Images & photos

Image threshold mask

Create a binary luminance mask with manual or automatic Otsu thresholding.

Image threshold mask
Esc to restore

Make it yours

Inputs and settings

Adjust the inputs, then update the preview. Sliders and selectors update directly.

Files stay on your device

See it take shape

LOCAL & PRIVATE

Preparing your workspace…

Your files and work stay in this page. Export anything you want to keep.

A clear answer. Here’s how.

Computes weighted RGB luma. Manual mode compares with the selected level; automatic mode maximises between-class variance over a rounded 256-bin luma histogram, choosing the first tied maximum and falling back to 127 for a constant image. White means luma strictly greater than threshold. Output is opaque; source alpha is ignored. Not AI object segmentation. Supports PNG/JPEG/WebP up to 10 MB and 4 million decoded pixels per file. Browser decoding and single-frame PNG re-encoding remove source metadata/colour profiles; no files leave this device.

Keep going in images & photos.

All images & photos tools
SVG to PNG converterImage brightness, contrast and gammaFlat-colour background cutoutTrim transparent image borders