédigez un message ci-dessous — nous lisons chaque note.